Hypoplasia of the thymus in newborns. Thymus: the thymus gland in children. Diseases of the thymus. What is important for parents to know about the thymus gland in children? Thymus hypoplasia in children symptoms and treatment

The thymus gland in children is the central organ, which is located in the middle of the chest.
It is he who is of great importance in the correct formation and subsequent functioning of the child's immune system, and any violations in his work can lead to various complications and the development of pathologies.
What is thymus?
The thymus gland, also known as the thymus, is the main organ of the immune system because it produces, develops, and educates special T cells.
It got its name because of the shape, which is similar to a fork with two teeth.
Interesting!
The thymus looks like a fork in a healthy person, and with pathologies of this area, the gland becomes like a butterfly, taking the form of a thyroid gland. For its proximity to the latter, it was also previously called the thymus gland.
The thymus gland in newborns has a mass of 12 g and grows until the age of 10 years. After reaching the age of 18, it begins to decrease.
The thymus is well palpable when pressed with two fingers in the area of ​​​​the upper part of the sternum, slightly below the fossa of the clavicle.
The thymus gland in children and adults has the same location, but it has the following features due to age:
1. During the time from birth to puberty, the thymus increases by about 3 times: if in newborns it weighs about 12 g, then in adolescents it reaches a size of up to 40 g.
2. By the age of 16, the iron begins to atrophy.
3. Approximately by the age of 24-25, its size is about 25 g.
4. In people aged 60, the thymus weighs less than 15 g.
5. After 80 years, its mass does not exceed 6 g.
In old age, in areas below and on the sides of the thymus, atrophy is observed and adipose tissue forms in their place, and the gland itself lengthens. Such changes are currently inexplicable by science.
Many experts believe that solving this puzzle may contribute to the management of the aging process.
Thymus functions
The thymus gland in children carries out the formation of all systems in the body. Its main functions can be listed as follows:
endocrine;
lymphopoietic;
regulating immunity.
The gland destroys aggressive cells, as it ensures the production of T-cells, which are the main regulators of the immune system.
In addition, the thymus controls the outflow of blood and filters it.
The formation of the gland in a child begins at the 6th week of pregnancy.
Until the age of one year, this organ affects the synthesis of T-lymphocytes through the bone marrow. They protect the baby's body from the following influences:
infections;
bacteria;
viruses.
Hormones produced by the thymus gland are involved in the regulation of almost all processes in the body, performing the following important functions:
decrease in heart rate;
increased protein synthesis;
increase in cell growth and skeleton;
slowdown of the central nervous system;
improving the functioning of the thyroid gland and pituitary gland;
acceleration of the breakdown of sugar;
replenishment of energy reserves.
Thymus hormones carry out the metabolism of the following substances:
carbohydrates;
vitamins;
minerals;
fats;
proteins.
A decrease or increase in the thymus gland leads to a violation of these processes and provokes various pathologies.
Important!
In most cases, malfunctions of the thymus lead to tumor processes and autoimmune diseases. Timely diagnosis and treatment can prevent complications.
Hyperfunction of the thymus
This condition indicates an increase in the thymus gland, which is accompanied by its hyperfunction. As a rule, the pathology is transmitted genetically.
In newborns, it may be due to one of the following factors:
the age of the pregnant woman;
violations in the bearing of a child;
diseases of an infectious nature in a pregnant woman.
If hyperfunction of the thymus is observed in older children, then the cause may be a lack of proteins in the diet, since with their prolonged deficiency, the functions of the organ are impaired in the form of suppression of the immune system and a decrease in the content of leukocytes.
In addition, hyperplasia of the thymus gland in a child can be caused by the so-called lymphatic diathesis.
In this condition, the tendency of the lymphatic tissue to grow abnormally affects the internal organs, including the thymus.
Symptoms in newborns
Diffuse enlargement of the thymus in infants is accompanied by the following manifestations:
1. Body weight at birth is significantly above average.
2. The child gains and loses weight rapidly.
3. The skin is pale, and the mucous membranes have a bluish tint.
4. A network of veins is clearly visible on the chest.
5. There is frequent regurgitation after feeding.
6. There are heart rhythm disturbances.
7. Subfebrile temperature persists, despite the absence of signs of an inflammatory nature.
Often, thymus hyperplasia in infants is accompanied by a cough without additional symptoms of a cold and excessive sweating.
Symptoms in older children
The following manifestations are added to the symptoms in newborns with thymus hyperfunction in this case:
swollen lymph nodes;
lowering blood pressure;
obesity with a healthy diet;
cold extremities;
hypertrophy of the tissues of the posterior pharynx.
At the same time, heart rhythm disturbances and increased sweating become more pronounced.
A decrease in immunity provokes other pathologies in the development of the baby.
For reference!
In female children, in some cases, a persistent increase in the thymus leads to hypoplasia of the organs of the reproductive system, and in male babies, to phimosis.
Hypothyroidism
Hypofunction of the thymus is usually a congenital or primary underdevelopment of the elements of the organ. This condition may develop due to the following factors:
diseases of a viral nature;
diabetes;
the use of alcoholic beverages during pregnancy.
In childhood, such a pathology provokes the following conditions:
accelerated development of the sex glands;
reduction of lymphoid organs;
lymphopenia;
weight reduction;
hypotrophy;
bone growth disorders;
Hypofunction of the thymus gland in children provokes failures of immunological reactivity.
Diagnostics
Diseases and pathologies of the thymus in children are detected using x-rays or high-resolution ultrasound.
The need for diagnostics may appear with the following features in a child:
1. He often suffers from a cold, which turns into pathology in a severe form.
2. There is an increase in lymph nodes.
3. There is a great predisposition to allergies.
When there is suspicion of an increase / decrease in an organ, a specialist may prescribe an endocrine examination and CT scan. The latter method allows you to identify the following diseases of the thymus:
DiGeorge syndrome;
thymoma;
myasthenia gravis;
T-cell lymphoma.
When diagnosing tumors in this area, surgery is usually required.
Important!
Since ultrasound is as informative as an x-ray, many experts recommend not exposing children to radiation once again and choosing an ultrasound diagnostic method.
Treatment
Pathologies of the thymus gland usually occur before the age of six, after which they disappear on their own without special treatment.
At the same time, funds are used to strengthen the immune system, and a special daily regimen and diet are observed.
But in some cases, in order to avoid further complications, measures and therapy are required.
Urgent medical care for diseases of the thymus gland in a child is required if the following symptoms are present:
body weakness;
bradycardia;
apathy.
Treatment for thymus pathologies in children may include the following items:
physiotherapy procedures;
therapy with biostimulants;
the use of immunomodulators;
a diet high in vitamin C;
the use of drugs to stimulate the respiratory center;
prevention of respiratory diseases.
With hyperplasia of the thymus, in some cases it is prescribed surgery before which it is necessary to control blood pressure. It is advisable to perform the operation under local anesthesia.
Without prior preparation before the intervention, the likelihood of adrenal insufficiency in a child increases.
Parents of children who have been diagnosed with dysfunction of the thymus gland should remember that aspirin is contraindicated for them.

The immune system of a child begins to form long before it is born. At the sixth week of pregnancy, the fetus already has thymus is the central organ of human immunogenesis. Due to the fact that it is shaped like a fork, the thymus is also called thymus. The younger the child and the more often he gets sick, the more actively the thymus works, and, accordingly, the more intensively it grows. The growth of the thymus gland slows down when the child is 12 years old. His immune system by this time is already considered formed. In adults, only a reminder remains of the thymus gland in the form of a small lump of adipose tissue. And by old age, the thymus in a person is almost absorbed.

The thymus gland in children - what is it, what is it responsible for and where is it located

The size of the thymus in children: the norm (photo)

The thymus of a healthy child should be no more than CTTI 0.33(CTTI - cardiothymic thoracic index - this is how the thymus is measured). If this index is higher, fixed thymomegaly ( increase) , which can be of three degrees:

I. CTTI 0.33-0.37;

II. CTTI 0.37-0.42;

III. CTTI more than 0.42.

Among the factors that have a direct impact on the increase in the thymus, one can name the pathology of the development of the fetus during, gene anomalies, late pregnancy, infectious diseases suffered by the expectant mother.

ultrasound

Theoretically, it is possible to determine the size of the thymus using radiography and ultrasound examination of the thymus gland. For diagnosis in children, x-rays are used only as a last resort, due to the risk of exposing the child. Usually, ultrasound is enough to get the desired results.

Immunity and thymus: Komarovsky (video)

Hyperplasia and hypoplasia of the thymus

Among diseases of the thymus gland, in addition to thymomegaly, in children one can also find hyperplasia and hypoplasia of the thymus. Hyperplasia of the thymus- this is the growth of its tissues with the formation of neoplasms. BUT hypoplasia- this is a violation of the function of T-lymphocytes due to congenital pathologies of development. These diseases are recorded much less often than thymomegaly, but they require more serious medical intervention.

Thymomegaly: symptoms to see a doctor

What could be the reason for going to the doctor? What symptoms may indicate an enlarged thymus gland in a child?

1. The baby is rapidly gaining (or losing) weight.
2. After feeding, the baby often spits up.
3. The child begins to cough when he lies down (false croup).
4. Often sick with colds.
5. When a baby cries, its skin turns blue-violet.
6. There is a venous mesh on the chest, and the skin is covered with the so-called marble pattern.
7. With an enlarged thymus, the tonsils, adenoids, or lymph nodes can also increase in size.
8. Often in children, arrhythmia and reduced muscle tone are observed.

Treatment of an enlarged gland

Often, with an increase in the thymus gland, drug treatment is not required. The exception is rare complex cases of thymomegaly.

But you should make every effort to. Doctors recommend:

• Taking vitamins and a diet rich in proteins.
• Hardening and sports.
• Compliance with the daily routine.
• Vaccinations for thymomegaly can be done, only you first need to give the child an antihistamine prescribed by a pediatrician.
• Contact with SARS patients should be avoided.
• Avoid eating allergenic food.

And a very important point. If your child has an enlarged thymus gland, he should not take acetylsalicylic acid as an antipyretic. Aspirin can speed up the growth of thymus cells.

Forecasts

The thymus gland works and grows intensively in the first years of a child's life. Then she gets relatively little work. Accordingly, the rate of its growth is markedly reduced. Therefore, an enlarged thymus does not require serious treatment, most often, and up to two years it is completely considered the norm. By the age of 5-6, usually, the thymus stops growing. But this does not mean that she should be left without proper supervision. After all, the formation of immunity of your child and his health in the future depends on it.

PRIMARY IMMUNODEFICIENCY (PIDS).

PIDS with a predominant defect in cellular (T-) immunity is associated with a violation of the differentiation of the stem cell of the precursor of T cells, with a violation of the formation of T-lymphocytes due to agenesis of the thymus, dysplasia or hypoplasia of it. In PIDS with a defect in humoral (B-) immunity, it may be due to a violation of the differentiation of the stem cell of the precursor of B-cells, with the activation of T-suppressors, cytotoxic T-lymphocytes.

With combined PIDS, one or more of the listed factors of combined damage to the T-B-immunity systems or a defect in enzymes that ensure the normal functioning of the immune system may occur.

Clinical manifestations of PIDS are: a decrease in resistance to infections, an increase in the frequency of infectious diseases, the severity and duration of their course, the development of severe and unusual complications, the incidence of infectious diseases caused by microorganisms with low pathogenicity. With a defect in humoral immunity, there is a predisposition to infectious diseases caused by gram-positive bacteria, with a defect in cellular immunity - fungi, viruses, mycobacteria and gram-negative microbes. In PIDS, the frequency of tumor diseases, predominantly of lymphoid tissue, and autoimmune diseases increase.
To understand the pathoanatomical changes in the organs of immunogenesis in PIDS, it is necessary to know that the thymus, both in phylogenesis and ontogenesis of a person, is formed earlier than other organs of immunity (2 months of intrauterine development), is colonized by lymphocytes earlier than other organs, and by the time of the birth of a child is completely formed. Its function as an organ of immunogenesis plays a leading role in the perinatal period and in the first years of a child's life. Therefore, changes in the thymus are of primary importance in assessing the immune system of children, and, consequently, in resolving the issue of the presence of PIDS.
^ AGE CHANGES IN THE THYMUS
In premature newborns and fetuses of 28-30 weeks, the thymus is immature - lobules in the form of layers of reticuloepithelium, not populated or moderately populated by lymphocytes, mature lobules are present, the cortical and medulla layers are clearly visible in them. If an immature thymus is found in a full-term newborn or in a child of the first years of life, this is an indicator of the functional inferiority of the immune system of this child, which may disappear with age. Such immaturity of the thymus is an unfavorable background condition in which infectious diseases occur with a severe course and even death. .

