Increased LDH 1. LDH in the blood - what is it, the reasons for the increase in the biochemical blood test. Changes in LDH levels in the bloodstream

Lactate dehydrogenase molecule

Lactate dehydrogenase (LDH) is a zinc-containing enzyme involved in a very common biochemical reaction in the body: the conversion of L-lactate to pyruvate and vice versa. The latter is necessary to start a cascade of reactions that result in the formation of ATP (energy molecules), carbon dioxide and metabolites necessary to build new biological molecules (amino acids, carbohydrates, fatty acids, heme).

LDH is present in any organs and tissues, but is found in the greatest amount in skeletal muscle cells, cardiac muscles, liver, kidneys, lymphatic vessels, blood cells: erythrocytes and platelets. Therefore, in order to obtain pure serum LDH values, it is worth making sure that the blood is taken correctly, that there is no hemolysis (massive destruction of blood cells) in it, due to which LDH of erythrocytes will also enter the serum.

The enzyme has its isoforms

Thanks to electrophoresis, different isoforms of LDH were isolated, which are indicated by the numbers 1-5, which is convenient for identifying the enzyme's belonging to certain tissues. For example, it is noted that the LDH-1 isoform is characteristic of tissues with a high aerobic metabolism - the heart muscle, kidneys, brain, while LDH-5 is more common in skeletal muscles and the liver. Moreover, skeletal muscles often work in anaerobic, airless conditions, as a result of which lactate is formed from pyruvate, which is metabolized in the liver, heart and other tissues.

Based on all of the above, two main functions of LDH can be distinguished:

1. biochemical function. Participation in a wide range of metabolic transformations at the cellular level, which provides the body with energy and molecules for building cells.
2. diagnostic function. Determining the concentrations of LDH, both different isoforms and the total amount, helps in the diagnosis of pathologies of various organs.

Enzyme levels in the blood

LDH in women is often slightly lower than in men, but the indicators should be within the normal range.

Causes of an increase in LDH in the blood

Heart failure is the cause of the increase in LDH-1 and LDH-2

1. Damage to the heart muscle: acute myocardial infarction, myocarditis, congestive heart failure. At the same time, an increase in LDH-1 and / or LDH-2 is noted.
2. Liver tissue damage, often massive: hepatitis, liver cirrhosis, primary tumor, or metastasis of a tumor of another organ to the liver. An increase in LDH-4.5 is noted.
3. Damage or disease of skeletal muscles, inflammatory or degenerative, atrophic processes in them. LDH-4.5 mainly increases.
4. Blood diseases, especially those accompanied by massive cell breakdown: hemolytic anemia, B12 deficiency anemia, sickle cell anemia, acute leukemia, massive blood transfusion, pulmonary embolism, shock conditions. An increase in LDH-2,3,4 is noted.
5. Lung diseases: pneumonia, lung tumor, lung infarction.
6. Acute pancreatitis.
7. Kidney infarction.
8. Physiological causes: childhood, pregnancy, heavy and prolonged physical activity, the first time after transfusion of blood components.

Do not forget that it is not always possible to identify specific isoforms of LDH, so even a general increase in the enzyme requires a thorough study of all organs that could be involved in the pathological process.

Causes of a decrease in LDH in the blood

Some drugs can lower LDH levels

Often, low enzyme levels do not indicate a critical pathology in the body, but they can be detected in the following cases:

A consistently low LDH value in one person at various stages of his life may indicate congenital mutations that led to the synthesis of an insufficiently active enzyme.

How to Suspect Abnormalities (Signs and Symptoms)

An increase in LDH levels is not accompanied by specific signs

An increase in LDH can be suspected when diseases and conditions are detected, as a result of which human tissues and organs experience severe stress: necrotic, inflammatory, tumor processes, cell decay due to exposure to an external factor (trauma of any type, hemolysis). All this is usually manifested by general symptoms: fever, asthenia, pain. The functions of damaged organs are also violated. For example, in myocardial infarction, the heart performs its pumping function inefficiently. The rest of the organs, like the heart itself, are poorly supplied with blood, which leads to a number of complications: organ ischemia, pulmonary edema, arrhythmia, and possibly death of the patient. Damage to the liver, for example, with the development of its cirrhosis, will lead to a violation of the synthetic and neutralizing functions of the organ: encephalopathy, swelling of the extremities and abdomen, jaundice, increased bleeding, etc. will appear.

It is extremely difficult to suspect a decrease in LDH. Usually a person does not notice pronounced changes in his body. However, children often have symptoms of asthenia: apathy, lethargy, drowsiness, weakness, lack of active movements.

Despite clinical suspicions about the concentration of LDH, biochemical analysis of venous blood serum will help to most accurately identify a deviation from the norm.

Indications for research

Hemolytic anemia - an indication for research

1. Early diagnosis of myocardial infarction, as well as differential diagnosis of myocardial infarction with angina pectoris, further monitoring of the patient's condition.
2. Diagnosis of anemia, accompanied by the breakdown of red blood cells (hemolysis).
3. Oncological processes of any localization.
4. Chronic diseases of the liver, pancreas.

Study preparation

Physical rest is an important condition for preparing for analysis

Research can be carried out both on a planned and emergency basis.

It is preferable to take blood for routine analysis in the morning on an empty stomach, after an overnight fast of 8-14 hours. Drinking clean water without gas is allowed. Dinner on the evening before the study should be light, but you should not completely starve for more than 14 hours. 2-3 days before the analysis, you should limit yourself to fatty, fried, sweet foods, alcohol, and coffee. Stress and especially heavy muscle load during preparation (also 2-3 days in advance) are prohibited! Smoking in the morning before the study is not recommended. Medicines that may affect the result can only be canceled by the attending physician, and not by the patient himself. In case of pregnancy, a woman should warn the doctor about this, since a physiological increase in LDH is possible.

Emergency research is carried out at any time of the day. It is better that 3-4 hours have passed since the last meal, however, a shorter period of time should not force doctors to delay the analysis, especially if myocardial infarction is suspected.

Deciphering the results

Decryption starts from the lab

Usually, it takes about a day to receive the result of the analysis in a planned manner, and about 1-2 hours in an emergency. The primary interpretation is carried out in the laboratory indicating an increase or decrease in the level of LDH, after which the conclusion of the laboratory is interpreted by the attending physician, more often by a general practitioner, cardiologist, pediatrician, or other specialists.

The doctor needs to correlate laboratory results with the clinical picture of the disease, and then navigate with further diagnosis and treatment. For example, in case of suspected myocardial infarction (long-term compressive pain behind the sternum, not relieved by nitroglycerin), the EMS doctors who arrived on the call immediately begin the primary diagnosis (take an ECG) and primary treatment (aspirin, clopidogrel, heparin, propranolol and morphine, if necessary), however take blood for analysis. Subsequently, the patient is taken to the therapeutic or cardiology department, and the blood is transferred to the laboratory to study the level of enzymes, one of which is LDH.

In a planned manner, the doctor does not need to rush, but this does not change the order of his work: an analysis for LDH correlates with the clinic, for example, cirrhosis of the liver or a lung tumor, after which they move on to more complex diagnostic methods (ultrasound, CT, MRI) and treatment.

Enzyme Level Correction

Identification of the cause is the path to a successful correction of the indicator

It is simply impossible to correct the level of LDH without correcting the patient's condition. There are no drugs that directly reduce or increase LDH.

Only timely treatment for the identified pathology can ensure the normalization of the indicator. For example, the appointment of hepatoprotectors for hepatitis or cirrhosis of the liver will reduce damage to the cells of the organ and the release of LDH into the blood. The appointment of surgical, chemical, radiation therapy will lead to the death of the tumor tissue, after which LDH will gradually normalize. In the case of an increase in LDH due to hemolysis, hemotransfusion is necessary, that is, a transfusion of red blood cells and other blood components to the patient if necessary.

A decrease in LDH usually does not require correction.

The role of LDH in the diagnosis of myocardial infarction

LDH is one of the enzymes that respond to necrotic processes in the heart muscle. Below is a table with enzymes and their reaction time to the process.

As can be seen from the table, the very first enzyme that reacts to myocardial infarction is CPK-MB, but it returns to normal one of the first. LDH, unlike it, increases a little later, but it remains at a high level for as long as possible, which is valuable in the late diagnosis of myocardial infarction.

Of course, LDH activity depends on the size and depth of the damaged muscle focus, and the return to normal depends on the reserve of myocardial cells and the start of timely treatment.

In addition to the initial diagnosis of myocardial infarction, LDH makes it possible to distinguish from it an attack of angina pectoris, short-term ischemia of the heart muscle without the formation of necrosis. It was noted that in angina pectoris the level of LDH is normal, which is explained by the preservation of the integrity of myocardial cells.

Lactate dehydrogenase or LDH (LDG) is a zinc-containing enzyme found inside the cell.

Its main functions are the transformation of lactic acid into pyruvic acid (pyruvate), and its important function is to prevent the reverse reaction of the previous process.

The concentration of this enzyme is noted in all tissue formations of the human body. The tissues of the liver, heart, skeletal muscles, kidneys, as well as erythrocytes have the highest concentration.

In the latter, it is presented in the form of five isozymes, which are numbered from one to five, respectively.

In a healthy state of the body, the value of LDH does not accumulate. This enzyme is excreted from the body in the same amount as it is formed. The value of lactate dehydrogenase does not indicate the development of pathological conditions of the body. It determines the consequences of the disease - the deformation of cells and tissues in the human body.

LDH in the blood, what is it?

A laboratory blood test for LDH is an additional diagnostic method. The analysis is not the main one for diagnosing diseases, and is used to confirm or refute the diagnosed individual diseases.

The information content of the analysis allows you to determine the effectiveness of the applied courses of therapy, track the progression of the disease and determine its stage.

The concentration of LDH in the human body consists of five fractions of isoenzymes. They are classified based on the structure of the cell and location in different organs of the human body.

These isozymes are presented in the following fractions:

• LDH-1. The first fraction is also referred to as the HHHH tetramer and is localized, in its predominant set, in the myocardium and brain. The index of the first fraction increases significantly with the deformation of the tissues of the heart muscle;
• LDH-2. The highest concentration of this enzyme is recorded in the liver tissues and biological material;
• LDH-3. These isoforms are concentrated in the thyroid gland, lung, renal and pancreatic tissues, as well as in all smooth muscle tissues of the body;
• LDH-4. It is located, for the most part, in the same organs as the third isoenzyme, as well as in the liver tissues, placenta and reproductive system of men;

An active increase in the above three fractions occurs in pathological conditions in which platelets die in large numbers. One of the most dangerous pathological conditions leading to massive death of platelets is thrombosis of the pulmonary trunk.

• LDG-5, its characteristic is the source of the enzyme, which lies in the liver tissues, skeletal muscles, placenta and the male reproductive system. The enzyme increases significantly in the acute stages of viral hepatitis.

The distribution of different types of lactate dehydrogenase occurs depending on the types of tissues in which they accumulate. This means that different quantitative indicators of the fraction are recorded in different parts of the body.

The results are shown in the table below.

What are the normal levels of LDH?