In postnatal ontogenesis, the thymus undergoes age-related involution, which begins at the age of 5–7 years and ends by puberty.
^ AGE INVOLUTION OF THE THYMUS
Adipose tissue develops, which is embedded in the thymus lobules. The lobules decrease in size, the number of lymphocytes in them decreases, the division into the cortical and medulla disappears, Hassall's bodies become homogeneous, partially calcified, their neoplasm stops. At the same time, thymus lobules in the form of small islands are located among adipose tissue and are preserved at any age. Adipose tissue is especially developed during puberty and at the age of 18-20 years. In this case, the thymus has the appearance of a large fatty body. In old age, the adipose tissue of the thymus gradually atrophies and sclerosis.
^ ACCIDENTAL TRANSFORMATION (or involution) of the THYMUS
A sharp decrease in the mass of the thymus, which occurs under the influence of various diseases, trauma, starvation, cooling, was called the accidental involution of the thymus (the Latin word accedentis literally means accident).

The etiology of AT is diverse, which indicates the stereotype of this phenomenon and the absence of any specificity in relation to the agent that caused this thymus reaction. AT is observed in various diseases in children, both infectious and non-infectious nature, with leukemia and malignant tumors, with metabolic disorders, with protein starvation (kwashiorkor), cystic fibrosis, drug exposure, for example, glucocorticoid, cytostatic, radiation therapy. There are 5 phases of thymus AT.

Phase I - begins with the proliferation of pre-T-lymphocytes in the subcapsular zone of the thymus cortex, their differentiation into mature T-lymphocytes intensifies. Phase II should be considered the beginning of involutive processes.

Phase II - the so-called picture of the "starry sky", because. in the cortical layer of the thymus there is an increase in the number of macrophages, while in parallel there is a death of T-lymphocytes due to apoptosis.

Phase III - the death of lymphocytes in the cortical layer with preserved lymphocytes in the medulla. This leads to inversion of the layers of the thymic lobules, and there is a gradual collapse of the cortical layer. There are many mast cells, eosinophils, macrophages, fibroblasts in the interlobular septa. The number of Hassall's bodies increases, they appear in the medulla and even in the cortex, but they are small. Inside the thymic bodies, lymphocytes, neutrophils, eosinophils can accumulate with the phenomena of karyopyknosis and rexis.

Phase IV - devastation of the medullary zone, due to the death of lymphocytes, thymic lobules are collapsed, thymic bodies merge, forming cystically enlarged cavities filled with homogeneous eosinophilic masses, some are calcified. The thymus connective tissue capsule and interlobular connective tissue are enlarged, there are islands of adipose tissue in it, infiltration with lymphocytes, eosinophils, macrophages, mast cells.

Phase V - coarsening of the stroma increases, narrow strands of cell clusters remain from the thymic lobules with the inclusion of thymic bodies in them, which are completely calcified. Large vessels and the capsule are sharply sclerosed; there is adipose tissue among the stroma.

Thus, IV-V phases of AT differ only in the degree of sclerosis of the stroma and its vascular bed.
^ PRIVATE PIDS FORMS
M Orthologically, changes in the thymus in PIDS can be characterized as dysplasia and hypoplasia of the organ.
DYSPLASIA - DISTURBANCE OF THE FORMATION OF THE COMPONENT TISSUE ELEMENTS OF THE THYMUS IN THE INTRAUTERINE PERIOD (EMBRIONAL AND EARLY FETAL PERIOD) and is characterized by the absence or underdevelopment of the reticuloepithelium, the absence (partial or complete) of the thymic lobules by lymphocytes, as well as the violation of the formation in the postnatal period with the appearance of signs of untimely fatty transformation of the thymus. According to this definition, there are several variants of thymus dysplasia. The subsequent classification is given according to WHO (1978).

^ THYMUS DYSPLASIA
- first option - according to WHO, the Swiss type of Glanzmann-Rinicker. Absence or severe underdevelopment of the reticuloepithelium and poor colonization of the lobules by lymphocytes. Severe combined immunodeficiency (SCID), both cellular and humoral immunity are impaired. The type of inheritance is autosomal recessive. In pathogenesis, the defect of the lymphoid stem cell is the main one. Clinically characterized by non-permanent lymph - and leukopenia. Infectious diseases develop in the first months of life, and lead to death at 6-8 months of age. Pathological examination revealed multiple necrosis and inflammatory infiltrates in the skin, which are the source of sepsis. Leiner-type dermatitis, Ritter-type exfoliative erythroderma, or histiocytosis X have been described. Bacterial infections are combined with viral infections - generalized chickenpox, measles giant cell pneumonia, generalized cytomegaly, herpes simplex, adenovirus infection, fungal infections and pneumocysts. This syndrome can be associated with lymphomas, hemolytic-uremic syndrome, hemolytic autoimmune anemia, cystic fibrosis, and hypothyroidism.

The mass of the thymus is reduced by 5-10 times, the reticuloepithelium is underdeveloped, thymic bodies are absent or very small, single. There are very few lymphocytes, there is no division into cortical and medulla layers. The lymphoid tissue of the peripheral organs is in a state of hypoplasia: the lymphoid follicles are not developed, the zones in the lymph nodes are not distinguishable, the tissue of the nodes consists of the reticular stroma, myeloid elements and a small number of lymphocytes.

- second option according to WHO Nezelof's syndrome (alymphocytosis). Thymic dysplasia is characterized by the presence of reticuloepithelium, which forms thymus lobules with multiple glandular structures, Hassall's bodies are absent, lymphocytes are single. Cellular immunity suffers. It is inherited recessively, linked to the X chromosome. The pathogenetic essence is reduced to a violation of the differentiation of T-lymphocyte precursors into mature T-lymphocytes, due to thymus dysplasia. Sometimes patients have a lack of serum Ig, due to impaired differentiation of B-lymphocytes. Infectious diseases - pneumonia, candidiasis, measles pneumonia, generalized BCG-itis, herpes simplex, sepsis caused by gram-negative flora. Life expectancy 1-2 years. The thymus mass is reduced. In the lymph nodes, the spleen, there are few lymphocytes in the thymus-dependent zones, there are plasmablasts. In the bone marrow up to 3% of plasma cells.

- third option according to WHO, it is SCID with adenosine deaminase deficiency. The defeat of the B - and T - cell link is characteristic. Characteristically recurrent infections caused by Candida, pneumocystis, Pseudomonas aeruginosa, cytomegaloviruses, herpes viruses, chickenpox. It is often combined with a violation of the formation of cartilage tissue. Without a bone marrow transplant, death occurs in the first year of life.

It has 2 types of inheritance autosomal recessive (in 40%) - in this form there is no adenosine deaminase enzyme: in this case, deoxyaminazine accumulates, which is toxic to immature lymphocytes (especially T-l). Recessive, associated with the X chromosome (in 50%) - a mutation that affects the protein that is the receptor for IL-2,4,7. Morphological changes depend on the type of genetic defect. With the 1st type of inheritance - the thymus is small, without lymphocytes. In other cases, the lymphoid tissue is hypoplastic with a decrease in T-cell zones and T- and B-zones.
- fourth option according to WHO Di George Syndrome

(hypoplasia or agenesis of the thymus). It is caused by a violation of the development of the 3rd and 4th pharyngeal pockets, from which the thymus, parathyroid glands develop. These patients do not have cellular immunity, tk. there is hypoplasia or aplasia of the thymus, tetany develops, because no parathyroid glands, congenital heart defects and large vessels. The appearance of the face may change: hypertelorism, anti-Mongoloid incision of the eyes, low-set ears, as well as esophageal atresia, hypothyroidism, tetrado Fallot, hypoplasia of the kidneys and ureters. Due to impaired cellular immunity, there is no protection against fungal and viral infections. There are no T-dependent zones in the thymus and spleen. Plasma cells are not affected and the level of immunoglobulins is unchanged. This syndrome is caused by violations of embryogenesis at the 6-8th week of pregnancy.

- the fifth variant according to WHO Louis-Bar syndrome ( ataxia-telangiectasia Louis-Bar). It is characterized by a deficiency of cellular and partly humoral immunity in combination with progressive cerebellar ataxia and peribulbar telangiectasias. Morphologically - thymus dysplasia, the lobules consist of reticuloepithelium, there are no Hassall bodies, a decrease in T-lymphocytes, the lobules are not divided into the cortical and brain zones. Giant cells with hyperchromic nuclei are formed in the reticuloepithelium. In the peripheral organs of immunogenesis, hypoplasia of T-dependent zones. In the cerebellum - atrophy of the cortex with the expansion of the IV ventricle. At microscopy - dystrophy or complete disappearance of pear-shaped neurocytes (Purkinje cells) and the granular layer. Such changes are observed in the anterior horns of the spinal cord, hypotholamus, and demylinization of the posterior columns. In the transverse muscles - secondary atrophy, liver - focal necrosis, fatty degeneration, lymphocyplasmocytic infiltration of the portal tracts. In the kidneys - chronic pyelonephritis. In the lungs - bronchiectasis, abscesses, pneumosclerosis. The combination of ATE with malignant tumors is characteristic: lymphomas, lymphogranulomatosis, leukemias, meduloblastomas, adenocarcinomas, dysgerminomas.

This defect is due to a defect in the final differentiation of T-lymphocytes, as well as an anomaly in the plasma membranes of lymphocytes. It is inherited in an autosomal recessive manner. Often there is a deficiency of Ig A, Ig E, IgG 2, IgG 4. Ataxia develops from the age of 4 (gait disturbance) and gradually progresses. Telangiectasias are found by the 1st year of life on the bulbar conjunctiva, then in other areas. There is graying of hair, sweating, atrophic dermatitis, eczema, skin neoplasms and severe retardation of physical development. Secondary sexual characteristics do not develop. Menses are irregular. Patients live up to 39-41 years.

- the sixth option according to WHO a Bruton's gammaglobulinemia, X-linked . It is characterized by untimely fatty transformation of the thymus. One of the most common primary IDs. With it, there is no serum IgG immunoglobulin or it is low. More often in boys, the beginning of 8-9 months: when the number of immunoglobulins from the mother decreases. There are recurrent conjunctivitis, otitis media, pharyngitis, bronchitis, pneumonia, skin infections (pyoderma) are more often caused by staphylococcus aureus or Haemophilus influenzae. Cellular immunity is not impaired. Autoimmune diseases (rheumatoid arthritis, SLE, dermatomyositis) often develop in Bruton's disease. Sharply reduced or no B-lymphocytes. L\u and spleen do not have germinal centers, and l\u, spleen, bone marrow and connective tissue, no plasmacytes, palatine tonsils in the form of rudiments, T-lymphocytes remain normal.
- seventh option Chronic granulomatous disease (CGD, fatal granulomatous disease of children) is characterized by a defect in the bactericidal function of phagocytes with repeated purulent-granulomatous processes in the skin, lungs, lymph nodes, liver, with hypergammaglobulinemia, anemia, leukocytosis.
There are 2 forms of CHB

^ 1. The most common, inherited by a recessive type, linked to the X chromosome. Boys (up to 4 years old) get sick, it is difficult.
2. It is rare, inherited in an autosomal recessive manner, children of both sexes are ill, it proceeds more easily. The first clinical symptoms are skin lesions in the 1st month of life in the form of eczematous changes with suppuration in the auricles and around the nose, plus regional lymphadenitis, then the liver, lungs, lymph nodes, bones are involved in the process, in which abscesses form. Pathological examination reveals premature fatty transformation of the thymus, granulomas in the internal organs, consisting of monocytes, neutrophilic leukocytes, followed by purulent fusion and scarring. At the same time, macrophages and neutrophils are loaded with GAGs and lipids; these cells are found in the lungs, thymus, spleen, lymph nodes, and liver. Hepato-splenomegaly is noted.
Common variable immunodeficiency. This heterogeneous group can be congenital or acquired, sporadic or familial (with a variable mode of inheritance). Characteristically - hypogammaglobulinemia, a defect in all classes of antibodies, but sometimes only IgG. In these patients, the content of B-lymphocytes in the blood and lymphoid tissue is not disturbed, but B-lymphocytes do not transform into plasma cells, there is no secretion of antibodies. Clinically - recurrent bacterial infections, enteroviral infections, herpes, giardiasis. Histologically - hyperplasia of B-cell zones of l \ follicles, l \ y, spleen. They have a high incidence of rheumatoid arthritis: pernicious and hemolytic anemia.

^ Isolated IgA deficiency. Characterized by low levels of serum and secretory IgA. This deficiency can be both familial and acquired after toxoplasmosis, measles and other viral infections. With IgA deficiency, mucosal protection is impaired and respiratory tract infections, gastrointestinal tract infections, MPS, respiratory tract allergies and autoimmune diseases (SLE, rheumatoid arthritis) develop. The bottom line is a defect in the differentiation of B-lymphocytes producing IgA. They often develop anaphylactic reactions.

cosiness. Plasma cells are not affected and the level of immunoglobulins is unchanged. This syndrome is caused by violations of embryogenesis at the 8th week of pregnancy.
^ THYMUS HYPOPLASIA

Hypoplasia - characterized by the presence of all structural elements in the thymus (reticuloepithelium, lymphocytes), but their further development does not occur, which is accompanied by a decrease in the mass of the thymus.

^ Hypoplasia of the thymus is characteristic of and immunodeficiency with thrombocytopenia and eczema (Wiskott-Aldrich syndrome) has a recessive inheritance path and is associated with the X chromosome. Characterized by thrombocytopenia, eczema, recurrent infections, early death occurs. Morphologically, the thymus is of a normal structure, but there is a progressive secondary depletion of T-lymphocytes in the peripheral blood and paracortical (thymus-dependent) l\y zones with a decrease in cellular immunity. Serum IgM level is low, IgG is normal. The level of IgA and E increases. Malignant lymphomas often develop.

Genetic deficiency of the complement system - congenital deficiency of C1, C2, C4 increases the risk of developing immunocomplex diseases (SLE).
THYMOMEGALY

TM - an increase in organ mass by 3-4 times compared with the norm, the absence of stereotypical phase changes (including III-IV phases of AT) under conditions of stress or antigenic exposure. From a clinical standpoint, TM is diagnosed radiologically based on an increase in cardiothymic-thoracic index > 0.38. TM is observed in children with frequent ARVI (4-6 times a year), with infectious-allergic myocarditis, rheumatism, cardiomyopathy, meningococcemia, bronchial asthma. These children are more likely to have rickets, congenital heart defects and the central nervous system. In infectious diseases in children with TM, death occurs in the early stages of the disease. The following HMs are microscopically distinguished:

1. 
   In the cortical zone, the proliferation of macrophages and lymphoblasts is determined (the first phase of AT) - a picture of the "starry sky", thymic bodies are few, small, mostly cellular (consisting of 3-5 ring-shaped reticuloepithelial cells), localized in the medulla. This variant occurs in children who died from acute respiratory viral infections and meningococcemia in the early stages from the moment of illness.
2. 
   In the cortical zone of the thymus, there are large clusters consisting of lymphocytes, resembling lymphoid follicles, Hassall's bodies are small, either of a cellular structure, or homogeneous-eosinophilic with preserved reticuloepithelial cells, located on the periphery. They are observed in rheumatism, infectious-allergic myocarditis, bronchial asthma, cardiomyopathy, subacute and chronic allergic reactions.
3. 
   In the thymus lobules, the division into zones is preserved, but the cortical zone prevails over the brain. Thymic bodies are small, few, cellular structure. It is observed in infectious-allergic myocarditis, acute respiratory viral infections, complicated by pneumonia, in combination with heart and central nervous system defects.

With this syndrome, embryonic cells are affected in utero, from which the parathyroid glands and thymus develop. As a result, the parathyroid glands and thymus are either underdeveloped or completely absent in the child. The tissues from which the face is formed are also affected. This is expressed by underdevelopment of the lower jaw, a short upper lip, characteristic palpebral fissures, low position and deformation of the auricles. In addition, children have congenital disorders of the heart and large vessels. The disease appears sporadically, but there are suggestions that it is genetically determined and inherited in an autosomal recessive manner.

Clinically, DiGeorge syndrome manifests itself already at birth. Disproportions of the face, heart defects are characteristic. The most characteristic symptom in the neonatal period is hypocalcemic convulsions (due to underdevelopment of the parathyroid glands). Immunodeficiency syndrome develops more often in the second half of the life of an infant and is clinically manifested by frequently recurring infections caused by viruses, fungi and opportunistic bacteria, up to severe septic processes. Depending on the degree of underdevelopment of the thymus gland, the symptoms of immune deficiency can be very different (from severe to mild), and therefore, in mild cases, they speak of partial DiGeorge syndrome. In the blood, a reduced level of calcium and an increased level of phosphorus and a decrease or complete absence of parathyroid hormone are found, which confirms the underdevelopment or absence of the parathyroid glands.

The child, being in the womb, is completely protected from any adverse environmental factors.

The thymus gland in newborns becomes the first cascade of immune defense. Which protects the child from numerous pathogenic microorganisms. The thymus in children begins to work immediately after birth, when an unfamiliar microorganism enters with the first breath of air.

The thymus gland in children under one year old manages to collect information on almost all pathogenic organisms that we encounter throughout life.

Embryology (development of the thymus in the prenatal period)

The thymus in the fetus is laid already at the seventh - eighth week of development. Even during pregnancy, the thymus gland begins to produce immune cells, by the twelfth week, the precursors of future lymphocytes, thymocytes, are already found in it. By the time of birth, the thymus in newborns is fully formed and functionally active.

Anatomy

To understand, you should attach three fingers to the top of the handle of the sternum (the area between the collarbones). This will be the projection of the thymus gland.

At birth, her weight is 15-45 grams. The size of the thymus in children is normally 4-5 centimeters in length, 3-4 centimeters in width. An intact gland in a healthy child is not palpable.

Age features

The thymus plays a key role in the development of immunity and continues to grow until puberty. At this point, the mass reaches 40 grams. The field of puberty begins reverse development (involution). By old age, the thymus gland is completely replaced by adipose tissue, its mass decreases to 6 grams. In every period of life.

The role of the thymus

The thymus produces hormones necessary for the normal development of the immune system. Thanks to them, the cells of the immune system learn to recognize harmful microorganisms and trigger mechanisms to eliminate them.

Thymus disorders

According to the degree of activity, hypofunction and hyperfunction of the thymus gland are distinguished. According to the morphological structure: (absence), (underdevelopment) and (increase in size).

Congenital pathology of the development of the thymus gland

With anomalies in the genetic code, the laying of the thymus can be disturbed even in the early embryonic period. Such a pathology is always combined with a violation of the development of other organs. There are several genetic abnormalities that cause changes that are fatal to the immune system. The body loses the ability to fight infection and is not viable.

With genetic developmental defects, the entire immune system suffers. Even with the preservation of partial activity, thymic hypoplasia in newborns leads to a persistent deficiency in the content of immune cells in the blood and persistent infections, against which there is a general developmental delay.

Also, genetic malformations include congenital cysts, thymic hyperplasia and thymomas (benign or malignant tumors of the thymus).

Hypofunction and hyperfunction of the thymus

Functional activity does not always depend on the size of the gland itself. With a thymoma or a cyst, the thymus gland is enlarged, and its activity may be normal or reduced.

Thymus hypoplasia

In the absence of a developmental anomaly, thymus hypoplasia in newborns is extremely rare. This is not an independent disease, but a consequence of a severe infection or prolonged starvation. After the cause is eliminated, its dimensions are quickly restored.

Thymus hyperplasia

There are endogenous hyperplasia, when an increase in the thymus is associated with the performance of its functions (primary) and exogenous, then the growth is caused by pathological processes in other organs and tissues.

Why does the thymus gland increase in a baby?

Causes of primary (endogenous) thymomegaly:

Causes of exogenous thymomegaly:

• Generalized disorders of the immune system(, autoimmune diseases).
• Violations of the regulatory systems in the brain(hypothalamic syndrome).

Symptoms of hyperplasia

During an external examination, an enlarged thymus gland in an infant is visible when crying, when increased intrathoracic pressure pushes the thymus above the sternum handle.

Enlargement of the thymus gland in children affects the appearance of the child - enlarged facial features, pale skin. There is a delay in general development. Enlargement of the thymus in a 2-year-old child, found during examination, especially with an asthenic physique, should not cause concern. The thymus is a fairly large organ for such a baby and may simply not fit in the space allotted to it.

Enlargement of the thymus gland in infants with transient jaundice of newborns is also not a pathology.

Of clinical importance is the simultaneous detection of several signs characteristic of diseases of the thymus:

• syndrome of compression of nearby organs;
• immunodeficiency syndrome;
• lymphoproliferative syndrome;
• disruption of the endocrine system.

Syndrome of compression of nearby organs

Enlargement of the thymus gland in children causes symptoms of compression of nearby organs. With pressure on the trachea, shortness of breath, breathing noises, dry cough appear. By squeezing the lumen of the vessels, the thymus disrupts the inflow and outflow of blood, pallor of the skin and swelling of the jugular veins are noted.

If an enlarged thymus in a child causes compression of the vagus nerve, which innervates the heart and digestive tract, a persistent slowing of the heartbeat, swallowing disorders, belching, and vomiting are noted. It is possible to change the tone of the voice.

Immunodeficiency Syndrome

When the thymus gland is enlarged in a child against the background of its dysfunction, even the usual diseases proceed differently. Any catarrhal disease can begin without an increase in temperature, with a sharp jump on the third or fourth day. Such children get sick longer than their peers, and the severity of the disease is higher. Often, the infection passes into the lower parts of the respiratory system with the development of bronchitis and tracheitis.

Lymphoproliferative syndrome

An increase in the production of hormones in the gland causes hyperstimulation of the entire immune system. Lymph nodes are enlarged, the ratio of immune cells with a predominance of lymphocytes is disturbed in the general blood test. Any external irritant causes an excessive protective reaction in the form of allergic reactions. A severe reaction to vaccination may occur.

Disruption of the endocrine system

An increase in the thymus in children can lead to malfunctions of the endocrine system, with the development of diabetes mellitus and disruption of the thyroid gland.

What is the danger of an increase in the thymus gland in a child

An increase in the thymus gland in infants, with compression of the trigeminal, disrupts the peristalsis of the esophagus and intestines. The child may have difficulty getting food and spitting air after feeding. When the trachea is compressed, more effort is required to inhale, and the increased pressure causes the alveoli in the lungs to rupture with the development of atelectasis.

Diagnostics

With symptoms of an enlarged thymus gland in a child, consultation of several specialists is necessary - an immunologist, an endocrinologist and a pediatrician. It often turns out that an increase in the thymus gland in an infant is not associated with pathology, but is due to individual anatomical features. Often parents panic that the thymus gland is enlarged in a newborn, because when crying, it often protrudes above the handle of the sternum. It is also not worth fearing inflammation of the thymus gland in infants; a huge number of immune cells in it leaves no chance for the development of infection.

To confirm the diagnosis, it is necessary to undergo a thorough examination, including:

• General and detailed blood test.
• Chest x-ray.
• Ultrasound diagnostics.

A blood test can detect a decrease in the level of T-lymphocytes, an imbalance between immunoglobulins.

X-ray of the thymus to the child will allow to exclude anomalies in the structure and location of the thymus gland.