Normal indicators for LDH of a healthy person fluctuate in women and men. In adults and children, the levels are different, and the indicators also vary by gender.

LDH rates are shown in the table below.

In newborns, lactate in the blood is always elevated. Deciphering the analysis is the business of a qualified doctor, since when analyzing the results, it is necessary to take into account the age category of the child and his physical indicators.

Also, indicators are calculated depending on physical activity. With active child sports, the level of LDH is increased, which is the norm. And for women, the indicator shows below the norm than for men.

The definition of units of measurement and indicators of the norm may vary, depending on the laboratory in which the study is carried out. .

Indications for analysis

A blood test for lactate dehydrogenase is a biochemical one, and is prescribed for suspicion of the following diseases:

• Severe forms of anemia. Such pathological conditions lead to the death of red blood cells from an insufficient amount of iron in the body. This leads to an increase in LDH;
• Suspicions of tumor formations. The biochemistry of LDH is not a means of diagnosing cancer. For this, doctors use a tumor marker;
• Death of heart tissue. The LDH compound is released into the blood during myocardial tissue necrosis;
• All pathological conditions in which any tissue of the human body dies.

Any suspicion of necrotic changes in tissues within the human body contributes to the direction of LDH for a biochemical blood test.

In addition to taking indicators of this enzyme, additional types of blood tests may be prescribed.

These include:

• Alanine aminotransferase (ALT);
• Aspartate aminotransferase (AST);
• Creatine kinase total;
• Creatine kinase MB;
• Lactate dehydrogenase 1, 2 (LDH 1, 2 fractions);
• Phosphatase alkaline total;
• Troponin I;

Preparation for analysis

After a patient has been scheduled to undergo an LDH study, some preparatory measures should be taken. They are observed in order to obtain the most accurate result, since some third-party factors can affect the composition of the blood.

The actions that must be performed in preparation for the analysis of LDH are:

• The analysis is given on an empty stomach. Eating must be stopped at least eight hours before blood donation;
• At least one day prior to blood sampling, you need to stop eating fatty, highly salty, spicy or spicy foods in the diet;
• At least 7 days (!) give up alcoholic beverages;
• Strong physical activity;
• If the patient is taking medications (vitamin C), stop taking them at least 48 hours before blood sampling. With the continuous use of drugs, you need to notify the attending physician about this, so that he takes into account all the amendments in the test results, which will contribute to accurate diagnosis;
• Avoid stressful situations, nervous breakdowns and everything that loads the nervous system.

Reasons for the increase

Provoking an increase in LDH levels in a biochemical blood test occurs under the influence of inflammatory processes, in which tissue cells are deformed and die.

Factors affecting the increase in LDH levels may be the following:

All diseases in which any body cells die will lead to an increase in LDH levels. So in such pathological conditions, their role in the diagnosis is great.

The discrepancy between the indicators to the norm may also be under the influence of physiological factors that are not associated with pathological conditions, in which the value can be increased.

These include:

• The period of bearing a child (a test for LDH is done without fail);
• The first months of a baby's life;
• Great physical activity;
• Age category;
• gender;
• The impact of certain drugs.

All these factors must be taken into account in order to correctly diagnose the disease.

Since the correct diagnosis will occur after determining the indicators of each LDH fraction, and not its general indicator.

How to lower the LDH level?

The use of actions to reduce the level of LDH is allowed only after the final diagnosis by a qualified doctor.

Determination of LDH levels is necessary in the treatment of the following diseases:

Why do LDH levels drop?

If the level of this enzyme is lowered, then it is easier to determine the cause, since this is facilitated by a small range of factors. Registration of low rates is noted in very rare cases. Doctors do not consider a decrease in LDH levels to be an indication of a pathological condition.

In most cases, the indicator is low with the use of vitamin C, or increased glucose oxidation. In the most rare cases, LDH is lowered in hereditary diseases, but such cases are rare.

LDH index and myocardial tissue death

The study of this indicator is an important diagnostic value for structural myocardial disorders. This analysis refers to the main studies of enzymes that determine the death of heart muscle tissue in the first 24 hours of myocardial progression.

The LDH level will be increased already after the first ten hours from the onset of the pain syndrome and the progression of necrotic changes in the heart muscle, first of all, the indicator of the first fraction (LDH-1) increases, and indirectly increases the second fraction.

In addition to the growth of the total indicator of lactate dehydrogenase, a special role in the death of cardiac tissues belongs to the first fraction, which is also referred to as hydroxybutyrate dehydrogenase, and the ratio between the first and second fractions.

With necrotic changes in the myocardium, the total LDH will be lowered in relation to LDH-1. With such processes, the overall level will tend to a smaller number, while the first fraction will only grow.

Changes in the indicators of the first fraction and the total indicator, similar to necrosis of the tissues of the heart, may also indicate the following diseases:

• Death of tissues in the kidneys;
• Tumor formations in the female and male reproductive systems;
• Pathological conditions accompanied by severe cell destruction;
• Megaloblastic anemia. With such a disease, the level of the first fraction is many times greater than the second;
• Various hemolytic anemias.

Diagnosis of diseases is confirmed with the help of additional hardware studies prescribed by a doctor based on the inherent symptoms and laboratory tests.

Prevention

In order for the LDH indicator to be within the normal range, it is recommended to follow preventive actions aimed at countering the progression of many diseases:

• Proper nutrition. A balanced diet is needed, with the exclusion of harmful foods, heavily fried, salty, spicy dishes. Eat more fresh vegetables and fruits, as well as lean meats and foods rich in vitamins and nutrients;
• Healthy lifestyle is an essential factor in the prevention of most diseases. Sports are recommended to maintain the tone of the body, as well as to prevent excess weight and increased cholesterol deposits;
• Stress avoidance. Limit yourself as much as possible from nervous tension, stressful influences and strong emotional stress. All of them adversely affect the general state of health;
• Take your medications regularly if your doctor has prescribed them. Failure to comply with the course of therapy can lead to the death of tissues in the body and death;
• Maintain water balance. Drink at least one and a half liters of clean water per day;
• Stop drinking alcohol and cigarettes;
• Once a year, go to the doctor for a check-up, take a blood test and fully explore the body. This will help to detect diseases at an early stage of development, which will greatly facilitate the course of therapy and the possibility of burdens.

This list of actions is aimed at preventing a large number of diseases, and will help minimize the chance of damage to the body.

Forecast for life

Since the growth of LDH levels occurs under the influence of dying tissues, the prediction depends on several factors. Namely, the extent of necrotic changes, the localization of dying tissues, the degree of damage, the presence of concomitant diseases and the effectiveness of the course of treatment.

When diagnosing deaths in the early stages and not in vital organs, the prognosis is favorable, with the appointment of effective treatment and compliance with all recommended preventive actions.

If the tissues of the heart, liver, brain, or other important organs die, the prognosis worsens significantly. The scale of death, as well as the speed and effectiveness of the prescribed treatment, play an important role here.

With extensive necrosis, death is possible. If a heart or brain infarction occurs, then the chance of death increases by 2 times.

Regularly examine the body to diagnose possible diseases in the early stages. At detection of the slightest symptoms address to the doctor, it can save your life.

Do not self-medicate and be healthy!

Many tests are used to diagnose various pathological processes. Recently, such an indicator as LDH (lactate dehydrogenase) has often been considered.

In order for an ordinary person to understand its meaning, it is necessary to understand what it is. And also find out why it is being investigated, what may be the danger of an increased or decreased level of LDH in a biochemical blood test.

Basic information

Lactate dehydrogenase belongs to the class of oxidoreductases and is an essential enzyme that is involved in the oxidation of glucose and the formation of lactic acid. Its peculiarity lies in the fact that it does not accumulate in the cells.

The enzyme undergoes complete cleavage and excretion.

The intermediary in this process is oxygen, due to which glucose is decomposed into water, energy and carbon dioxide. In the absence of oxygen, energy production is reduced by 20 times, which leads to the accumulation of lactic acid.

Unlike healthy cells, cancer cells can feed without oxygen.

Classification

LDH can be subdivided into isoenzymes that have differences in composition or are located in one specific organ.

Lactate dehydrogenase is classified into several types depending on the organs in which it is present:

• LDH-1 - in the brain and heart;
• 2 - in the blood composition (platelets and erythrocytes) and liver;
• 3 - in skeletal muscles, lungs, pancreas and thyroid gland, adrenal glands and spleen;
• 4 and 5 - in the same organs as mentioned in the previous paragraph, plus in the liver, placenta, male germ cells, granulocytes.

Depending on the type of LDH, the activity of the enzyme in the blood composition may differ slightly.

Norm for children and adults

Depending on the gender and age category, the norm of the indicator in the blood will be different.

The values ​​of the LDH level are presented in the table below.

As can be seen, in children at birth, the values ​​are higher than in adults. With age, the norm in a child decreases.

The high value in men is explained by the fact that they are more susceptible to intense physical exertion.

In women during pregnancy, the values ​​\u200b\u200bmay also exceed the norm. Before donating blood for biochemistry, it is imperative to inform the specialist about this.

When is an analysis ordered?

It is mandatory done when donating blood fluid for biochemistry. It is prescribed not only for almost any disease, but also for preventive purposes.

Close attention to this indicator is paid if there are suspicions of such pathological processes as:

1. Anemia. With the development of the disease, there is a more rapid destruction of red blood cells, which leads to an increase in LDH. Indications for analysis in this case will be the following symptoms: pallor of the skin, tinnitus, dizziness.
2. Myocardial infarction. If the heart muscle is destroyed, then the indicator has quite high values.
3. Oncological pathologies.
4. Acute or chronic tissue damage.

In addition, in some cases, determination of the amount of LDH in the fluids of other organs may be prescribed.. This is necessary in order, for example, to differentiate between viral and bacterial meningitis by studying the cerebrospinal fluid.

Reasons for the increase

LDH activity increases with almost any disease accompanied by inflammatory processes and cell death. Among the reasons for the increase in the indicator are the following:

1. Myocardial infarction in the acute phase.
2. Functional insufficiency of the vascular and cardiac systems, lungs. Failures in the work of the heart lead to circulatory disorders, the appearance of congestive symptoms and the activation of LDH 4 and 5 fractions.
3. Inflammation of the lungs, hepatic and renal parenchyma.
4. Hemolytic and pernicious anemia.
5. , pulmonary embolism.
6. Viral hepatitis in the period of exacerbation. While in the chronic form of pathology, the level of LDH does not go beyond the normal range.
7. Tumor formations of a malignant nature, in particular, with metastases, the localization of which is the liver.
8. Hematological diseases, for example, granulocytosis, anemia, the development of which was preceded by a lack of vitamin B12 or folic acid deficiency.
9. Massive platelet destruction. The main reason for this pathological condition is blood transfusion.
10. Pathologies of the musculoskeletal system. First of all, this applies to lesions of the skeletal muscles (atrophy in the initial stages, various injuries).

Determination of glycolytic enzyme is very important in the diagnosis of myocardial infarction.

Lactate dehydrogenase may also be elevated for other reasons. These include:

• megaloblastic anemia;
• conditions in which there is an increased destruction of the cellular structure (necrotic processes of an acute form);
• damage to the parenchyma of the kidneys;
• oncological formations localized in the glands of the reproductive system of men and women.

Thus, pathologies in which the cells of the renal and hepatic parenchyma, as well as erythrocytes and platelets are destroyed, are considered the main reasons for the increase in enzymes in the blood serum.

Reasons for the drop in the indicator

If LDH is low, which is extremely rare, the following factors may contribute to this:

• taking ascorbic acid, Metronidazole and other medicines for a long time;
• mutations at the gene level;
• treatment of anemia, oncological diseases, leukemia and lymphoma.

In addition, a large amount of oxalates and urea in the human body can provoke a decrease in the value, which occurs in the presence of stones in the kidneys and urinary tract.

Symptoms of high and low values

As a rule, an increase or decrease in the level of lactate dehydrogenase is not accompanied by specific symptoms. Depending on what could provoke a change in values ​​in a patient, there may be symptoms such as:

• pain in the region of the heart;
• unstable blood pressure and pulse;
• headache;
• drowsiness;
• general weakness, decreased performance;
• heat.

Required tests

To determine the concentration of LDH in the composition of the blood fluid, a biochemical analysis is carried out. Biomaterial is taken directly from a vein. However, in order for the results to be the most truthful, it is necessary to prepare well for the procedure.

Training

Before conducting a study, experts advise you to perform some simple steps that will increase its accuracy and information content. As numerous practice shows, it is not difficult to change the test results, but the consequences can be the saddest.

When inaccurate information is received, as a rule, an incorrect diagnosis is made and inadequate therapeutic measures are taken that do not bring an effective result. We can say that the preparatory stage is a mandatory procedure before analysis.

• do not eat for 12 hours before the study;
• do not smoke for at least an hour;
• avoid physical activity;
• eliminate emotional upheaval and stress.

In addition, the distortion of the results can also be caused by such pathological conditions as:

• hemodialysis;
• dermatological diseases of the skin;
• the use of medications;
• thrombocytosis;
• stress associated with physical activity.

Immediately before taking an analysis, the presence of such factors must be reported to a specialist who will decide whether to do tests or not, and also consider all possible options for error.

Holding

In adults, blood is taken from a vein in the place where the arm is bent. To do this, use a special needle. In children, blood fluid is taken with the help of a lancet.

It is also possible to take it from the heel, earlobe or thumb of the lower limb. After the procedure, a pressure bandage is applied to the site of the fence.

The resulting blood is placed on a special glass or in a test tube. Under laboratory conditions, the material is lowered into a special device - a centrifuge, where the serum is isolated. Thus, the concentration of LDH is determined.

Decryption

The interpretation of the results is carried out exclusively by a specialist. Doing it yourself is not recommended.

It is worth remembering: to confirm the presence of any pathological process, determining only LDH is not enough. To create a complete picture, all indicators of the blood fluid must be evaluated.

How to normalize values

If lactate dehydrogenase is elevated, first of all, it is necessary to establish the cause that could provoke such a condition. Only after the elimination of the underlying disease can the level of the enzyme be normalized.

Features of therapeutic measures:

1. With myocardial infarction, treatment begins immediately after the first signs of the disease appear or after a diagnostic examination. First of all, the patient needs to reduce the load on the heart muscle, ensure the supply of oxygen, and administer a medicine that normalizes blood circulation. During the entire period of therapy, the patient needs to constantly donate blood for analysis, which will allow monitoring the effectiveness of treatment. With correctly appointed measures, the value of LDH and other indicators will begin to decline.
2. If the increase in the concentration of the enzyme was provoked by iron deficiency anemia, then the doctor prescribes a special diet, which involves the use of foods that contain Fe and vitamin C, special medications that restore the norm of this element, and walks.
3. For oncological diseases, complex treatment is carried out, which includes the use of special drugs, chemotherapy and radiation therapy.
4. With an increase in LDH against the background of acute pancreatitis, painkillers, droppers with albumin or plasma, and digestive enzymes are prescribed. In the absence of a positive result, washing the abdominal cavity is done. In severe cases, surgery is performed, during which the pancreas is removed.

It is important to remember that only the attending physician can prescribe any drug.. Under no circumstances should you do this on your own.

Why is it important to keep the indicator normal

A significant increase in the level of the enzyme always indicates the development of a pathological process. In the absence of therapeutic measures or untimely diagnosis, any disease can provoke unpleasant consequences for the patient:

• transition to a chronic form;
• complication of the course of the disease;
• increases the likelihood of developing a heart attack or stroke;
• cancer processes;
• cirrhosis of the liver;
• fatal outcome.

Low LDH values ​​are most often not an indicator of the development of pathology.

The analysis, as a result of which the level of lactate dehydrogenase is determined, makes it possible to timely diagnose the presence of any serious disease even at the initial stage of its development. Therefore, even for preventive purposes, it is necessary to conduct a blood test regularly.

Increased activity of lactate dehydrogenase under physiological conditions is observed in pregnant women, newborns, and in persons after intense physical exertion.

An increase in the activity of lactate dehydrogenase in myocardial infarction is noted 8-10 hours after its onset. After 48-72 hours, the maximum activity is reached (an increase is usually 2-4 times), it remains increased for 10 days. These terms may vary depending on the size of the area of ​​the damaged heart muscle. An increase in the activity of total lactate dehydrogenase in patients with myocardial infarction occurs due to a sharp increase in lactate dehydrogenase 1 and partially lactate dehydrogenase 2. In patients with angina pectoris, an increase in lactate dehydrogenase activity is not observed, which makes it possible to use the determination of lactate dehydrogenase within 2–3 days after an angina attack as a highly reliable criterion for the absence of damage to the heart muscle.

A moderate increase in the activity of total lactate dehydrogenase is observed in most patients with acute coronary insufficiency (without myocardial infarction), myocarditis, with chronic heart failure, with congestion in the liver. In patients with cardiac arrhythmias, lactate dehydrogenase activity is usually normal, but with the use of electrical impulse therapy, it sometimes increases.

The source of increased activity of lactate dehydrogenase may be lung tissue in embolism and pulmonary infarction. The combination of normal AST activity, elevated lactate dehydrogenase activity, and increased bilirubin concentration can serve as a diagnostic triad of pulmonary embolism and to differentiate it from myocardial infarction. In pneumonia, enzyme activity may sometimes not increase.

With myopathies (muscular dystrophies, traumatic muscle injuries, inflammatory processes, disorders associated with endocrine and metabolic diseases), an increase in lactate dehydrogenase activity is observed; in neurogenic muscle diseases, the activity of lactate dehydrogenase does not increase.

In acute viral hepatitis, the activity of lactate dehydrogenase in the blood serum increases in the first days of the icteric period; in mild and moderate forms of the disease, it quickly returns to normal levels. Severe forms of viral hepatitis, and especially the development of liver failure, are accompanied by a pronounced and more prolonged increase in lactate dehydrogenase.

In obstructive jaundice in the first stages of blockage of the bile ducts, the activity of lactate dehydrogenase is normal, at later stages, an increase in lactate dehydrogenase activity is observed due to secondary liver damage.

With liver carcinomas or cancer metastases to the liver, an increase in lactate dehydrogenase activity may occur.

In the stage of remission in chronic hepatitis and cirrhosis of the liver, the activity of lactate dehydrogenase in the blood remains within the normal range or slightly increased. With an exacerbation of the process, an increase in enzyme activity is noted.

An increase in the activity of lactate dehydrogenase is characteristic of megaloblastic and hemolytic anemia, therefore its definition is used for the differential diagnosis of Gilbert's disease (normal LDH) and chronic hemolytic anemia (LDH elevated).

The activity of lactate dehydrogenase increases in acute and exacerbation of chronic kidney disease; in chronic kidney disease associated with uremia, it may be normal, but often increases after hemodialysis, due to the removal of enzyme inhibitors during this procedure.

Common lactate dehydrogenase (LDH) is an intracellular glycolytic enzyme that is involved in the reversible conversion of lactate to pyruvate and is found in most body tissues.

Russian synonyms

Lactic acid dehydrogenase.

SynonymsEnglish

Lactate dehydrogenase, Total, Lactic dehydrogenase, LDH, LD.

Research method

UV kinetic test.

Units

U / l (unit per liter).

What biomaterial can be used for research?

Venous blood.

How to properly prepare for research?

• Do not eat for 12 hours prior to the study.
• Eliminate physical and emotional overstrain 30 minutes before the study.
• Do not smoke for 30 minutes prior to the study.

General information about the study

Lactate dehydrogenase (LDH) is a zinc-containing intracellular enzyme that catalyzes the oxidation of lactic acid to pyruvate and is found in almost all cells of the body. LDH is most active in skeletal muscle, heart muscle, kidney, liver, and red blood cells.

There are five different forms (isoenzymes) of LDH, which differ in molecular structure and location in the body. Which of the five prevails depends on the main way of oxidizing glucose - aerobic (to CO 2 and H 2 O) or anaerobic (to lactic acid). This difference is due to the different degree of relationship of one or another isoenzyme and pyruvic acid. For the myocardium and brain tissue, LDH-1 is the main one, for erythrocytes, platelets, kidney tissue - LDH-1 and LDH-2. In the lungs, spleen, thyroid and pancreas, adrenal glands, lymphocytes, LDH-3 predominates. LDH-4 is found in all tissues with LDH-3, as well as in granulocytes, placenta and male germ cells, which also contain LDH-5. Isoenzyme activity in skeletal muscles (in descending order): LDH-5, LDH-4, LDH-3. For the liver, the LDH-5 isoenzyme is most characteristic, LDH-4 has less activity. Normally, in the blood serum, all fractions of the enzyme are determined with little activity as part of the total indicator - total LDH. Their activity in the blood is distributed as follows: LDH-2 > LDH-1 > LDH-3 > LDH-4 > LDH-5.

In diseases accompanied by tissue damage and cell destruction, LDH activity in the blood increases. In this regard, it is an important marker of tissue destruction. Although an increase in enzyme activity does not indicate a specific disease, its determination in combination with other laboratory tests helps in the diagnosis of pulmonary infarction, muscular dystrophy, and hemolytic anemia. Increased LDH activity can be detected in newborns, pregnant women and after intense physical exertion.

Previously, combined tests for LDH, aspartate aminotransferase and creatine kinase were widely used in the diagnosis of myocardial infarction. Now, for this purpose, the level of troponin is determined as a more specific marker of damage to the heart muscle. But the study of LDH activity remains an auxiliary analysis in the differential diagnosis of pain in the chest. In patients with angina, the activity of the enzyme does not change, but in myocardial infarction it begins to increase after 8-10 hours with a maximum in the first 24-48 hours after a heart attack and returns to normal after 10-12 days. An increase in LDH with normal AST activity 1-2 days after chest pain indicates a pulmonary infarction.

In the differential diagnosis of myopathies, this analysis helps to clarify the pathophysiological mechanisms of the disease. So, in violation of muscle function associated with neurogenic diseases, LDH does not increase, but when muscles are damaged due to endocrine and metabolic pathologies, LDH activity increases.