Ultrasound allows you to accurately determine the degree of thymus hyperplasia in newborns. Examination of the adrenal glands, abdominal organs will exclude concomitant pathology.

You may need additional tests for hormone levels.

Content

People don't know everything about their body. Where the heart, stomach, brain and liver are located is known to many, and the location of the pituitary gland, hypothalamus or thymus is not known to many. However, the thymus or thymus gland is a central organ and is located in the very center of the sternum.

Thymus gland - what is it

Iron got its name due to the shape resembling a two-pronged fork. However, a healthy thymus looks like this, and a sick one takes on the appearance of a sail or a butterfly. For its proximity to the thyroid gland, doctors used to call it the thymus gland. What is thymus? This is the main organ of vertebrate immunity, in which the production, development and training of T-cells of the immune system takes place. The gland begins to grow in a newborn baby before the age of 10, and after the 18th birthday it gradually decreases. The thymus is one of the main organs for the formation and activity of the immune system.

Where is the thymus located

The thymus can be identified by placing two folded fingers on the top of the sternum below the clavicular notch. The location of the thymus is the same in children and adults, but the anatomy of the organ has age-related features. At the time of birth, the mass of the thymus organ of the immune system is 12 grams, and by puberty it reaches 35-40 g. Atrophy begins at about 15-16 years. By the age of 25, the thymus weighs about 25 grams, and by 60 it weighs less than 15 grams.

By the age of 80, the weight of the thymus gland is only 6 grams. The thymus by this time becomes elongated, the lower and lateral parts of the organ atrophy, which are replaced by adipose tissue. This phenomenon is not explained by official science. Today it is the biggest mystery of biology. It is believed that opening this veil will allow people to challenge the aging process.

The structure of the thymus

We have already found out where the thymus is located. The structure of the thymus gland will be considered separately. This small-sized organ has a pinkish-gray color, soft texture, and a lobed structure. The two lobes of the thymus are completely fused or closely adjacent to each other. The upper part of the body is wide, and the lower one is narrower. The entire thymus gland is covered with a capsule of connective tissue, under which there are dividing T-lymphoblasts. The jumpers that depart from it divide the thymus into lobules.

The blood supply to the lobular surface of the gland comes from the internal mammary artery, thymic branches of the aorta, branches of the thyroid arteries and the brachiocephalic trunk. Venous outflow of blood is carried out through the internal thoracic arteries and branches of the brachiocephalic veins. In the tissues of the thymus, the growth of various blood cells occurs. The lobular structure of the organ contains cortex and medulla. The first looks like a dark substance and is located on the periphery. Also, the cortical substance of the thymus gland contains:

• hematopoietic cells of the lymphoid series, where T-lymphocytes mature;
• hematopoietic macrophage series, which contain dendritic cells, interdigitating cells, typical macrophages;
• epithelial cells;
• supporting cells that form the hemato-thymic barrier, which form the tissue framework;
• stellate cells - secreting hormones that regulate the development of T-cells;
• baby-sitter cells in which lymphocytes develop.

In addition, the thymus secretes the following substances into the bloodstream:

• thymic humoral factor;
• insulin-like growth factor-1 (IGF-1);
• thymopoietin;
• thymosin;
• thymalin.

What is responsible for

Thymus in a child forms all the systems of the body, and in an adult it maintains good immunity. What is the thymus responsible for in the human body? The thymus gland performs three important functions: lymphopoietic, endocrine, immunoregulatory. It produces T-lymphocytes, which are the main regulators of the immune system, that is, the thymus kills aggressive cells. In addition to this function, it filters the blood, monitors the outflow of lymph. If any failure occurs in the work of the organ, then this leads to the formation of oncological and autoimmune pathologies.

In children

In a child, the formation of the thymus begins at the sixth week of pregnancy. The thymus gland in children under one year old is responsible for the production of T-lymphocytes by the bone marrow, which protect the child's body from bacteria, infections, and viruses. An enlarged goiter (hyperfunction) in a child does not affect health in the best way, as it leads to a decrease in immunity. Children with this diagnosis are susceptible to various allergic manifestations, viral and infectious diseases.

In adults

The thymus gland begins to involute with age, so it is important to maintain its functions in a timely manner. Thymus rejuvenation is possible with a low-calorie diet, taking Ghrelin, and using other methods. The thymus gland in adults is involved in modeling two types of immunity: a cell-type response and a humoral response. The first forms the rejection of foreign elements, and the second manifests itself in the production of antibodies.

Hormones and functions

The main polypeptides produced by the thymus gland are thymalin, thymopoietin, thymosin. By their nature, they are proteins. When lymphoid tissue develops, lymphocytes get the opportunity to take part in immunological processes. Thymus hormones and their functions have a regulatory effect on all physiological processes in the human body:

• reduce cardiac output and heart rate;
• slow down the work of the central nervous system;
• replenish energy reserves;
• accelerate the breakdown of glucose;
• increase the growth of cells and skeletal tissue due to increased protein synthesis;
• improve the functioning of the pituitary gland, thyroid gland;
• produce the exchange of vitamins, fats, carbohydrates, proteins, minerals.

Hormones

Under the influence of thymosin, lymphocytes are formed in the thymus, then, with the help of the influence of thymopoietin, blood cells partially change their structure to ensure maximum protection of the body. Timulin activates T-helpers and T-killers, increases the intensity of phagocytosis, accelerates regeneration processes. Thymus hormones are involved in the work of the adrenal glands and genital organs. Estrogens activate the production of polypeptides, while progesterone and androgens inhibit the process. A glucocorticoid, which is produced by the adrenal cortex, has a similar effect.

Functions

In the tissues of the goiter, blood cells proliferate, which enhances the immune response of the body. The resulting T-lymphocytes enter the lymph, then colonize in the spleen and lymph nodes. Under stressful influences (hypothermia, starvation, severe trauma, and others), the functions of the thymus gland weaken due to the massive death of T-lymphocytes. After that, they undergo positive selection, then negative selection of lymphocytes, then regenerate. The functions of the thymus begin to fade by the age of 18, and fade almost completely by the age of 30.

Thymus gland diseases

As practice shows, diseases of the thymus are rare, but always accompanied by characteristic symptoms. The main manifestations include severe weakness, an increase in lymph nodes, a decrease in the protective functions of the body. Under the influence of developing diseases of the thymus, lymphoid tissue grows, tumors are formed that cause swelling of the limbs, compression of the trachea, borderline sympathetic trunk or vagus nerve. Malfunctions in the work of the body are manifested with a decrease in function (hypofunction) or with an increase in the work of the thymus (hyperfunction).

magnification

If the ultrasound photo showed that the central organ of lymphopoiesis is enlarged, then the patient has thymus hyperfunction. Pathology leads to the formation of autoimmune diseases (lupus erythematosus, rheumatoid arthritis, scleroderma, myasthenia gravis). Hyperplasia of the thymus in infants is manifested in the following symptoms:

• decrease in muscle tone;
• frequent regurgitation;
• weight problems;
• heart rhythm failures;
• pale skin;
• profuse sweating;
• enlarged adenoids, lymph nodes, tonsils.

hypoplasia

The central organ of human lymphopoiesis may have congenital or primary aplasia (hypofunction), which is characterized by the absence or weak development of the thymic parenchyma. Combined immunological deficiency is diagnosed as a congenital disease of Dee George, in which children have heart defects, convulsions, anomalies of the facial skeleton. Hypofunction or hypoplasia of the thymus gland can develop against the background of diabetes mellitus, viral diseases, or alcohol consumption by a woman during pregnancy.

Tumor

Thymomas (tumors of the thymus) occur at any age, but more often such pathologies affect people from 40 to 60 years old. The causes of the disease have not been established, but it is believed that a malignant tumor of the thymus arises from epithelial cells. It is noticed that this phenomenon occurs if a person suffered from chronic inflammation or viral infections or was exposed to ionizing radiation. Depending on which cells are involved in the pathological process, the following types of tumors of the goiter gland are distinguished:

• spindle cell;
• granulomatous;
• epidermoid;
• lymphoepithelial.

Symptoms of thymus disease

When the work of the thymus changes, an adult feels a violation of breathing, heaviness in the eyelids, muscle fatigue. The first signs of thymus disease are a long recovery after the simplest infectious diseases. In violation of cellular immunity, symptoms of a developing disease begin to appear, for example, multiple sclerosis, Basedow's disease. With any decrease in immunity and the corresponding signs, you should immediately contact the doctor.

Thymus gland - how to check

If a child has frequent colds that turn into severe pathologies, there is a greater predisposition to allergic processes, or lymph nodes are enlarged, then a diagnosis of the thymus gland is needed. For this purpose, a sensitive high-resolution ultrasound machine is needed, since the thymus is located near the pulmonary trunk and atrium, and is closed by the sternum.

In case of suspicion of hyperplasia or aplasia, after a histological examination, the doctor may refer you to computed tomography and examination by an endocrinologist. The tomograph will help to establish the following pathologies of the thymus gland:

• MEDAC syndrome;
• DiGeorge syndrome;
• myasthenia gravis;
• thymoma;
• T-cell lymphoma;
• pre-T-lymphoblastic tumor;
• neuroendocrine tumor.

Norms

In a newborn baby, the size of the thymus gland is on average 3 cm wide, 4 cm long and 2 cm thick. The average size of the thymus is normally presented in the table:

Pathology of the thymus

In violation of immunogenesis, changes in the gland are observed, which are represented by such diseases as dysplasia, aplasia, accidental involution, atrophy, hyperplasia with lymphoid follicles, thymomegaly. Often, thymus pathology is associated either with an endocrine disorder, or with the presence of an autoimmune or oncological disease. The most common cause of a decline in cellular immunity is age-related involution, in which there is a deficiency of melatonin in the pineal gland.

How to treat the thymus

As a rule, thymus pathologies are observed up to 6 years. Then they disappear or turn into more serious diseases. If the child has an enlarged goiter gland, then a phthisiatrician, immunologist, pediatrician, endocrinologist and otolaryngologist should be observed. Parents should monitor the prevention of respiratory diseases. If symptoms such as bradycardia, weakness and/or apathy are present, urgent medical attention is required. Treatment of the thymus gland in children and adults is carried out by medical or surgical methods.

Medical treatment

When the immune system is weakened, to maintain the body, it requires the introduction of biologically active substances. These are the so-called immunomodulators that thymus therapy offers. Treatment of the goiter gland in most cases is carried out on an outpatient basis and consists of 15-20 injections that are injected into the gluteal muscle. The treatment regimen for thymus pathologies may vary, depending on the clinical picture. In the presence of chronic diseases, therapy can be carried out for 2-3 months, 2 injections per week.

Intramuscularly or subcutaneously, 5 ml of thymus extract isolated from the peptides of the goiter gland of animals is injected. It is a natural biological raw material without preservatives and additives. Already after 2 weeks, improvements in the general condition of the patient are noticeable, since protective blood cells are activated during the treatment. Thymus therapy has a long-term effect on the body after the therapy. A second course can be carried out after 4-6 months.

Operation

Thymectomy or removal of the thymus is indicated if the gland has a tumor (thymoma). The operation is performed under general anesthesia, which keeps the patient asleep during the entire operation. There are three types of thymectomy:

1. Transsternal. An incision is made in the skin, after which the sternum is separated. The thymus is separated from the tissues and removed. The incision is closed with staples or sutures.
2. Transcervical. An incision is made along the lower part of the neck, after which the gland is removed.
3. Video assisted surgery. Several small incisions are made in the upper mediastinum. A camera is inserted through one of them, displaying the image on the monitor in the operating room. During the operation, robotic arms are used, which are inserted into the incisions.

diet therapy

Diet therapy plays an important role in the treatment of thymus pathologies. Foods rich in vitamin D should be introduced into the diet: egg yolk, brewer's yeast, dairy products, fish oil. The use of walnut, beef, liver is recommended. When developing a diet, doctors advise including in the diet:

• parsley;
• broccoli, cauliflower;
• oranges, lemons;
• sea ​​buckthorn;
• syrup or decoction of wild rose.