The activity of LDH in the blood can increase due to many malignant neoplasms, with effective treatment it decreases, which is sometimes used for dynamic monitoring of cancer patients.

What is research used for?

• For the diagnosis of acute or chronic tissue damage during a comprehensive examination of the patient.
• For the differential diagnosis of diseases with severe chest pain (myocardial infarction, angina pectoris, pulmonary infarction).
• To detect diseases accompanied by hemolysis of erythrocytes.
• In order to monitor the course of oncological diseases during therapy.
• For the study of pathologies of the liver and kidneys.
• For the diagnosis of lesions of muscle tissue.

When is the study scheduled?

• When acute or chronic damage to tissue and cells in the body is suspected.
• With a comprehensive preventive examination of the patient.
• When monitoring the course of certain chronic diseases (muscular dystrophy, hemolytic anemia, diseases of the liver, kidneys), oncological pathology.

What do the results mean?

Reference values

Reasons for increased activity of lactate dehydrogenase total:

• myocardial infarction,
• pulmonary embolism and pulmonary infarction,
• blood diseases accompanied by hemolysis (hemolytic, pernicious, megaloblastic, sickle cell anemia, erythremia),
• malignant neoplasms of various localizations (testicular cancer, liver cancer, lymphoma, metastases to bone tissue and liver, etc.),
• leukemia,
• liver pathology (viral and toxic hepatitis, liver cirrhosis, obstructive jaundice, alcoholic liver disease),
• kidney disease (kidney infarction, glomerulonephritis, pyelonephritis),
• muscle pathology (muscular dystrophy, trauma, atrophy),
• bone fractures,
• congestive heart failure, acute coronary insufficiency (without a heart attack), myocarditis (moderate increase in the enzyme),
• Infectious mononucleosis,
• intestinal infarction,
• acute pancreatitis,
• stroke,
• convulsive seizure,
• delirium tremens,
• eclampsia,
• traumatic shock,
• severe conditions accompanied by hypoxia, hyper- and hypothermia,
• burn disease,
• pneumocystis pneumonia,
• premature detachment of the placenta,
• hypothyroidism.

What can influence the result?

The result can be improved by:

• intense physical activity shortly before the study,
• the patient has a prosthetic heart valve (erythrocyte hemolysis due to cell damage by the valve leaflets),
• the use of electropulse therapy shortly before the study,
• hemodialysis (due to the removal of enzyme inhibitors - urea during the procedure),
• a large number of platelets (thrombocytosis),
• some skin diseases
• drugs that increase LDH activity (anesthetics, aspirin, vasopressin, valproic acid, narcotics, procainamide, ethanol, amiodarone, anabolic steroids, verapamil, isotretinoin, captopril, chloramphenicol, codeine, dapsone, diltiazem, interferon-alpha, interleukin-2, some antibacterial and antifungal drugs, non-specific anti-inflammatory drugs, penicillamine, streptokinase, thiopental, furosemide, methotrexate, sulfasalazine, simvastatin, tacrolimus).

Possible reasons for the decrease in the result:

• the presence of oxalates and urea, which inhibit the enzyme,
• drugs that reduce LDH activity (amikacin, ascorbic acid, hydroxyurea, dofibrate, enalapril, metronidazole, naltrexone, anticonvulsants, cefotaxime).

Important Notes

• Due to the non-specificity of this analysis, its result should be interpreted taking into account the indicators of other laboratory tests and the clinical picture of the disease.
• In the diagnosis of acute processes accompanied by tissue destruction (infarction, necrosis), it is necessary to take into account changes in plasma LDH activity for some time after an acute episode of the disease.
• Determination of LDH isoenzymes helps to clarify the localization of the pathological process.
• The main laboratory marker of myocardial infarction is troponin I, not LDH.

• Lactate dehydrogenase 1, 2 (LDH 1, 2 fractions)

Who orders the study?

Therapist, cardiologist, oncologist, general practitioner.

Literature

• Nazarenko G.I., Kishkun A. Clinical evaluation of laboratory results. - M .: Medicine, 2000. - 165-166.
• Fischbach F.T., Dunning M.B. A Manual of Laboratory and Diagnostic Tests, 8th Ed. Lippincott Williams & Wilkins, 2008: 1344 p.
• Wilson D. McGraw-Hill Manual of Laboratory and Diagnostic Tests 1st Ed Normal, Illinois, 2007: 347-348 pp.

The LDH norm is an important blood indicator that can warn about the presence of pathologies in the body of a child or adult. LDH refers to lactate dehydrogenase. This is an enzyme located inside the cells with a zinc content. With its help, the process of oxidation of lactic acid proceeds. LDH is present in almost all systems, however, it is most often seen in the musculature of the skeleton, the muscles of the heart, the kidneys, etc.

LDH in the blood can be divided into five subspecies, the differences of which are associated with the structure at the molecular level and location. From which LDH is greater, the method of glucose oxidation will be selected. There are two options - aerobic or anaerobic. In the first case, the result will be carbon dioxide with water, in the second lactic acid.

LDH 1 and 2 are present mainly in the heart muscle. The third number refers to the lungs, and the fourth and fifth are observed in the muscles of the skeleton.

In diseases that damage tissues or destroy cells in the body of women and men, LDH becomes elevated. That is why LDH in the blood acts as an important indicator, changes in which are associated with tissue damage.

It should be noted that an increase in LDH in the analysis is not a sign of a specific disease, its biochemistry helps when working with lung infarctions, muscular dystrophy and anemia of a hemolytic nature. At the same time, lactate dehydrogenase is increased in pregnant women, children and adults after intensive sports for physiological reasons.

Deciphering when the biochemical analysis was obtained is not difficult. The normal values ​​depend on the age of the patient. So in the analysis of newborns in the first four days of life, the LDH indicator should be at least 750 U / l. For the period from the fourth to the tenth day of life, at least 2000 U / l.

Starting from the tenth day, the decrease in the indicator starts. In particular, in the analysis of a baby up to two years old, LDH should be at a level of at least 420 U / l. The next age category is children from two to 12 years old. Their biochemistry should show at least 295 U/L. For children over 12 years old, the norm is at the level of 250 U / l. The same results will be found in the analysis in adults. Starting from the age of 12, the norm indicators remain unchanged.

When is such detailed biochemistry necessary? Most often, the analysis is prescribed when a violation of the integrity of tissues is suspected, no matter the chronic or acute nature. This is a component of the examination of the patient in the complex. Sharp chest pain also requires such an examination. Often the causes of acute pain lie in:

• myocardial infarction;
• angina;
• lung infarction.

Diseases associated with erythrocyte hemolysis may also be the reason for the appointment for analysis. In therapy aimed at combating oncology, this analysis is also included in the list of mandatory. Studies of hepatic, renal pathologies, as well as muscle lesions are all reasons to go for analysis.

Deviations from the norm

Sometimes the decoding of the analysis shows that the level of LDH is lowered. By the way, this is much less common than an increase. If LDH is low, the reasons may lie in the active breakdown of glucose by the body. For example, this indicator may be lowered due to serious physical exercises. The body is desperate for energy, which is why glucose is broken down too quickly.

However, there are also less harmless reasons. In particular, we are talking about two types of genetic level mutations, due to which the decoding of the analysis will always show a decrease.

In particular, with the first type of mutation, people are very often prone to fatigue and muscle weakness. In the second type, there are usually no pronounced symptoms. The level of LDH in the analysis can be affected by excessive use of ascorbic acid.

Most often in the analysis you can see an increase in this indicator. Deciphering this phenomenon is a little more complicated, since there are more reasons for the increase. Most often this is due to the defeat of the body by diseases that lead to the destruction of tissues and cells.

This increase occurs when:

• myocardial infarction;
• various hepatitis;
• jaundice;
• cirrhosis of the liver;

• acute leukemia;
• pancreatitis in its acute form;
• kidney pathologies;
• skeletal muscle damage;
• the use of various drugs and caffeine.

A slight increase in LDH may indicate the presence in the patient's body of acute coronary insufficiency, myocarditis, chronic cardiac pathologies, or hepatic congestion.

Often, in people who have cardiac arrhythmia, the enzyme does not lose its activity and demonstrates the norm. However, if you use the therapy of electrical type impulses, you will notice that the indicators are slightly higher than necessary. It happens that an increase in LDH occurs in infants due to physiological characteristics that cannot be considered a deviation from the norm.

You can notice an increase in enzyme activity during exacerbation of various chronic pathologies in the kidneys. At times, the concentration of this enzyme shows a normal indicator, and at times, after the organization of hemodialysis, the enzyme rises.

By determining the LDH subtype, pathology can be localized. That is, immediately determine in which system there are violations in a person.

Important information about the analysis

It is worth noting that any laboratory study can demonstrate false indicators. Most often this is due to the lack of knowledge of the examiners about how to properly prepare for such tests.

In particular, hemolysis of erythrocytes in a blood sample can increase the result in the analysis. This is due to the high activity of LDH in blood cells. If the patient performed intense physical exercises shortly before the study, then the risk of obtaining an incorrect result is also high.

Patients using a prosthetic heart valve should notify their physician as this may improve outcome because the valve leaflets damage blood cells. Shortly before the study, it is necessary to exclude electropulse therapy, as well as hemodialysis.

A large number of platelets in human blood also does not help in the correct determination of LDH, as well as a number of drugs, as well as skin diseases. It is necessary to exclude any anesthetics, aspirin-containing drugs, a number of antibacterial and anti-inflammatory drugs.

It should also be understood that this analysis is non-specific. In accordance with this, the interpretation of the result is carried out taking into account a number of indicators that are provided by other studies in the laboratory.

When it comes to determining processes in an acute form that are associated with tissue damage, it is necessary to calculate the change in plasma LDH activity within a short time period after an exacerbation. When determining myocardial infarction, it is worth highlighting troponin I, and not LDH, as the main indicator.

The criterion under consideration may deviate from normal values ​​in a number of different diseases. The reasons for the increase in the concentration of lactate dehydrogenesis may be:

• myocardial infarction, accompanied by ischemic necrosis of the middle layer of the muscular tissue of the heart;
• blockage of a lung artery by a thrombus or pulmonary infarction;
• blood pathologies, which are characterized by the destruction of red blood cells (various types of anemia, hemolysis, severe intoxication);
• malignant tumors affecting various organs and tissues, often accompanied by metastasis;
• violations in the liver against the background of chronic and acute hepatitis, Gospel disease or alcohol intoxication;
• kidney pathology (glomerular nephritis, pyelonephritis);
• atrophy or injury of muscle tissue;
• open and closed fractures;
• congestive heart or coronary insufficiency;
• inflammation of the heart muscle tissue;
• mononucleosis, viral etiology;
• acute attack of pancreatitis;
• seizures;
• alcoholic delirium (mental abnormalities against the background of a sharp withdrawal of alcohol);
• burn disease;
• abruption of the placenta ahead of time;
• hyperthyroidism.

When identifying the causes of an increase in LDH in women and men, it is necessary to exclude the influence of factors that can lead to unreliable results:

• incorrect blood sampling, as a result of which erythrocytes are destroyed in the test tube (hemolysis);
• neglect of the rules for preparing for the delivery of biomaterial: physical and emotional stress, smoking, alcohol, improper diet;
• the use of treatment methods, accompanied by electrical stimulation of the patient a week before the analysis;
• an excess of platelets in the blood;
• taking medications that activate the enzyme system.

Ldg and creatinine are elevated

Creatinine is a metabolite, a by-product of amino acid-protein metabolism in the human body. It is produced by creatine molecules, which play an important role in the functioning of the muscular system. It helps to carry out energy metabolism in all tissues - especially muscle tissue.

Creatinine is “born into the world” when protein compounds are broken down and energy is released. This most often occurs during the digestion of food, during physical work, in which the muscles are always involved.

After its “birth”, creatinine enters the blood, and it delivers it to the kidneys. There it is filtered and then leaves the body with urine.

Doctors, based on data on the level of creatinine in the blood, learn about the protein metabolism and kidney status of the patient. With it, you can detect many diseases in the early stages.

Permissible norm of creatinine

The permissible norm of creatinine depends on gender, age, lifestyle, level of physical activity and hormonal processes, the constitution of the human body. In a healthy body, the concentration of the metabolite in the blood remains stable around the clock, rising only slightly when the muscles contract. Sharp jumps in creatinine are a sign of severe renal ailments.

Low creatinine - causes

Low levels of creatinine in the blood (hypocreatinemia) are rare. This is a sign of problems with protein metabolism throughout the body or in only one muscle tissue.

Renal dysfunctions do not have a special effect on the concentration of this metabolite in the blood. Here the problem is different: the body's protein resources accumulated in the muscles are depleted.

By itself, low creatinine is not a disease, it does not need to be treated. There are many factors that reduce its concentration, and in men and women they can be different. Here are the common reasons for its decline for both sexes:

What is LDH

Lactate dehydrogenase is one of the enzymes that shows the presence of damaged cells. It is found both in the blood and in tissues in varying amounts. In the process of respiration, lactic acid salt is formed in the cells. Lactate dehydrogenase promotes its transition to pyruvic, which is involved in the high-energy oxidation process. It contributes to the rapid release of energy from glucose, which is necessary for muscle contraction, the flow of biochemical processes. The result is products that are easily removed from the body - carbon dioxide and water. If insufficient oxygen is supplied, the enzyme accumulates, pathologies arise that accelerate cell decay. They will lead to the fact that lactate dehydrogenase is increased. This indicator is very sensitive to the destruction of cellular structures.

Lactate dehydrogenase, if arranged in decreasing order of quantity, is found in the following organs and tissues:

• In the kidneys.
• Heart muscle.
• Skeletal muscles.
• pancreas.
• Spleen.
• The chemical laboratory of our body is the liver.
• Lungs.
• in blood serum.

The reasons

As a result of the study, it can be determined that LDH is elevated. Such a condition indicates deviations in the work of the body. According to the results of one analysis, it is impossible to accurately diagnose, it is only possible to confirm the development of the pathology. To identify the true reasons for which LDH is elevated, it is necessary to conduct additional instrumental studies.

Possible reasons:

• liver pathology - most often there is an increase in indicators with cirrhosis of the liver, as well as with various changes in the structure of tissues due to alcoholism or viral hepatitis;
• infarction of the heart, kidney, lungs, intestines - with myocardial infarction, the level of the enzyme rises in the first two days after the attack and remains elevated for about 11-12 days. A pulmonary infarction is accompanied by chest pain and can increase LDH levels;
• oncology;
• pyelonephritis;
• blood ailments that provoke hemolysis;
• acute pancreatitis;
• lack of oxygen in the body;
• meningitis. A similar phenomenon can cause the development of encephalitis;
• injuries and atrophy of muscle fibers;
• lymphoma;
• broken or cracked bones;
• extensive burns;
• detachment of the placenta during pregnancy;
• hyperthermia.

The value of indicators of LDH isoenzymes

If we consider in more detail the increase in lactate dehydrogenase of a certain type, then we can determine the foci of a possibly developing pathology.

An increase in LDH-1 or the ratio of LDH-1 / LDH-2 is possible under the following conditions:

• Acute heart attack.
• Hemolytic megaloblastic anemia.
• Acute kidney necrosis.
• In the presence of tumors of the male and female reproductive organs.

An increase in LDH-5 is typical for:

• Liver diseases.
• Cancer.
• Injury to skeletal muscles.

An increase in LDH-2 and LDH-3 is usually observed with:

• Acute leukemia.
• Chronic granulocytosis.

An increase in LDH-3, possibly partially LDH-4 and LDH-5 most often occurs if there are:

• Kidney diseases.
• Pulmonary embolism.
• Heart failure that develops with the involvement of lung tissue.

An increase in LDH-4 LDH-5 is detected if diagnosed:

• Circulatory failure due to weak heart function.
• Liver damage.
• Muscle injury.

The norm of LDH in the blood

In a healthy person, the enzyme lactate dehydrogenase does not accumulate in the body, but is neutralized or excreted naturally. But, some pathologies that lead to cell breakdown will certainly lead to an increase in LDH.

There are set limits when it is said that LDH is normal. The rate of the indicator, to a greater extent, depends on the age of the patient, since at the beginning of life the level of the enzyme reaches the highest values, and over the years, the blood lactate rate decreases markedly.

So, for newborns, an LDH analysis is considered normal if it is less than 2000 U / liter of blood, or 2.0 μmol / h * l. In children under 2 years old, the level of the enzyme is still quite high, and no more than 430 U / l is considered the norm. In children under 12 years of age, an indicator of no more than 295 U / l is taken as the norm. As for adults, the norm of LDH in the blood in women is approximately from 135 to 214 U / l, and in men - 135-225 U / l.

Treatment

Further treatment of patients with elevated LDH levels depends on the underlying cause of such a change. To begin with, the attending physician prescribes an extended blood test, ultrasound diagnostics, MRI, CT. If liver disease is suspected, in addition, liver tests, an analysis for hepatitis, are prescribed.

Based on the data obtained, antiviral, hepatoprotective, immunomodulatory drugs can be prescribed.

If anemia has become the cause of the deviations, then Maltofer, Sorbifer, Ferrum-Lek, Fenyuls and other iron-containing drugs are prescribed. In oncological diseases, an integrated approach is used, which includes the use of specialized medications and chemotherapy. In myocardial infarction, cardioprotectors and drugs that support heart function are prescribed.

It is important to know that only the attending physician can prescribe any medications and procedures, based on the results of the tests and the individual characteristics of the body. The use of traditional medicine should also be agreed with the doctor.

In combination with drug treatment, a certain diet is prescribed.

It eliminates bad habits, fatty, spicy, smoked and canned food.

Lactate dehydrogenase is elevated

As already noted, the main reason for the increase in lactate levels is the destruction of cellular structures in some pathological conditions. Ldg increased causes:

• myocardial infarction or heart failure;
• stroke;
• lung infarction or pulmonary insufficiency;
• kidney disease;
• cirrhosis of the liver;
• hepatitis, jaundice;
• acute pancreatitis;
• blood diseases (leukemia, anemia, etc.);
• cancerous tumors in organs;
• acute skeletal and muscular injuries (atrophy, dystrophy, etc.);
• hypoxia, oxygen deficiency in organs and tissues, respiratory failure;
• if LDH is elevated during pregnancy, in most cases this is considered normal, or it becomes a signal of placental abruption.

These are the most common cases in which an elevated LDH enzyme is detected in a biochemical blood test. However, it happens that lactate dehydrogenase is increased and the reasons for this are physiological, that is, the indicator is false and does not indicate the development of pathology in a person. Provoking factors may be:

• some skin diseases;
• severe physical and psychological stress on the eve of the test;
• alcohol consumption;
• the use of certain drugs (especially insulin, aspirin, anesthetics);
• thrombocytosis.

Since each organ has the so-called LDH isoenzymes (LDG1,2,3,4,5). With an increase in LDH 1 and 2, we are most likely talking about myocardial infarction, and a high concentration of the enzyme in the blood lasts for 10 days after a heart attack. With the growth of LGD 1 and 3, one can suspect the development of myopathy in a person. If LDH 4 and 5 enzymes are especially active, then liver disorders can be judged, for example, in acute hepatitis

Also, these isoenzymes can be increased in case of damage to muscles and bones, with possible damage to internal organs. If you suspect the development of cancer, especially pay attention to the concentration of LDH 3, 4 and 5

With an increase in LDH, the doctor may prescribe an additional blood test for SDH, this analysis gives more accurate results.

Situations when LDH is lowered in the blood are extremely rare. And as a rule, an analysis with such a result has no diagnostic value. This situation is usually attributed to errors during laboratory testing. Sometimes, a decrease in the level of the enzyme is associated with the use of ascorbic acid or vitamin C in large quantities.

What is the definition of LGD used for?

Blood lactate testing is often ordered to confirm the diagnosis. However, if earlier this diagnostic method was popular and widely used, today its role is gradually losing its significance, since it has been replaced by more accurate and reliable methods of analysis. However, such studies can be quite costly and technically complex.

For research, blood is taken from a vein, it is considered the most concentrated and easier to process. After sampling, the necessary serum is extracted from the blood, which determines at what level the patient has lactate. The results of the analyzes are usually ready on the 2nd day after the study.

Thus, with the help of LDH analysis, it is possible to timely detect the presence of diseases, disorders, and pathological processes in a person at a very early stage, before the appearance of characteristic symptoms.

Clinical significance of determining the activity of lactate dehydrogenase

Already a few hours after the onset of acute myocardial infarction in the blood serum, a significant increase in L activity is noted. After 36-48 hours. this activity reaches its maximum (often it is 10-15 times higher than normal). The optimal period for determining the activity of L. in the blood serum is 2-4 days after the onset of a heart attack, since during this time period the value of this biochemical test is greatest. So, for example, its diagnostic accuracy, according to IV Martynov, in transmural myocardial infarction in this period of time is 97 ± 1.7%.

Usually, the activity of L. in the blood serum during a heart attack returns to normal on the 10-12th day after the onset of the disease. Activity L. in blood serum at a myocardial infarction remains raised longer than other enzymes (eg, aminotransferases).

The value of determining the activity of L. in the blood serum is especially high in unclear cases of myocardial infarction (with an atypical wedge, and electrocardiographic patterns, in particular with prolonged anginal attacks, accompanied by transient deformation of the S T segment or T wave without the appearance of patol, Q wave), as well as for differential diagnosis between myocardial infarction and dissecting aortic aneurysm, acute pericarditis and pulmonary thrombosis. With all these diseases, the increase in L.'s activity in the blood serum is not as sharp as in myocardial infarction.

However, the magnitude of L.'s activity does not allow us to judge with certainty the size of the damage to the heart muscle, and even more so to predict the outcome of the disease.

In patients with angina pectoris, there is no increase in L.'s activity in the blood serum. This allows the LDH test to be used as a reliable criterion for the absence of damage to the heart muscle within 2-3 days after a heart attack.