Alternative treatment

Children's doctor Komarovsky advises to warm up the thymus with a special massage to increase immunity. If an adult has an unreduced gland, then he should maintain immunity for prevention by taking herbal preparations with rose hips, black currants, raspberries, and lingonberries. Treatment of the thymus with folk remedies is not recommended, since the pathology requires strict medical supervision.

Video

Attention! The information presented in the article is for informational purposes only. The materials of the article do not call for self-treatment. Only a qualified doctor can make a diagnosis and give recommendations for treatment based on the individual characteristics of a particular patient.

Page 5 of 17

From atrophic (involutive) changes in the thymus, one should distinguish congenital malformations of its development, manifested either by its complete absence - aplasia, agenesis, or underdevelopment with a violation of the formation of lymphocytes in it - hypoplasia, alymphoplasia.
Congenital absence of the thymus may be the only malformation or be combined with other malformations, in particular with congenital absence of the parathyroid glands, which is described in the Anglo-American literature under the name of the Digeorge syndrome (Dodson et al., 1969; Kirkpatrick, Digeorgie, 1969; Lobdell, 1969 ). Although cases of detection of the complete absence of the thymus gland in children who died in early infancy have been known for a long time (Bischoff, 1842; Friedleben, 1858), until recently the death of such children was not associated with the absence of the thymus gland in them.
With hypoplasia, the thymus gland lags behind in its development from the very beginning and at the birth of a child it turns out to be small, often not exceeding 1-2 g in weight. Microscopically, its lobules also turn out to be reduced in size, and due to the almost complete absence of lymphocytes, their division into the cortical and medulla layers are not observed. Usually there are no Hassall's little bodies in them.
Changes that characterize hypoplasia of the thymus gland have only recently been studied in connection with the description of Glanzmann and Riniker in 1950 of a peculiar disease in infants, which they called essential lymphocytophysis. Due to the fact that this disease often has a family character, it was later also described under the names of family (family) lymphophenia (Tobbler, Cottier, 1958) or hereditary lymphoplasmacytic dysgenesis (Hitzig, Willi, 1961).
The disease is manifested by persistent, untreated diarrhea, leading children to exhaustion and death. In this case, there is a sharp lymphopenia and hypogammaglobulinemia in the blood, and at the autopsy of the dead, a sharp decrease in the size of the spleen and lymph nodes is found with an almost complete absence of lymphocytes in them. Initially, due attention was not paid to the state of the thymus, although already at the first description of the disease, Glanzmann and Riniker (1950) mention that in one of the two children examined by them, the thymus was small and edematous. However, later changes in the thymus in this disease were studied in more detail (Cottier, 1958; Blackburn, Gordon, 1967; Thompson, 1967; Berry, 1968; Berry, Thompson, 1968), which gave reason to consider the entire disease as a manifestation of primary immunological deficiency. due to hypoplasia or aplasia of the thymus (Good, Martinez, Gabrielsen, 1964; Sell, 1968).
With aplasia or hypoplasia of the thymus, the normal development of the entire lymphoid tissue is disrupted, and therefore the body remains incapable of immunological reactions. As a result, the normal flora of the intestine begins to have a pathogenic effect, causing damage to it and thereby diarrhea, leading to: exhaustion. Often, a secondary infection in the form of candidiasis (Glanzmann, Riniker, 1950; Thompson, 1967), pneumocystis pneumonia (Becroft, Douglas, 1968; Berg, Johansson, 1967), etc., joins. With homotransplantation of skin and other tissues in such patients no rejection reaction occurs (Rosen, Gitlin, Janeway, 1962; Dooren, Bekkum, Cleton, 1968). Thus, the whole picture of the disease is fully consistent with the so-called wasting syndrome that develops in animals after the removal of their thymus gland, produced immediately after birth (Miller, 1961; Good et al., 1962; Metcalf, 1966; Hess, 1968). In some cases, in children with hypoplasia of the thymus, shortly before death, the phenomena of aplastic anemia were also noted (Glanzmann, Riniker, 1950; Thompson, 1967; Dooren et al., 1968) or granulo- and thrombocytopenia (Lamvik, Moe, 1969) .
Most children with aplasia or hypoplasia of the thymus die within the first 6 months of life. However, in some cases, a longer course of the disease is also observed - up to 1 year 7 months (Hitzig, Biro et al., 1958) and more. A more detailed immunological examination of such patients made it possible to detect in some of them the preservation of the ability to some extent to some immunological (allergic) reactions (Hitzig, Biro et al., 1958), as well as the preservation of certain fractions of immunoglobulins (Becroft, Douglas, 1968; Berg, Johansson, 1967), which makes it possible to distinguish a number of clinical varieties of this disease (Sell, 1968). Obviously, this depends on the degree of hypoplasia (alimphoplasia) of the thymus gland, which can be expressed differently. With a relatively small degree of hypoplasia due to the partial preservation of the body's ability to immune reactions, the disease can take a protracted course. An example of this, apparently, is the observation of Grote and Fischer-Wasels (1929) of “total alymphocytosis” in a 39-year-old man who died of exhaustion. At autopsy, atrophy of the spleen (18.0) and other lymphoid organs was found in him. The small intestine had dark-pigmented scars, and the mesenteric lymph nodes contained foci of "cheesy necrosis". The thymus gland, unfortunately, was not examined. In the same respect, one of our observations, which is given below, is of undoubted interest.
Male E., 55 years old. A carpenter. Married, had no children. From early childhood, he often had diarrhea, in connection with which he strictly followed a diet throughout his life. Smoked a little. He rarely drank alcohol. Over the past 3 years, he was comprehensively examined in many hospitals in Leningrad, but the diagnosis remained unclear. In connection with the growing exhaustion and suspicion of a tumor in the abdominal cavity, on 17/V, 1968, he was placed in the clinic of faculty surgery of the Military Medical Academy, where on 31/V he underwent a diagnostic laparotomy, during which no tumor was found. After the operation, the patient's condition began to deteriorate rapidly. Blood test 17/VI 1968: Er. 3700000, Hb 13.2 g%, bloom, po. 1.0, l. 13500, of which s. 45%, p. 37%, y. 7%, lymph. eleven%. ROE 10 mm/h. In previous blood tests, the number of lymphocytes fluctuated between 7-14%. During repeated bacteriological studies of feces, pathogenic flora was not detected. The patient died on June 17, 1968 with symptoms of increasing exhaustion and associated pneumonia. He was delivered for autopsy with a diagnosis of a severe form of sprue disease with extreme malnutrition and severe beriberi, condition after diagnostic laparotomy, ascites, sacral bedsores, bilateral pneumonia and pulmonary edema.
At autopsy (prosector T, V. Polozova) there was a sharp exhaustion. Body weight 40 kg with a height of 166 cm. On the midline of the abdomen, a fresh postoperative scar. In the area of ​​the sacrum there is a bedsore with a dark gray bottom 5x4 cm. The left pleural cavity is free. The right lung in the upper sections is fused with the parietal pleura. In the region of its apex there are several dense scars and a small encapsulated calcified focus. In the lower part of the left lung, there are multiple gray-red airless foci of compaction measuring 1-1.5 cm in diameter. Inferior branch of the right pulmonary artery thrombosis. In the lower lobe of the right lung under the pleura, a black-red airless focus of irregular wedge-shaped shape, 5X5X4 cm in size, is determined. The broio-chopulmonary lymph nodes are not enlarged, black-gray, with small gray scars. There is a small amount of clear yellowish fluid in the abdominal cavity. On the mucous membrane of the small intestine, transverse superficial ulcers up to 4x2 cm in size with a dark gray pigmented bottom are visible. Two of the same type of ulcer are present in the mucous membrane of the caecum. Peyer's patches and lymphatic follicles are not defined. Lymph nodes of the mesentery up to 1 cm in diameter, in many of them yellowish-gray areas are visible on the cut. The spleen weighs 30.0 with a thickened capsule, dark red in section. Tonsils are small. Inguinal and axillary lymph nodes up to 1 cm in size, gray in section. The heart weighs 250.0, its muscle is brown-red. Liver weighing 1500.0, brown-brown in section. There were multiple small hemorrhages under the pleura of the left lung and in the folds of the gastric mucosa. Other organs and tissues were somewhat reduced in size, otherwise unchanged. The thymus gland is not found in the tissue of the anterior mediastinum.

The results of histological examination.

Small intestine: superficial ulcers with necrotic bottom containing gram-negative rods; in the submucosal and muscular layers - infiltrates of histiocytes and a few lymphocytes. Mesenteric lymph nodes: foci of necrosis are visible among the lymphoid tissue, without cellular reaction around; tubercle bacilli and other microbes are not found in them; an axillary lymph node with sclerosis in the center and a small amount of lymphoid tissue along the periphery (Fig. 10, a). Spleen: lymphatic follicles are very weak, found in small numbers; the pulp is sharply plethoric. Fiber of the anterior mediastinum: among the fatty tissue, there are a few small lobules of the thymus gland, which do not have a division into cortical and medulla layers and do not contain Hassall's bodies; lymphocytes in the lobules are almost completely absent (Fig. 10, b, a), the lobules consist of reticular and epithelial cells, forming separate glandular cells in places. Liver: fatty degeneration and brown atrophy. Myocardium: brown atrophy. Kidney: hydropic dystrophy. Lung: foci of pneumonia containing gram-positive cocci.
Based on the results of the autopsy and histological examination, a diagnosis of chronic nonspecific ulcerative enterocolitis was made, which led to exhaustion and was complicated by pneumonia. The development of the disease in this case can be associated with the inferior development of the thymus gland and the entire lymphatic apparatus as a whole.
Rice. 10. Alymphoplasia of the thymus.
a-axillary lymph node with sclerosis of the central part and preservation of lymphoid tissue in the form of a narrow layer along the periphery (magnification 60X) ”b- one of the lobules of the thymus gland with an almost complete absence of lymphocytes (magnification 120X); in the same way (sw. 400X) ..
Recently, transplantation of the thymus from human fetuses has been used with some success for the treatment of such patients (August et al., 1968; Clevelend et al., 1968; Dooren et al., 1968; Good et al., 1969; Koning and others, 1969). At the same time, after transplantation, there is a rapid increase in the number of lymphocytes in the blood, the appearance of immunoglobulins in it. Children have the ability to cellular and humoral immune responses, including the rejection of tissue homotransplants (August et al., 1968; Koning et al., 1969). When examining a biopsied lymph node in one of these patients after thymus transplantation, it was found to have well-defined lymphatic follicles with breeding centers (Clevelend, Fogel, Brown, Kay, 1968).

Medical and social expertise and disability in thymus hypoplasia

THYM GLAND APLASIA (hypoplasia) (Dee George's syndrome) - congenital underdevelopment of the thymus gland as a result of a violation of the normal embryogenesis of the thymus, accompanied by a violation of the formation of neighboring organs - the parathyroid glands, aorta and other developmental anomalies, which is clinically manifested by primary immunodeficiency and hypoparathyroidism.

Epidemiology: the frequency in children has not been established, however, the frequency of all defects in T-cell immunity is 5-10% in the structure of primary immunodeficiencies, and the total frequency of primary forms of immunodeficiency is 2:1000.

Etiology and pathogenesis. The disease is associated with impaired intrauterine development of the fetus for a period of about 8 weeks; under the influence of a teratogenic factor, the laying of organs developing during this period from the 3rd-4th pharyngeal fissures is disrupted: the thymus, parathyroid glands, aorta, as well as the facial skull, the central nervous system. In 80-90% of children with this syndrome, a deletion of the 22nd chromosome is detected (partial monosomy on the 22nd chromosome - a deficiency of genetic material), combined with a symptom complex: congenital heart defects, "cleft palate" and other defects of the facial skeleton, thymus hypoplasia and hypocalcemia due to hypolalasia of the parathyroid glands.

clinical picture.
From birth, the child has hypocalcemia syndrome (typical hypocalcemic convulsions), recurrent oral candidiasis with transformation into chronic candidiasis of the skin and mucous membranes, anomaly of the aorta (its arch is turned to the right), sepsis. There may be a congenital heart disease with a corresponding clinical picture, an anomaly of the facial skull; in the future - a decrease in mental abilities, delayed sexual development.