L.'s activity in the blood serum increases with parenchymal hepatitis in the first days of the icteric period. With a mild and moderate form of the disease, the activity of the enzyme quickly returns to normal. With obstructive jaundice, L.'s activity in the blood serum remains normal, only in the later stages of the disease does it increase due to secondary damage to the liver parenchyma. With liver carcinomas and cancer metastases to the liver, L.'s activity in the blood serum may also increase; while the concentration of pyruvate in the blood serum increases by 2-3 times (the norm is 0.5-1.0 mg%). However, a negative LDH test result in this case does not at all indicate the absence of a malignant liver lesion.

In a stage of remission hron, hepatitis L.'s activity in blood serum remains within norm or slightly raises, at an aggravation of process increases. In this case, the LDH test can be used as an auxiliary test along with other enzyme tests.

L.'s activity in blood serum also increases with progressive muscular dystrophy, hron, lymphogranulomatosis, leukemia, pernicious anemia, acute and hron, nephritis, with tumors in the urinary tract and other diseases.

More important in diagnosis than the determination of the total activity of serum L. is the determination of the isoenzyme composition of L.

Usually, in the blood serum of healthy people, all 5 fractions of L. are found, the activity of which is distributed as follows: LDH2> LDH1> LDH3> LDH4> LDH5. In acute myocardial infarction, the ratio between the activities of LDH1 and LDH2 changes so that the activity of LDH1 becomes equal to or higher than the activity of LDH2. This indicator is of great importance in the late diagnosis of myocardial infarction. In addition, due to the specificity of this test, it can be used for differential diagnosis.

With parenchymal damage to the liver tissue (infectious hepatitis), as well as with some muscle diseases (progressive muscular dystrophy), a significant increase in the relative content of LDH5 is found, which is also used in enzymatic diagnosis of these diseases.

See also Dehydrogenases.

Bibliography: Nyosholm E. and Start K. Regulation of metabolism, trans. from English, p. 111, 291, Moscow, 1977; With e in e r and N S. E. Glycolysis, in the book: Khim. Osnovy protsessov shiznedeyat., ed. V. N. Orekhovich, p. 156, M., 1962; Harris G. Fundamentals of human biochemical genetics, trans. from English, p. 53, M., 1973; Holbro ok J. J. a. about. Lactate dehydrogenase, in: Enzymes, ed. by P. D. Boyer, v. And, p. 191, N. Y.-L., 1975, bibliogr.

Conducting research

When the indicator of lactate dehydrogenase is elevated, you need to focus on the reasons that caused such a condition. This analysis is carried out in exactly the same way for both adults and children.

The process of blood sampling does not cause pain, so parents should not worry. Blood is taken only from a vein, because it is the most concentrated, and for laboratory processing this is a very important indicator.

As soon as the blood is received, the laboratory assistant extracts serum from it, the remaining components for biochemical analysis are not needed. Further, after carrying out certain manipulations, you can find out whether the lactate in the blood of the baby is increased or decreased. Sometimes the test results are not issued immediately on the second day. The fact is that the material can be stored a little longer, the main thing is that certain conditions are met. For example, if the storage temperature is 20 degrees, then the serum can be stored for another month and a half.

Only blood must be brought to the laboratory within the same two days in order to get serum from it in time. If all parameters are met, then the results obtained can be considered one hundred percent accurate.

To pass an analysis for the determination of lactate dehydrogenase, the patient does not need any special preparation.

But important rules should not be missed:

1. Blood is taken early in the morning, on an empty stomach.
2. In terms of nutrition, you can leave everything as it is.
3. You can do sports exercises in the same rhythm, but do not overwork much.

Otherwise, there are no special instructions. Despite the fact that the procedure is painless, it is still something unknown and unusual for children. So before the upcoming procedure, it is worth preparing him: talk to him calmly, tell everything the way it will happen. When the child is ready, then the procedure will seem normal.

The analysis for lactate dehydrogenase may exceed normal standards, be reduced, or equal to the norm. With an increase in LDH, we can talk about the presence of certain types of anemia, hepatitis, hypoxia, or carcinomatosis.

Whatever the conclusion of the doctors, each parent must respond to the condition of his child, because each disease has its own symptoms. The body always signals about all deviations, especially in childhood.

Also, the child has not yet had time to get used to all manifestations of the external environment. The body only adapts to all sorts of changes. This is how many doctors explain the frequent diseases of the younger generation. Over time, the immune system, knowing this or that irritant, is able to give its answer, then infection will not occur. But preventive measures should not be forgotten, they will help increase immune protection.

How the analysis is done

To assess the level of LDH and its enzymatic activity, 2 groups of methods are used:

• spectrophotometric, the essence of which is to determine the difference in the absorption spectra of the oxidized form of NAD (a coenzyme of all living cells) from the reduced one;
• colorimetric, subdivided into dinitrophenylhydrazine - determining the concentration of pyruvate, and redox indicator - identifying certain molecules using indicators that change color.

An optical test is used as standards for determining the enzymatic activity of LDH, and electrophoresis is used for isoenzymes. When issuing the results of the analysis, the laboratory must indicate the chosen method.

Normalization of LDH levels in the blood

Patients often ask the question - how to reduce the level of the enzyme? To do this, it is necessary to initially establish the exact cause of the increase in LDH. Only when the disease that was the cause is eliminated, it is possible to return the indicator to normal values. Therapy for each of the pathologies has its own characteristics:

• after the first signs of myocardial infarction, a person needs first aid. Any delay in treatment can lead to death and serious complications. In order to assess the risk of relapse, a control measurement of the level of LDH is carried out, which, with adequate therapy, should return to normal;
• in case of anemia provoked by iron deficiency, the patient's nutrition is corrected, and iron-containing preparations are prescribed. A favorable outcome is considered to be an increase in hemoglobin levels and a decrease in LDH;
• in oncopathology, a large-scale patient screening is necessary to assess the size of the tumor, the presence of metastases, and the degree of organ damage. At the same time, the evaluation of the effectiveness of treatment includes an analysis for LDH and the main tumor markers. The lack of positive dynamics, expressed in a decrease in the considered criteria, is the reason for transferring the patient to more aggressive methods of treatment;
• in the case of acute pancreatitis, it is necessary to place the patient in a round-the-clock hospital. Treatment includes droppers with painkillers, antibacterial and anti-inflammatory drugs. As the patient's condition improves, all biochemical parameters return to normal.

Determination of LDH level

The blood is examined for the content of LDH using a special technique called the "UV test". Blood is taken from a vein, in the morning (up to 10) and on an empty stomach. The resulting substance is then subjected to centrifugation to isolate serum from plasma.

At the same time, it is very important that the serum is clear, without traces of erythrocyte decay, otherwise the result may be incorrect.

Attention! It is undesirable to smoke and drink alcohol on the eve of the analysis. In addition, you should not eat 6-8 hours before the study, while it is necessary to limit the intake of protein and fatty foods.

Intensive sports can also distort the result. The final indicator is also affected by the medications taken, so it is worth postponing the medication on the day of the study. Usually, the result of the analysis can be found already on the 2nd day of the examination.

When LDH is high

An increase in the concentration of LDH occurs with the following pathologies:

• stroke
• myocardial, intestinal or lung infarction
• pulmonary insufficiency
• hypoxia
• acute pancreatitis
• diseases of the pancreas
• reduced blood pressure
• diseases that affect the hepatobiliary complex
• cancer of the blood, kidneys, testicles, etc.
• cirrhosis of the liver
• jaundice (in the early stages of the disease)
• iron deficiency or pernicious anemia
• eclampsia
• placental abruption
• some fungal diseases
• lymphoma
• hepatitis
• Infectious mononucleosis
• skeletal muscle injury, traumatic shock
• dystrophic condition
• glomerulonephritis
• leukemia
• oxygen deficiency

In order to accurately determine where the pathological process takes place, it is necessary to analyze which particular LDH isoenzyme is elevated.

An increase in LDH-1 or LDH-2 levels most often indicates a heart muscle infarction. If the concentration of LDH-1 and LDH-3 is increased, then it can be assumed that the patient develops muscle tissue atrophy. Excessive activity of LDH-4 and 5 isoenzymes often indicates abnormal liver function, as well as muscle and bone damage.

If an oncological disease is suspected, then the greatest attention is paid to the amount of LDH-3, 4 and 5

Important! Elevated LDH can be detected in conditions such as:

• alcohol consumption
• psychological stress or increased physical activity
• certain skin diseases
• certain medications (most commonly aspirin, anesthetics, fluoride, oral contraceptives, and insulin)
• thrombocytosis

When LDH is low

A decrease in the concentration of lactate dehydrogenase in the blood is characteristic in the following situations:

• the use of a large amount of ascorbic acid;
• high levels of oxalic acid salts (oxalates) in the urine
• a peculiar reaction to cystotic chemotherapy.

A decrease in LDH is very rare and is not always interpreted as evidence of disorders in the body.

Norm of LDH in the body and decoding of the analysis

When analyzing blood, the norm is usually indicated in units / l, which means one per liter. The decoding of the analysis takes into account the age and gender of the patient. In the blood of a healthy adult, a relatively small amount of the enzyme is found. In a child under two years old, an indicator within 430 units / l is considered the norm.

An increase in lactate dehydrogenase occurs during pregnancy, in newborns, and in professional athletes.

Based on the identified marker, it is impossible to determine which cells were damaged. Therefore, it is necessary to know when deciphering LDH, what are its isoenzymes. Some laboratories conduct additional tests that determine several forms of a substance, starting with the most mobile:

the first indicates a problem with the heart, kidneys, and red blood cells;

the second is found mainly in cardiomyocytes and erythrocytes;

the third is found in the tissues of the lungs, endocrine glands and adrenal glands;

the fourth is an enzyme in white blood cells, liver, placenta and male testicles and muscle tissue;

the fifth is found in all organs containing LDH-4, as well as skeletal muscles.

Deciphering biochemistry for an increase in LDH in the blood is now considered less informative.

High values ​​of all isoenzymes determine the pathology of several organs. Myocardial infarction with congestive heart failure causes lung damage and liver congestion. In cancers and autoimmune diseases such as lupus, lactate dehydrogenase is generally elevated. Hypoxia, shock, and burns are accompanied by cell death, which indicates an increase in LDH. Caffeine also affects the amount of the enzyme in the blood.

The dynamics of the first isoenzyme is more sensitive and specific than the increase in LDH in general. Usually the level of the second isoenzyme is higher than the first. If the concentration of LDH-1 rises relative to LDH-2, a heart attack is diagnosed. Usually, the norm of LDH in the blood is exceeded 12-24 hours after damage to the heart tissue and for two days in 80% of cases. A normal LDH-1/LDH-2 ratio is reliable evidence that there was no attack. The ratio of total LDH and LDH-1 is called hydroxybutyrate dehydrogenase. Therefore, with a heart attack:

the LDH/HBDG figure is lowered (less than 1.30);

the LDH-1/LDG-2 ratio approaches 1 and sometimes exceeds this value.

On the first day, myocardial infarction is diagnosed in terms of creatine kinase, and a day later, according to the enzymatic study of LDH. The activity of the substance is directly related to the area of ​​damage to the heart muscle.