Complications: HF, impaired mental development of varying severity, damage to internal organs by Candida fungi (candidal bronchitis, esophagitis with subsequent development of esophageal stricture).

Laboratory and instrumental methods confirming the diagnosis:
1) study of the content of parathyroid hormone in the blood;
2) biochemical analysis of blood (decrease in calcium in the blood);
3) ECG, EchoCG;
4) consultation of a psychologist, neurologist, psychiatrist;
5) mycological examination;
6) immunogram (decrease in the number and function of T-lymphocytes).

Treatment: compensation of insufficiency of the thyroid glands with vitamin D preparations, transplantation of the fetal thymus gland, the use of thymus hormones for replacement purposes, bone marrow transplantation, correction of congenital heart disease, the use of antimycotic agents for the treatment of candidiasis.

The prognosis is relatively favorable - children are viable, do not suffer from viral and bacterial infections, but have chronic candidiasis of the skin and mucous membranes with damage to internal organs, and need constant treatment with antimycotic drugs; hypoparathyroidism also requires constant replacement therapy with vitamin D preparations; in addition, children lag behind in mental development.

Disability criteria: mental retardation, requiring the child to study in a special school, NC from 1-2st. and higher with congenital heart disease, recurrent candidiasis of the bronchi, esophagus and other internal organs with a violation of their functions.

Rehabilitation: medical rehabilitation during periods of exacerbations; social, psychological, pedagogical and professional habilitation during the remission of the disease.

Description:

Thymus aplasia is a group of diseases caused by genetic defects in the immune system.

Symptoms:

1. Di-George syndrome. Along with aplasia of the gland, aplasia of the parathyroid glands with manifestations is possible. In pathogenesis, there is a deficiency of circulating T-lymphocytes, a sharp inhibition of the reaction of cellular immunity, a relative increase in the number of B-lymphocytes and the preservation of the reaction of humoral immunity (normal level of immunoglobulins in the blood).
Characteristic signs of the disease are, starting from the neonatal period, recurrent infections of the respiratory and digestive systems. It is usually combined with anomalies in the development of the aortic arch, lower jaw, earlobes, with hypoplasia of the lymph nodes and underdevelopment of thymus-dependent zones.

2. Nezelof's syndrome - autosomal recessive aplasia of the thymus with lymphopenia, without aplasia of the parathyroid glands, but with underdevelopment of thymus-dependent zones in the lymph nodes and spleen.
A sharp decrease in the reactivity of T-lymphocytes (deficiency of the cellular immune system) is also revealed.
From the neonatal period, recurrent bronchitis, enterocolitis of viral or fungal etiology, herpetic eruptions, are noted. Deficiency of T-lymphocytes and inhibition of the reaction of cellular immunity are more pronounced than in DiGeorge's syndrome. Patients die at an early age.

3. Louis-Bar syndrome - immunological deficiency with -telangiectasia, characterized by autosomal recessive inheritance of aplasia of the gland, occurs with a decrease in lymphocytes in the thymus-dependent zones of the lymph nodes and the spleen, demyelination in the cerebellum.
Multisystem Complex Disorders:
1) neurological (ataxia, impaired coordination, etc.);
2) vascular (telaniectasia of the skin and conjunctiva);
3) mental (mental retardation);
4) endocrine (impaired functions of the adrenal glands, gonads). Recurrent sino-pulmonary infections appear from early childhood.
Violation of cellular immunity is accompanied by damage to the T- and B-systems of immunity, deficiency of IgA. In the blood serum, emorional fir-trees (α- and β-fetoproteins) are found. In such patients, malignant neoplasms (more often, lymphogranulomatosis) develop more often.

4. "Swiss syndrome" - autosomal recessive severe combined immunological deficiency. Lymphopenic agammaglobulinemia, aplasia or hypoplasia of the thymus are combined with hypoplasia of the entire lymphoid tissue. Sharp hypoplasia of the thymus gland, hypoplasia of the lymph nodes and lymphoid formations of the spleen, intestines.
Since the neonatal period, recurrent fungal, viral and bacterial lesions of the skin and mucous membranes of the nasopharynx, respiratory tract, and intestines. In these children, the thymus gland is difficult to identify.
Along with a sharp inhibition of reactions of cellular immunity, a deficiency of humoral immunity (deficiency of T- and B-lymphocytes) is revealed. Children usually die in the first six months of life.

Causes of occurrence:

This group of diseases is caused by genetic defects in the immune system.
Congenital, or primary, aplasia (or hypoplasia) of the thymus gland is characterized by the complete absence of the thymic parenchyma or its extremely weak development, which determines the presence of severe combined immunological deficiency due to a sharp decrease in the content of T- and B-lymphocytes and the absence of thymus bodies.
All these diseases are accompanied by recurrent inflammatory diseases, often of pulmonary or intestinal localization, which are often the direct cause of death of patients. Therefore, children, especially young children, suffering from recurrent inflammatory diseases, should be carefully examined for the functional state of the thymus.
Similar changes are found in children with a number of diseases united in the immunodeficiency group. The most pronounced defects in the development of the thymus were found in the following syndromes.

Treatment:

- a genetic disease belonging to the group of primary immunodeficiencies and, along with weakened immunity, characterized by numerous malformations. Symptoms of this condition are frequent bacterial infections with a tendency to severe course, congenital heart defects, facial abnormalities and other disorders. Diagnosis of DiGeorge syndrome is based on the study of the heart, thyroid and parathyroid glands, the study of the immunological status and the data of molecular genetic analyzes. Treatment is only symptomatic, including surgical correction of heart defects and facial anomalies, immunological replacement therapy, and the fight against bacterial and fungal infections.

General information

DiGeorge syndrome (hypoplasia of the thymus and parathyroid glands, velocardiofacial syndrome) is a genetic disease caused by a violation of the embryonic development of the third and fourth pharyngeal sacs. This condition was first described in 1965 by the American pediatrician Angelo Di Giorgi, who classified it as congenital aplasia of the thymus and parathyroid glands. Further research in the field of genetics helped to determine that the disorders in this disease go far beyond the primary immunodeficiency. This gave rise to another name for the DiGeorge syndrome. Given the most commonly affected organs (palate, heart, face), some experts call this pathology velocardiofacial syndrome. A number of modern researchers distinguish between these two conditions and believe that the "true" velocardiofacial syndrome is not accompanied by severe immunological disorders. The incidence of DiGeorge syndrome is 1:3,000-20,000 - such a significant discrepancy in the data is due to the fact that a reliable and clear boundary between this disease and velocardiofacial syndrome has not yet been established. Therefore, the same patient, according to different experts, may have either a primary immunodeficiency, accompanied by concomitant disorders, or more numerous malformations against the background of a decrease in immunity.

Causes of DiGeorge Syndrome

The genetic nature of DiGeorge syndrome is damage to the central part of the long arm of chromosome 22, where genes encoding a number of important transcription factors are presumably located. One of these genes, TBX1, was identified; its expression product is a protein called T-box. It belongs to the family of proteins that control the processes of embryogenesis. Evidence of the relationship between DiGeorge syndrome and TBX1 is the fact that a small percentage of patients do not have pronounced damage to the 22nd chromosome, only mutations in this gene are present. There are also suggestions about the role of deletions of other chromosomes in the development of this disease. So, manifestations similar to the DiGeorge syndrome were detected in the presence of damage to the 10th, 17th and 18th chromosomes.

In most cases of DiGeorge syndrome, the deletion of the 22nd chromosome captures about 2-3 million base pairs. Most often, this genetic defect occurs spontaneously during the formation of male or female germ cells - that is, it is germinal in nature. Only a tenth of all cases of the disease is a familial form with an autosomal dominant pattern of inheritance. The pathogenesis of the DiGeorge syndrome is reduced to a violation of the formation of special embryonic formations - the pharyngeal sacs (mainly the 3rd and 4th), which are the precursors of a number of tissues and organs. They are mainly responsible for the formation of the palate, parathyroid glands, thymus, mediastinal vessels and the heart, therefore, with DiGeorge's syndrome, malformations of these organs occur.

Symptoms of DiGeorge Syndrome

Many manifestations of the DiGeorge syndrome are determined immediately after the birth of a child, individual malformations (for example, of the heart) can be detected even earlier - on preventive ultrasound examinations. Most often, anomalies in the development of the face are the first to be detected - a splitting of the palate, sometimes in combination with a “cleft lip”, prognathism of the lower jaw. Often, babies with DiGeorge syndrome have a small mouth, a small nose with an enlarged bridge of the nose, and deformed or underdeveloped cartilages of the auricles. With a relatively mild course of the disease, all of the above symptoms can be expressed rather weakly, even splitting of the hard palate can occur only in its back part and be detected only with a thorough examination by an otolaryngologist.

In the first months of life of a patient with DiGeorge syndrome, manifestations of congenital heart defects come to the fore - it can be both Fallot's tetrad and individual disorders: ventricular septal defect, cleft ductus arteriosus and a number of others. They are accompanied by cyanosis, cardiovascular insufficiency and, in the absence of qualified medical care (including surgical care), can lead to early death of patients. Seizures and tetany due to parathyroid hypoplasia and subsequent hypocalcemia are considered to be another common disorder in children with DiGeorge syndrome.

The next most important manifestation of DiGeorge syndrome, which distinguishes it from other varieties of velocardiofacial syndrome, is a pronounced primary immunodeficiency. It develops due to aplasia or underdevelopment of the thymus and therefore affects cellular immunity to a greater extent. However, due to the close relationship between the humoral and cellular sections of the immune system, this leads to a general weakening of the body's defenses. Patients with DiGeorge syndrome are extremely sensitive to viral, fungal and bacterial infections, which often take a protracted and severe course. Some researchers note the presence of mental retardation of varying degrees, sometimes there may be seizures of neurological origin.

Diagnosis of DiGeorge Syndrome

To determine the DiGeorge syndrome, the method of a physical general examination, cardiological studies (EchoCG, electrocardiogram), ultrasound of the thyroid gland and thymus, and immunological tests are used. A supporting role is played by the conduct of general and biochemical blood tests, the study of the patient's history, genetic studies. When examining patients with DiGeorge syndrome, disorders characteristic of the disease can be determined - splitting of the hard palate, anomalies in the structure of the face, pathology of the ENT organs. In the anamnesis, as a rule, frequent episodes of viral and fungal infections that take a severe course are detected, convulsions caused by hypocalcemia, and extensive carious lesions of the teeth are often detected.

On ultrasound examinations of the thymus, there is a significant decrease in mass or even the complete absence of the organ (agenesis). Echocardiography and other cardiac diagnostic methods reveal numerous heart defects (for example, ventricular septal defect) and mediastinal vessels. Immunological studies confirm a significant drop in the level of T-lymphocytes. The same phenomenon is observed in peripheral blood and is often combined with a decrease in the concentration of immunoglobulin proteins. Biochemical study of blood indicates a decrease in the level of calcium and parathyroid hormones. A geneticist can search for deletions on chromosome 22 using fluorescent DNA hybridization or multiplex polymerase chain reaction.

Treatment of DiGeorge Syndrome

There is currently no specific treatment for DiGeorge syndrome, only palliative and symptomatic techniques are used. It is very important to identify congenital heart defects as early as possible and, if necessary, to perform their surgical correction, since it is cardiovascular disorders that are the most common cause of neonatal death in this disease. A significant danger is convulsive seizures caused by hypocalcemia, which requires timely correction of the electrolyte balance of blood plasma. The help of surgeons with DiGeorge syndrome may also be required to eliminate malformations of the face and palate.

Due to severe immunodeficiency, any signs of a bacterial, viral or fungal infection are a reason for the urgent use of appropriate drugs (antibiotics, antiviral and fungicidal agents). To improve the immune status of a patient with DiGeorge syndrome, a replacement infusion of immunoglobulins obtained from donor plasma can be performed. In some cases, the thymus gland was transplanted, which stimulated the formation of its own T-lymphocytes - this contributed to an improvement in the quality of life of patients.