Other severe diseases reflect on the ratio of isoenzymes and coefficients:

hemolytic anemia is characterized by low LDH / HBDG - up to 1.3 and below;

with megaloblastic anemia, LDH-1 significantly exceeds LDH-2;

the overall level increases with acute necrotic processes and cell death, such as damage to the kidney parenchyma;

tumors in the sex glands (ovaries and testicles) are accompanied by an isolated increase in LDH-1.

Most often, LDH is elevated due to the destruction of the tissues of the hepatic and renal parenchyma, and the death of platelets and erythrocytes.

LDH in a blood test is considered in relation to other indicators:

In anemia, red blood cells are destroyed, which releases large amounts of LDH into the blood. The disease is diagnosed against the background of low hemoglobin. Weakness, pallor, shortness of breath may be indications for examination.

Blood cancer is associated with the production of abnormal blood cells, which is reflected in the levels of many indicators: LDH, aspartate aminotransferase, bilirubin, urea. At the same time, there is a decrease in the level of glucose and the blood coagulation factor fibrinogen. A biochemical blood test allows you to suspect a pathology and refer the patient to identify tumor markers.

Along with the LDH indicator in the blood, which indicates the death of pancreatic cells, bilirubin and glucose will increase. The primary indicator is the level of the pancreatic enzyme amylase.

Causes of increased lactate dehydrogenase

The level of LDH can rise for various reasons, with the occurrence of certain pathologies and diseases.

Among the reasons for the increase in lactate dehydrogenase values ​​are noted:

• congestive heart failure.
• Myocardial infarction. When such a condition appears, the concentration of LDH in the blood increases sharply in the first two days (up to 55 hours), and then remains for about 10 days, but this interval is different for each patient. In one person, an increased LDH value after a heart attack persists for 3-4 days, in another - for 7-10 days.
• Lung infarction. In this case, an increase in LDH is noted almost immediately with the appearance of a sharp pain in the chest.
• Various pathological conditions of the kidneys.
• Stroke.
• Lymphoma.
• Leukemia.
• Bowel infarction.
• Various diseases of oncology.

• Anemia of various etiologies and other blood diseases accompanied by hemolysis.
• Pancreatitis in acute form.
• Infectious mononucleosis.
• Bone damage, such as broken bones.
• Pathological conditions of the muscles, in particular, atrophy, dystrophy or injury.
• Hypothermia, hyperthermia, as well as various conditions that are accompanied by hypoxia.
• Shock in case of injury.
• Burns of large areas of the skin.
• Seizures of a convulsive nature.
• White fever.
• Eclampsia.

The reason for the increase in LDH can be the period of pregnancy. Since an increase in the indicator during this period may be a variant of the normal value, but at the same time, such a condition may also indicate the occurrence of placental abruption.

Other reasons can also cause an increase in the result (false or physiological), in particular:

• Exercising during the day before blood sampling or any strenuous exercise.
• The use of hemodialysis.
• The use of alcoholic beverages in the days before the analysis.
• Carrying out procedures of electropulse therapy within 1-3 days before blood sampling.
• The presence in a person of a special valve prosthesis in the heart, leading to hemolysis of red blood cells.
• Some types of skin diseases.
• The presence of thrombocytosis.
• Taking certain drugs that can affect the concentration in the body of LDH, in particular, non-specific anti-inflammatory drugs, anesthetics, anabolic steroids, sulfonamides, codeine, caffeine, penicillin, insulin, as well as valproic and acetylsalicylic acid.

Indications for analysis

A person can be prescribed a study for LDH in the blood if:

• Carrying out the diagnosis of diseases of the heart or lungs, when the patient has complaints of frequent and severe pain in the chest area, as well as when a myocardial infarction is detected.
• Diagnosis of muscle pathologies and malignant neoplasms.
• Conducting comprehensive examinations to determine the general condition.
• Monitoring the treatment of various oncologies, evaluating the effectiveness of therapy, as well as monitoring the development of certain ailments.
• The appearance of suspicions that the patient has damage to cells and tissues in a chronic or acute form.

The study is of particular diagnostic value for:

• General diagnostics during complex examinations.
• Diagnosis of heart attacks, primarily of the heart muscle, as well as the lungs and other organs.
• Diagnosis of angina pectoris.
• Identification of ailments that are accompanied by the process of hemolysis of red blood cells.
• Diagnostics of pathologies of some organs, for example, kidneys or liver, as well as muscle tissue.

Also, the study is often carried out by cancer patients in order to monitor the development of tumor processes and determine the degree of effectiveness of the therapy.

The LDH (lactate dehydrogenase) test is a non-specific test that is used when a number of diseases and conditions are suspected. The enzyme enters the blood plasma during the destruction of almost any cell in the body, including bacterial cells. Therefore, the level of LDH in the blood is a general indicator of tissue and cellular damage. Sometimes an assessment of the concentration of a substance is carried out on the cerebrospinal or pulmonary fluid in the presence of certain diseases.

The importance of the enzyme in the body

Interest in what LDH is in a biochemical blood test is associated primarily with myocardial infarction. Previously, this test was used to diagnose and monitor damage to cardiac tissue, but now the troponin test is considered more accurate and informative. Lactate dehydrogenase (LDH) is not a specific indicator of heart cell damage and is no longer used in patients with suspected acute coronary syndrome. Usually, the decoding of a biochemical blood test contains this indicator. Lactate dehydrogenase in the blood is an important enzyme involved in the reactions:

Glucose oxidation;

Production of lactic acid.

A feature of the enzyme is that it does not accumulate in cells, but is completely cleaved and excreted. LDH is needed to convert glucose into energy for the life of all cells in the body. The mediator of the reaction is oxygen, which helps to break down glucose into water, carbon dioxide and energy. Without oxygen, energy production decreases by a factor of 20 and lactic acid builds up. The enzyme LDH is necessary for its oxidation and return to glucose metabolism. Unlike healthy cells, cancerous tumors feed without oxygen.

When is an analysis ordered?

The test is used for suspected acute and chronic tissue damage, as well as for assessing progressive diseases. In rare cases, the analysis helps to identify the target organ damage.

The enzyme is determined in a venous blood sample. After an injury, LDH is elevated, rises over 48 hours and reaches a maximum after 2-3 days, then gradually decreases. The normal indicator is restored in 10 days.

Studies show that a biochemical blood test for LDH is an indicator of the development and progress of cancer. Even after taking into account the factor of age, stage of the disease in patients, a strong association with the risk of death persisted. This relationship was true for all types of malignant tumors.

An LDH blood test can be used to detect and evaluate:

Acute or chronic tissue damage;

Progression of anemia and severe infection;

The course of oncological diseases after chemotherapy, leukemia, melanoma, neuroblastoma. High values ​​indicate poor prognosis of patient survival.

The doctor prescribes the determination of the level of LDH in other body fluids:

To distinguish between bacterial and viral meningitis by analysis of cerebrospinal fluid.

To identify the cause of the accumulation of exudate in the chest or abdomen (pleural, peritoneal and pericardial fluids) due to trauma and inflammation or due to an imbalance of pressure within the blood vessels and the amount of protein in the blood.

A blood test for LDH (biochemistry) is taken on an empty stomach from a vein.

The last meal 8 hours before the examination should not contain too fatty and protein foods.

Be sure to tell if you need to take medications regularly. Aspirin, hormonal contraceptives, and antidepressants affect clotting and may show elevated values.

Intensive training the day before can lead to an increase in the enzyme, as it increases energy expenditure and the need to break down glucose.

Many factors affect the results of the analysis, and they are not always a cause for concern and further examination:

Blood sampling leads to false positive results. Violation of the rules for storing samples, rough processing affect accuracy.

With an increased number of platelets, the serum level of LDH also rises and does not show a real picture.

When hospitalized with suspected myocardial infarction and acute pancreatitis, LDH analysis is performed without taking into account recommendations. Often, the LDH indicator is used to assess the dynamics of the disease and the patient's recovery.

Norm of LDH in the body and decoding of the analysis

When analyzing blood, the norm is usually indicated in units / l, which means one per liter. The decoding of the analysis takes into account the age and gender of the patient. In the blood of a healthy adult, a relatively small amount of the enzyme is found. In a child under two years old, an indicator within 430 units / l is considered the norm.

An increase in lactate dehydrogenase occurs during pregnancy, in newborns, and in professional athletes.

Based on the identified marker, it is impossible to determine which cells were damaged. Therefore, it is necessary to know when deciphering LDH, what are its isoenzymes. Some laboratories conduct additional tests that determine several forms of a substance, starting with the most mobile:

The first indicates a problem with the heart, kidneys, and red blood cells;

The second is found mainly in cardiomyocytes and erythrocytes;

The third is found in the tissues of the lungs, endocrine glands and adrenal glands;

the fourth is an enzyme in white blood cells, liver, placenta and male testicles and muscle tissue;

The fifth is found in all organs containing LDH-4, as well as skeletal muscles.

Deciphering biochemistry for an increase in LDH in the blood is now considered less informative.

High values ​​of all isoenzymes determine the pathology of several organs. Myocardial infarction with congestive heart failure causes lung damage and liver congestion. In cancers and autoimmune diseases such as lupus, lactate dehydrogenase is generally elevated. Hypoxia, shock, and burns are accompanied by cell death, which indicates an increase in LDH. Caffeine also affects the amount of the enzyme in the blood.

The dynamics of the first isoenzyme is more sensitive and specific than the increase in LDH in general. Usually the level of the second isoenzyme is higher than the first. If the concentration of LDH-1 rises relative to LDH-2, a heart attack is diagnosed. Usually, the norm of LDH in the blood is exceeded 12-24 hours after damage to the heart tissue and for two days in 80% of cases. A normal LDH-1/LDH-2 ratio is reliable evidence that there was no attack. The ratio of total LDH and LDH-1 is called hydroxybutyrate dehydrogenase. Therefore, with a heart attack:

The figure LDH / HBDG is lowered (less than 1.30);

The LDH-1/LDG-2 ratio approaches 1 and sometimes exceeds this value.

On the first day, myocardial infarction is diagnosed in terms of creatine kinase, and a day later, according to the enzymatic study of LDH. The activity of the substance is directly related to the area of ​​damage to the heart muscle.

Other severe diseases reflect on the ratio of isoenzymes and coefficients:

Hemolytic anemia is characterized by low LDH / HBDG - up to 1.3 and below;

In megaloblastic anemia, LDH-1 is significantly higher than LDH-2;

the overall level increases with acute necrotic processes and cell death, such as damage to the kidney parenchyma;

tumors in the sex glands (ovaries and testicles) are accompanied by an isolated increase in LDH-1.

Most often, LDH is elevated due to the destruction of the tissues of the hepatic and renal parenchyma, and the death of platelets and erythrocytes.

LDH in a blood test is considered in relation to other indicators:

In anemia, red blood cells are destroyed, which releases large amounts of LDH into the blood. The disease is diagnosed against the background of low hemoglobin. Weakness, pallor, shortness of breath may be indications for examination.

Blood cancer is associated with the production of abnormal blood cells, which is reflected in the levels of many indicators: LDH, aspartate aminotransferase, bilirubin, urea. At the same time, there is a decrease in the level of glucose and the blood coagulation factor fibrinogen. A biochemical blood test allows you to suspect a pathology and refer the patient to identify tumor markers.

Along with the LDH indicator in the blood, which indicates the death of pancreatic cells, bilirubin and glucose will increase. The primary indicator is the level of the pancreatic enzyme amylase.

Reasons for the increase

Elevated levels of LDH can be caused by various diseases:

• stroke;
• some types of anemia (pernicious and hemolytic)
• kidney and liver diseases;
• muscular dystrophy;
• pancreatitis;
• Infectious mononucleosis;
• some forms of cancer.

The concentration of the enzyme increases after the introduction of anesthetics and taking aspirin, as well as after intense physical exertion. Normal and low LDH levels are not pathological. A factor that reduces the rate is the consumption of a large dose of ascorbic acid (vitamin C).

The reasons that lactate dehydrogenase is elevated are varied: HIV infection, sepsis, acute kidney disease, infarction of the intestines and lungs, bone fractures, rash on the body.

LDH is low when transudate accumulates in body cavities, such as the abdomen, which is usually caused by congestive heart failure or cirrhosis.

Laboratory blood tests are informative methods of primary diagnosis. According to their results, possible violations in the work of organs and body systems are evaluated. The study of LDH in a biochemical blood test is primarily aimed at determining hematological, cardiac, muscle and oncological pathologies.

Basic concepts and functions of LDH

LDH (lactate dehydrogenase) is an oxidoreductase enzyme that accelerates the formation of lactic acid during glycolysis (glucose oxidation). Like most catalysts, lactate dehydrogenase does not accumulate in cells, but is excreted from the body in an amount equivalent to that formed.

The highest concentration of the enzyme is noted in the parenchyma of the liver and kidneys, in the tissues of the muscular apparatus and heart. Each area of ​​localization corresponds to its own isoenzyme (a type of LDH). A small amount of lactate dehydrogenase is found in red blood cells (erythrocytes).

An increase in the level of the enzyme in the blood occurs during the destruction of LDH-containing cells. Assessing the type of elevated isoenzyme in the course of biochemistry, the location of the damage is determined, that is, the organ whose cells have been destroyed. Enzyme isoforms are numbered from 1 to 5, depending on their location:

The increased activity of one or another type of lactate dehydrogenase is a marker of the destructive transformation of the tissue of the organs in which it is contained. With a standard biochemical analysis, the form usually indicates the total indicator of LDH.

If necessary, an extended study is carried out, with an assessment of each individual isoform of the enzyme (Sevel-Tovarek test, methods of inactivation with urea and thermal inhibition). In the blood of a healthy person, LDH is static and has certain reference values.

Important! An altered concentration of lactate dehydrogenase does not diagnose a specific disease. The obtained values ​​are compared with other indicators of biochemical analysis. Unsatisfactory results are the basis for an additional examination of a particular system or organ.

Indications for research

Blood biochemistry is prescribed:

• according to the symptomatic complaints of the patient;
• during a routine check (medical examination, screening of pregnant women, IHC, etc.);
• to control the ongoing therapy;
• in preparation for surgery.

Increased attention to LDH indicators in a blood test is given in case of a presumptive diagnosis:

• anemia (anemia);
• ischemic necrosis of a part of the myocardium (heart attack);
• cirrhosis, hepatitis, liver carcinoma (cancer);
• oncohematological diseases (cancerous tumors of the blood and lymphoid tissue);
• blood poisoning (sepsis);
• severe intoxication, accompanied by the destruction of red blood cells (erythrocyte hemolysis);
• necrotic processes, and mechanical damage to internal organs.

The biochemical composition of the blood is checked after the course use of chemotherapeutic drugs. For differentiated diagnosis of some bacterial and viral infections, the determination of the level of LDH is carried out by analyzing the cerebrospinal fluid (cerebrospinal fluid).

Blood analysis

To obtain objective results, blood should be taken on an empty stomach. The fasting regimen should be from 8 to 10 hours. On the eve of the analysis it is recommended:

• limit sports (other physical) activities;
• eliminate fatty foods from the diet (sausages, mayonnaise sauces, pork, lamb, etc.) and fried foods;
• exclude alcoholic drinks;
• refuse coffee;
• stop taking anticoagulants, hormone-containing drugs, ascorbic acid.

Venous blood sampling is performed in the morning in the laboratory

Blood for analysis is taken from a vein. Decoding is carried out by comparing the obtained indicators with reference values. The results of the study will be available in a day. If an emergency laboratory assessment of the LDH level is required (acute conditions), the blood is examined without prior preparation.

Standard values

Reference Enzyme Concentrations for Children and Adolescents (in U/L)

In women, the norm of LDH in the blood is less than in men, which is due to less intense physical activity. Female normative values ​​range from 135 to 214 U / l, male - from 135 to 225 U / l. A slight excess of reference values ​​is observed in professional athletes and pregnant women.

The deviation of the values ​​of enzymatic activity in the direction of increasing or decreasing indicators is the basis for extended diagnostics (laboratory tests and hardware examination of the patient).

Reasons for deviations

In most cases, an unsatisfactory result of a biochemical blood test for LDH means an increase in the concentration of the enzyme. This is explained by the fact that with a destructive violation of the integrity of the cellular structure of an organ, a significant part of lactate dehydrogenase enters the bloodstream. An extremely reduced level of the enzyme or its complete absence is observed in the decompensated stage of liver cancer and cirrhosis.

Increased rate

Elevated LDH is one of the main clinical and diagnostic indicators of myocardial infarction. The enzyme reaches its maximum activity in the first 24 hours from the onset of a heart attack and remains at an increased concentration for 1–2 weeks. At the same time, the duration and degree of activity reflect the extent of necrotic damage to the heart muscle (values ​​can increase tenfold).

The total LDH is elevated due to a sharp increase in the concentration of isoenzyme No. 1, localized in the myocardium. To obtain an accurate picture, the ratio of the total content of lactate dehydrogenase to the amount of isoenzyme No. 1 is estimated, otherwise - hydroxybutyrate dehydrogenase (HBDG). In the acute course, HBDG is always increased, since the total amount of the enzyme is reduced in relation to the high concentration of isoenzyme No. 1.

Myocardial infarction is accompanied by an increase in LDH

The growth of indicators accompanies any pathological processes characterized by the death of cells and tissues. In addition to necrotic damage to the heart muscle, the reasons for the increased content of LDH can be:

• Blockage of the lumen of the pulmonary artery by a blood clot that has budded from the main thrombus located in a large vein (pulmonary embolism).
• Malignant neoplasms of various localization (liver, kidneys, etc.), and secondary tumor foci (metastases).
• Oncohematology.
• Anemia (anemia) of various origins associated with hemolysis of red blood cells. Hemolytic anemia is associated with poisoning of the body with heavy metals or with incorrectly performed blood transfusion (blood transfusion). Addison-Birmer disease or pernicious anemia develops due to a lack of cyanocobalamin (vitamin B 12) in the body.
• Liver diseases associated with the death of hepatocytes.
• Destructive-degenerative processes in muscle fibers, muscle atrophy, traumatic damage to muscle tissue.
• Inflammation of the tubular system of the renal apparatus, damage to the glomeruli (glomeruli of the kidneys), otherwise glomerulonephritis, kidney necrosis.
• Viral damage to the lymph nodes, pharynx, liver, spleen (mononucleosis).
• Acute inflammation of the pancreas (pancreatitis).
• Termination of functionality (death) of pancreatic cells (pancreatic necrosis).
• Death of the intestinal wall due to insufficient blood supply (intestinal infarction).
• Bone fractures.
• Pathology of the thyroid gland, in which the synthesis of hormones is reduced (hypothyroidism).
• Acute symptomatic convulsive attack;
• Metal-alcohol psychosis ("white tremens").
• Severe preeclampsia (pathological toxicosis in the second half of pregnancy).
• Extensive burns of the skin.
• Infectious-toxic inflammation of the lungs (pneumocystis pneumonia).
• Early separation of the provisional organ from the walls of the uterus (premature placental abruption).
• Violation of the coronary blood flow (coronary insufficiency);
• Heart disease in the decompensated stage.
• Necrotic damage to a part of a living organism (gangrene).

Chemotherapy causes a natural increase in LDH. An aggressive treatment method kills not only pathological cells, but also destroys some healthy ones.

Reduced rate

The state of low lactate dehydrogenase is much less common. First of all, incorrect therapy with ascorbic acid preparations, anticonvulsant and antitumor drugs, antibiotics, hormonal drugs is assumed.

The reasons for lowering the level of the enzyme can be a violation of pH (acidity) due to the presence of salts of oxalic acid (oxalates), genetic abnormalities. When the values ​​fall, the patient is canceled medications (except for vital ones).

Important! LDH levels in the blood can change not only due to cell destruction, but also for non-pathological reasons.

Non-pathological change in indicators

Factors that skew the results include:

• non-compliance with the rules of preparation for blood sampling for LDH;
• intensive sports training;
• physical or psycho-emotional overload on the eve of analysis;
• thrombocytosis - an abnormal increase in platelets (platelets) in the blood;
• acute and chronic skin diseases;
• extrarenal blood purification by hemodialysis;
• perinatal period in women.

The medical reason for unreliable results may be incorrect blood sampling and biomaterial examination.

Additionally

To reduce the level of the enzyme, it is first necessary to diagnose the underlying disease that caused the change in LDH concentration. Auxiliary diagnostics include:

• laboratory blood test to determine the content of enzymes:
• hepatic and cardiac - ALT and AST (alanine aminotransferase and aspartate aminotransferase);
• muscle - CPK (creatine phosphokinase);
• ALP (alkaline phosphatase).
• a blood test for the globular protein troponin and the oxygen-binding protein myoglobin.
• advanced analysis to determine the concentration of all isoenzymes.

With a comparative assessment of all indicators, a hardware examination of internal organs (ultrasound, MRI, CT and other procedures, depending on the alleged location of the violations) is prescribed.

Results

Lactate dehydrogenase is an enzyme that acts as a catalyst for the oxidation of glucose and the formation of lactic acid. The main amount of LDH is concentrated in the renal, hepatic, cardiac tissues and muscle fibers. A specific isoenzyme (a type of LDH) is responsible for each organ.

Normative values ​​of blood levels in adults

Children's indicators are graded by age category. If a biochemical analysis determines an increased activity of lactate dehydrogenase in the blood, then the integrity of the parenchyma of the liver, kidneys, myocardium (heart muscle) is violated. With a devastating lesion of these organs, the enzyme is released through the affected areas into the systemic circulation.

High rates are clinical signs of infarction, cirrhosis, cancerous tumors, pancreatic necrosis, pulmonary thromboembolism, diseases of the renal apparatus and other pathologies associated with tissue destruction and the death of cellular structures. According to the results of the study, a specific disease is not diagnosed. The shift in indicators is the basis for an extensive examination of the patient.