Forecast and prevention of DiGeorge's syndrome

The prognosis of DiGeorge syndrome is assessed by most researchers as uncertain, since this disease is characterized by a significant variability in symptoms. In severe cases, there is a high risk of early neonatal death due to a combination of cardiovascular and immunological disorders. More benign forms of DiGeorge syndrome require fairly intensive palliative care, it is especially important to pay attention to the treatment and prevention of viral and fungal infections. The intellectual development of patients is somewhat slowed down, however, with the correct pedagogical and psychological correction, the manifestations of developmental delay can be leveled. Due to the frequent spontaneous nature of mutations, the prevention of DiGeorge syndrome has not been developed.

The child, being in the womb, is completely protected from any adverse environmental factors.

The thymus gland in newborns becomes the first cascade of immune defense. Which protects the child from numerous pathogenic microorganisms. The thymus in children begins to work immediately after birth, when an unfamiliar microorganism enters with the first breath of air.

The thymus gland in children under one year old manages to collect information on almost all pathogenic organisms that we encounter throughout life.

Embryology (development of the thymus in the prenatal period)

The thymus in the fetus is laid already at the seventh - eighth week of development. Even during pregnancy, the thymus gland begins to produce immune cells, by the twelfth week, the precursors of future lymphocytes, thymocytes, are already found in it. By the time of birth, the thymus in newborns is fully formed and functionally active.

Anatomy

To understand, you should attach three fingers to the top of the handle of the sternum (the area between the collarbones). This will be the projection of the thymus gland.

At birth, her weight is 15-45 grams. The size of the thymus in children is normally 4-5 centimeters in length, 3-4 centimeters in width. An intact gland in a healthy child is not palpable.

Age features

The thymus plays a key role in the development of immunity and continues to grow until puberty. At this point, the mass reaches 40 grams. The field of puberty begins reverse development (involution). By old age, the thymus gland is completely replaced by adipose tissue, its mass decreases to 6 grams. In every period of life.

The role of the thymus

The thymus produces hormones necessary for the normal development of the immune system. Thanks to them, the cells of the immune system learn to recognize harmful microorganisms and trigger mechanisms to eliminate them.

Thymus disorders

According to the degree of activity, hypofunction and hyperfunction of the thymus gland are distinguished. According to the morphological structure: (absence), (underdevelopment) and (increase in size).

Congenital pathology of the development of the thymus gland

With anomalies in the genetic code, the laying of the thymus can be disturbed even in the early embryonic period. Such a pathology is always combined with a violation of the development of other organs. There are several genetic abnormalities that cause changes that are fatal to the immune system. The body loses the ability to fight infection and is not viable.

With genetic developmental defects, the entire immune system suffers. Even with the preservation of partial activity, thymic hypoplasia in newborns leads to a persistent deficiency in the content of immune cells in the blood and persistent infections, against which there is a general developmental delay.

Also, genetic malformations include congenital cysts, thymic hyperplasia and thymomas (benign or malignant tumors of the thymus).

Hypofunction and hyperfunction of the thymus

Functional activity does not always depend on the size of the gland itself. With a thymoma or a cyst, the thymus gland is enlarged, and its activity may be normal or reduced.

Thymus hypoplasia

In the absence of a developmental anomaly, thymus hypoplasia in newborns is extremely rare. This is not an independent disease, but a consequence of a severe infection or prolonged starvation. After the cause is eliminated, its dimensions are quickly restored.

Thymus hyperplasia

There are endogenous hyperplasia, when an increase in the thymus is associated with the performance of its functions (primary) and exogenous, then the growth is caused by pathological processes in other organs and tissues.

Why does the thymus gland increase in a baby?

Causes of primary (endogenous) thymomegaly:

Causes of exogenous thymomegaly:

• Generalized disorders of the immune system(, autoimmune diseases).
• Violations of the regulatory systems in the brain(hypothalamic syndrome).

Symptoms of hyperplasia

During an external examination, an enlarged thymus gland in an infant is visible when crying, when increased intrathoracic pressure pushes the thymus above the sternum handle.

Enlargement of the thymus gland in children affects the appearance of the child - enlarged facial features, pale skin. There is a delay in general development. Enlargement of the thymus in a 2-year-old child, found during examination, especially with an asthenic physique, should not cause concern. The thymus is a fairly large organ for such a baby and may simply not fit in the space allotted to it.

Enlargement of the thymus gland in infants with transient jaundice of newborns is also not a pathology.

Of clinical importance is the simultaneous detection of several signs characteristic of diseases of the thymus:

• syndrome of compression of nearby organs;
• immunodeficiency syndrome;
• lymphoproliferative syndrome;
• disruption of the endocrine system.

Syndrome of compression of nearby organs

Enlargement of the thymus gland in children causes symptoms of compression of nearby organs. With pressure on the trachea, shortness of breath, breathing noises, dry cough appear. By squeezing the lumen of the vessels, the thymus disrupts the inflow and outflow of blood, pallor of the skin and swelling of the jugular veins are noted.

If an enlarged thymus in a child causes compression of the vagus nerve, which innervates the heart and digestive tract, a persistent slowing of the heartbeat, swallowing disorders, belching, and vomiting are noted. It is possible to change the tone of the voice.

Immunodeficiency Syndrome

When the thymus gland is enlarged in a child against the background of its dysfunction, even the usual diseases proceed differently. Any catarrhal disease can begin without an increase in temperature, with a sharp jump on the third or fourth day. Such children get sick longer than their peers, and the severity of the disease is higher. Often, the infection passes into the lower parts of the respiratory system with the development of bronchitis and tracheitis.

Lymphoproliferative syndrome

An increase in the production of hormones in the gland causes hyperstimulation of the entire immune system. Lymph nodes are enlarged, the ratio of immune cells with a predominance of lymphocytes is disturbed in the general blood test. Any external irritant causes an excessive protective reaction in the form of allergic reactions. A severe reaction to vaccination may occur.

Disruption of the endocrine system

An increase in the thymus in children can lead to malfunctions of the endocrine system, with the development of diabetes mellitus and disruption of the thyroid gland.

What is the danger of an increase in the thymus gland in a child

An increase in the thymus gland in infants, with compression of the trigeminal, disrupts the peristalsis of the esophagus and intestines. The child may have difficulty getting food and spitting air after feeding. When the trachea is compressed, more effort is required to inhale, and the increased pressure causes the alveoli in the lungs to rupture with the development of atelectasis.

Diagnostics

With symptoms of an enlarged thymus gland in a child, consultation of several specialists is necessary - an immunologist, an endocrinologist and a pediatrician. It often turns out that an increase in the thymus gland in an infant is not associated with pathology, but is due to individual anatomical features. Often parents panic that the thymus gland is enlarged in a newborn, because when crying, it often protrudes above the handle of the sternum. It is also not worth fearing inflammation of the thymus gland in infants; a huge number of immune cells in it leaves no chance for the development of infection.

To confirm the diagnosis, it is necessary to undergo a thorough examination, including:

• General and detailed blood test.
• Chest x-ray.
• Ultrasound diagnostics.

A blood test can detect a decrease in the level of T-lymphocytes, an imbalance between immunoglobulins.

X-ray of the thymus to the child will allow to exclude anomalies in the structure and location of the thymus gland.

Ultrasound allows you to accurately determine the degree of thymus hyperplasia in newborns. Examination of the adrenal glands, abdominal organs will exclude concomitant pathology.

You may need additional tests for hormone levels.

This is a very severe pathology, which is manifested by a child lagging behind in height and weight, a decrease in all life processes, the development of convulsive syndrome, intestinal dysbacteriosis, and the addition of various infections. Mortality in these children is very high if intensive treatment is not started in a timely manner.

What diagnostic methods are used?

A modern method for examining the thymus gland in children is ultrasound scanning. It is not associated with radiation and can be safely performed any number of times, for example, to monitor treatment. New Doppler ultrasound technologies of the thymus gland in children allow obtaining the most accurate data on the size, location and structure of the gland.

A laboratory test is mandatory: a clinical blood test, immunological tests, determination of the amount of protein and trace elements (electrolytes). In case of congenital pathology, genetic studies are carried out.

How is cancer treated in children?

Treatment of the thymus gland in children depends on the degree of change in its size, the state of immunity, the general condition and age of the child, the presence of concomitant diseases. In general, the treatment algorithm is as follows:

1. Normalization of the diet (sufficient amount of protein and vitamins).
2. Daily routine with sufficient physical activity and good rest.
3. Hardening, sports, physical education.
4. Taking natural immunostimulants.
5. Mandatory intake of antihistamines during a cold, with the development of allergic reactions.

Important! Aspirin is contraindicated for children with thymus hyperplasia, it contributes to increased growth of the gland and the development of aspirin asthma.

In severe cases of thymus hyperplasia in children, hormone therapy is prescribed (Prednisolone, Hydrocortisone, Cortef).

If the thymus gland is excessively enlarged in a child, according to indications, an operation is performed - resection of the gland (thymectomy). After removal of the thymus, the child is under dispensary observation for several years.

A child with thymus hyperplasia must be carefully protected from colds and infections, avoid being in groups, crowded places. Routine vaccination is carried out as usual, while taking into account the condition of the child so that he does not have a cold, allergy, diathesis and other diseases at that moment.

The thymus gland plays an important role in maintaining the health status of young children. Therefore, frequently ill children need to be examined and, if necessary, treated.

Thymic Hypoplasia (Digeorge Syndrome)

Hypoplasia or aplasia of the thymus, parathyroid glands and anomalies of other structures are formed at the same time (for example, heart defects, renal pathologies, anomalies of the facial skull, including the cleft palate, etc.) and are caused by a deletion in chromosome 22 q11.

Involvement in the process > 2 of the following organs of the system:

• thymus;
• parathyroid gland;
• the cardiovascular system.

Transient hypocalcemia may occur, causing convulsions in neonates.

Serum immunoglobulins are usually within normal limits but may be lower, especially IgA; IgE levels may be higher than normal.

The number of T-cells is reduced and the percentage of B-cells is relatively increased. The ratio of helpers and suppressors is normal.

With the full expression of the syndrome, patients are usually susceptible to opportunistic infections (Pneumocystisjiroveci, fungi, viruses), and death is possible due to blood transfusion due to graft versus host disease. In partial syndrome (with variable hypoplasia), development and response to infection may be adequate.

The thymus is often absent; with ectopic thymus, histology is normal.

The follicles of the lymph nodes are normal, but areas of cellular depletion are observed in the paracortical and thymus-dependent zones. The risk of developing cancer and autoimmune diseases is not increased.

Thymus tumors

More than 40% of thymus tumors are accompanied by parathymic syndromes that develop later and in a third of cases are multiple.

Associated

Myasthenia gravis in about 35% of cases, and in 5% of cases it may appear on the 6th year after thymoma excision. Thymoma develops in 15% of patients with myasthenia gravis.

Acquired hypogammaglobulinemia. 7-13% of adult patients have an associated thymoma; after thymectomy, the condition does not improve.

True red cell aplasia (RCC) is found in approximately 5% of patients with thymoma.

50% of cases of ICCA are associated with thymoma, in 25% improvement occurs after thymectomy. Thymoma may occur simultaneously or develop later, but not precede granulocytopenia or thrombocytopenia, or both in / 3 cases; thymectomy in this case is useless. ICCA occurs in 1/3 of patients with hypogammaglobulinemia and thymoma.

The child has constant colds with characteristic symptoms (cough, runny nose, chills, sore throat), and doctors make the same diagnosis - SARS?

In fact, everything is correct, but let's look deep into the problem. Colds very often occur against the background of a suppressed immune system of the body.

Thymus in childhood is just the same and is one of the main reasons for the weakening of the immune system. And this needs to be dealt with in time in order to prevent the situation from worsening.

In this article, we will talk about what the thymus gland is, what it is responsible for, how parents should react when the first symptoms of problems with the thymus appear, and whether this disease can be stopped.

A bit of theory

According to doctors, the thymus gland is one of the most important organs in the body. It protects people from many diseases and fights against foreign microorganisms.

But let's take a closer look at the mechanism of action of the thymus and consider the principle of its structure in the body of a child.

What is it and what is it responsible for

Thymus (thymus, goiter) is a V-shaped organ in the human chest cavity, responsible for preventing autoimmune diseases.

The word "thymus" in Greek means "life force". Most often, problems with the thymus gland are observed precisely in childhood.

There are a lot of reasons for this, and doctors still do not know the exact answer to the question: why does the child have an enlarged thymus gland.

Some information suggests that the causes of impaired functioning of the thymus gland are: negative external influences (radiation background, poor ecology, etc.), genetic predispositions, various disorders in the mother's body during, nephropathy, acute infectious diseases of the mother during wearing child.

Did you know? American scientists have come to the conclusion that AIDS can be overcome. To do this, you need to learn how to stimulate the production of T-hellers in the thymus.

The thymus begins its active growth from the first day of birth. At this point, its weight is only 15 grams. Growth continues until full puberty, and at the age of 15-16 this organ reaches a weight of 30-40 g.

From this point on, growth is gaining a reverse course, and the thymus gland is gradually decreasing. By 70 years of human life, it weighs no more than 7 g.

The thymus gland has a lobulated structure. Inside it, B-lymphocytes and T-lymphocytes are stored, which are responsible for protecting the body from foreign cells.

The thymus is the central and most important organ of the body's immune system. Its inhibition activity leads to an increased risk of developing cancer.

Sometimes the wrong mechanism of action of the thymus leads to the fact that its T-lymphocytes begin to fight with the normal cells of their own body.

In any case, the thymus is an important component of any child's body, and it must be treated in a timely manner in case of any pathological disorders.

The role of the thymus gland in the human body was discovered quite recently, namely in 1961 in Australia. Then a scientist named D. Miller conducted tests on newborn rats.

During the tests, he removed the thymus glands and observed the reaction of the animal organism (in particular, to the reaction of organ transplantation).

As a result: suppressed production of antibodies (T-lymphocytes) and complete rejection by the body of any transplanted organs.

The conclusion from this is this: the thymus contributes to the development and further training of protective lymphocytes. In addition, it does not allow lymphocytes to attack their own body (unless, of course, a tumor develops in this body).

Where is

Often questions about where the thymus gland is located baffle even adults. The thymus is located in the chest cavity.

If this organ develops at a normal pace and during its development no pathological changes are observed in the baby's body, then it is projected 10-15 mm above the handle of the sternum.

Its lower end can reach 3 or 4 ribs. In cases where the child has an increase in the thymus gland, then its lower end can reach the 5th rib.

How is the diagnosis

To date, the most popular and accurate method for diagnosing the thymus is x-ray examination. It is carried out only in cases where ultrasound does not provide a clear enough understanding of the state of the thymus gland.

With an increase in the main organ of the immune system, a characteristic triangular or oval ribbon-like shadow appears on the pictures. Doctors, using the J. Gewolb method, can determine the degree of thymus enlargement (there are 3 in total).

Important! To stimulate the thymus, it is necessary to regularly carry out thermal procedures (visit baths, saunas, etc.).

That is, the researcher calculates the ratio of the size of the thymus to the total volume of the chest. In more complex situations, it is advisable to use pulsed or multiaxial radiography, tomography, or pneumomediastinography.

Despite such a wide range of possibilities of modern diagnostics, radiographic methods are not always effective, since the output is often insufficiently accurate results.

In most medical institutions in Russia, Ukraine, Belarus, Moldova, the main diagnostic method for examining the thymus is ultrasound.

If you bring your child to a local clinic, then, first of all (perhaps after palpation), the doctors will send him for an ultrasound examination.

Diagnosis of the thymus using ultrasound in children of different age categories is as follows:

• newborns and children under 9 months of age are often laid on a couch with their heads thrown back. Then an ultrasound procedure is performed;
• children aged 9 to 18-20 months are examined in the "sitting" position;
• starting from the age of two, the ultrasound procedure can be performed in the “standing” position.

Many parents do not know what an ultrasound of the thymus in children is, how the procedure goes, and why it is needed at all.

In fact, in this particular case, ultrasound (ultrasound) will help determine the condition of the thymus gland in a child (whether further treatment is required, or the change is minor and does not require therapeutic interventions).

Did you know? Scientists have created« injection of youth» , which will make the body of an adult feel a new and powerful surge of strength. This procedure involves the introduction of stem cells into the thymus. According to experts, such an injection will rejuvenate the thymus, and, accordingly, the aging body.

The sensor is installed parallel to the sternum and the handle. Previously, a special gel-like consistency is applied to the sternum.

After the ultrasound procedure, doctors determine the volume of the thymus according to the data obtained (length, width and height), then calculate the mass of the organ based on a pre-calculated volume and special coefficients that are standardized in the medical literature.

When the mass of the thymus gland is known, doctors can make an appropriate diagnosis for the child.

Norms and deviations

After the studies of the thymus gland, doctors make a diagnosis based on the data obtained.

Often, serious disorders of this tiny organ are not observed, and even the most common increase in the thymus (thymomegaly) is not a dangerous disease. Particularly acute cases (hyperplasia or hypoplasia), fortunately, are extremely rare.

Normal performance

It doesn’t matter which diagnostic method was used to study the thymus (ultrasound, radiography, etc.), it all comes down to calculating the total volume and weight of this organ.

Based on these data, a specific diagnosis is made. Normal indicators of the size of the thymus for a newborn baby are: length - 41 mm, width - 33 mm, thickness - 21 mm, total volume - 13900 mm³.

It should be clarified that the given data are reference, and slight deviations in one direction or another are allowed. According to experienced specialists, in the normal state, the weight of the thymus should be 0.3% of the total body weight of the child.

For allowable weight of the thymus in the range of 15 to 45 g, for adolescents - from 25 to 30 g. In other cases, doctors diagnose: thymomegaly.

Enlargement (thymomegaly)

Thymomegaly, in most cases, is a hereditary disease and is observed in children under 6 years of age. The incidence of thymomegaly in children under 3 years old is 13-34%, in children from 3 to 6 years old - 3-12%.

After 6 years, this disease is rare. However, otherwise, such children are included in the risk group for the development of autoimmune and oncological diseases.

Important!Thymus growth slows down only after reaching 12 years of age.

Researchers in the field of biology and medicine distinguish two forms of thymomegaly: acquired and congenital.

The first of them can develop against the background of external influences or past pathological changes and diseases (Addison's disease, adrenal oncology, pneumonia, SARS, vasculitis).

Congenital thymomegaly implies a properly formed thymus, which is larger than the allowable size. Such a defect in almost all cases does not pose a threat to the life and health of the child.

Thymomegaly can be of three degrees of severity. They differ according to the indicators of CTTI (cardiothymic-thoracic index).

An indicator of CTTI up to 0.33 indicates that the baby is completely healthy, an indicator in the range from 0.33 to 0.37 indicates that the child has developed the first degree of thymomegaly.

Indicators for establishing a diagnosis of thymomegaly of the second degree should be within 0.37 - 0.42, of the third degree - over 0.42.

Hyperplasia and hypoplasia of the thymus

Hyperplasia is an acute disease of the thymus gland. Against its background, cells in the brain and cortex begin to actively grow with the simultaneous formation of new formations in the thymus.

In this disease, unlike thymomegaly, the size of the thymus can remain normal, but the structural and functional components are disturbed.

An ultrasound examination is not suitable for an accurate diagnosis. In this case, an X-ray examination is performed, followed by determination of the nature of the shadow of the thymus gland.

The main causes of hyperplasia are considered to be:

• oncology;
• anemia and cardiovascular disease;
• autoimmune and endocrine diseases.

Thymus hypoplasia or DiGeorge syndrome, in most cases, occurs in the case of intrauterine infection of the fetus. As a result, in a newborn child, the thymus gland is underdeveloped or absent altogether.

With hypoplasia, the child has lesions of the facial tissue and general disturbances in the structure of the facial organs.

In addition, the child has disorders in the structure of the heart and kidneys. Some scientists also tend to suggest that there is a genetic predisposition to DiGeorge syndrome.

Did you know?If the thymus gland is completely removed after the age of five, then this will not affect the quality of his life in any way. The fact is that in the first five years the thymus manages to produce such a number of T-lymphocytes that will protect the human body until old age.

In any case, with an underdeveloped thymus, the symptoms of hypoplasia may themselves disappear after the age of six.

However, all this time the child may be susceptible to infectious diseases, not tolerate the processes of blood transfusion and organ transplantation.

Is it worth worrying

An unambiguous answer to the question of whether it is worth treating the thymus can only be given by an experienced specialist after a thorough diagnosis of this tiny organ.

Symptoms that do not require additional help

It should be noted that for any symptoms of any, it is better to consult a doctor for advice. Let him say that your child is healthy, and agree that this will be enough for you to have peace of mind.

World experts in the field of immunology say that a slightly enlarged thymus gland in newborns is the norm. The increase with age returns to normal and all symptoms disappear.

However, in infancy, the following symptoms may appear, which do not have serious consequences:

• slightly enlarged lymph nodes;
• slight enlargement of the tonsils and;
• the child's weight is slightly increased.

When to See a Doctor

There are a number of symptoms of impaired functionality or changes in the size of the thymus.

It is in such cases that it is necessary to visit a pediatrician in a short time, and then an immunologist:

• sudden jumps in body weight of the baby;
• a venous network is formed on the chest (marble pattern);
• frequent regurgitation after feeding;
• the occurrence of coughing in a horizontal position;
• a strong increase in the size of the lymph nodes and tonsils;
• the frequency of ARVI diseases increases several times;
• during the crying of the child, his skin acquires a purple hue;
• depressed muscle tone;
• violation of the heart rhythm;
• hyperhidrosis;
• the child constantly freezes the endings of the arms and legs;
• anomalies in the development of the joints;
• hypotension;
• cryptorchidism, phimosis, hypoplasia;
• pallor (due to anemia, which manifests itself as a result of a lack of iron macronutrients in the body);
• sweating and prolonged subfebrile temperature.

In more acute cases, with a strong increase in the thymus (with CTTI values ​​over 0.42), the child may swell the cervical veins, develop shortness of breath, cyanosis. This happens due to the compression of vital organs by the thymus gland.

How is the treatment

With thymomegaly 1 and 2 degrees, doctors allow vaccinations, but only under strict supervision. In addition, the health status of a small patient is periodically assessed.

Vaccination for thymomegaly grade 3 is prohibited, since the immune system of the baby's body does not work properly and will not be able to normally reject even small amounts of foreign organisms.

In some specific cases, the pediatrician consults with an endocrinologist and an immunologist, after which he gives the go-ahead for vaccination (for example, the polio vaccine).

Important!Sound sleep and prolonged exposure to fresh air contribute to a speedy recovery from thymomegaly.

Treatment of a child is carried out only in acute cases, when problems with the thymus gland can affect other organs and systems of the body.

Treatment is of various characters, and is prescribed only by specialists of medical institutions after appropriate diagnosis.

Below are the main points in the treatment of problems with the thymus.

Did you know?Light tapping with your fingertips at the location of the thymus will give you a boost of energy for the whole day.

As a rule, the symptoms of problems with the thymus disappear when the child reaches 3-6 years of age.

Sometimes thymomegaly can pass into other diseases, and in order to prevent this, at the first symptoms of the disease, you should immediately consult a doctor.

Prevention

To date, the mechanisms for the development of this syndrome are unknown, so preventive measures cannot give a high result.

It is known that thymomegaly in children can develop against the background of an incorrect lifestyle of a pregnant mother. Therefore, preventive measures can be considered a healthy lifestyle for women.

Preventive measures for an enlarged thymus gland in infants and older children are aimed at avoiding stressful situations, regular exercise (for older children).

Finally, I would like to note that parents should not be afraid of thymomegaly in children under 3 years old. Earlier we gave some statistics, and according to them, about every fourth child in our country has problems with the thymus gland.

The main thing in this matter: a timely visit to a doctor and targeted treatment (if such a need exists).

Home " Planning » Hypoplasia of the thymus. Thymus: the thymus gland in children