If LDH is elevated in the liver, what to do. Ldg in the blood is elevated causes symptoms and treatment. Causes of increased lactate dehydrogenase

In today's world, science does not stand still. Diseases are carefully studied, and scientists are looking for ways to combat them. Doctors are often prescribed to take tests that are not at all clear to ordinary people, but it can confirm or refute the doctor's fears. So the analysis for LDH, and especially increased lactate dehydrogenase, says a lot. What is it, and what are the consequences, we will talk further.

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.

Types of LDH

The enzyme lactate dehydrogenase has several forms that differ from each other by isoenzymes, and they are found in different tissues. Depending on the greater concentration of the isoenzyme in a particular organ, there are types of this enzyme:

LDH-1 - predominantly in the heart and blood cells.
2 - in leukocytes.
3 - in lung tissue.
LDH - 4 - most of all in the kidneys, placenta, pancreas.
5 - found in the liver and striated muscle tissue.

Thanks to this, it is possible to draw a conclusion, due to which isoenzyme the level of LDH is increased, and to determine the disease.

When is this test ordered?

There are several conditions in which it is necessary to control the level of LDH:

For diseases
after myocardial infarction.
When detecting various tumors.
If necessary, determine the type of anemia.
In diseases with increased hemolysis.
With sharp pains in the chest area.
If there is damage to the liver or kidneys.
To examine tissues and muscles after injury or disease.

Influence of factors on the result of the analysis

If the doctor suspects that you have elevated lactate dehydrogenase, only an analysis can refute or confirm this.

A blood test for LDH is taken in the morning on an empty stomach. Blood is taken from a vein. There is no special diet required before the trip. It is only necessary to know that there are factors that can distort the result. What can affect the accuracy of the analysis result:

Taking vitamin C can lower blood levels of LDH.
The use of electropulse therapy on the eve of the test.
Skin problems.
The content of alcohol in the blood.
Thrombocytosis.
The use of hemodialysis.
Some medications, such as Aspirin, Mithramycin, anesthetics, fluorides, can increase the level of the enzyme.
Excessive physical activity.

These factors can affect the result, but this does not mean that there are pathological processes in the body.

Before you find out the content of the enzyme in your blood, you should consult with your doctor about which drugs should be discontinued before going to the laboratory.

It is very important to properly transport and store the collected blood, as failure to comply with the rules can lead to and as a result increased lactate dehydrogenase.

LDH norm indicators for children and adults

Lactate dehydrogenase levels change with age. The older a person gets, the lower they are. So, the concentration of LDH:

Newborns - up to 28.9 microkat / l.
From 1 year to 3 years - up to 14.2 microkat / l.
In boys from 7 to 12 years old - up to 12.7 mkat / l.
Girls from 7 to 12 years old - up to 9.67 mkat / l.
Men - up to 11.4 microkat / l.
Women - up to 7.27 microkat / l.

LDH levels may be higher or lower than normal.

Increased lactate dehydrogenase - causes

Increased rates are observed in pregnant women and with excessive physical exertion.

If, as a result of the analysis, lactate dehydrogenase is increased. The reasons for this are the development of the following conditions:

Myocardial infarction.
Viral diseases of the liver.
Cirrhosis of the liver.
Oncology.
Acute pancreatitis.
Pathological diseases of the kidneys.
Anemia.
Leukemia.
Conditions in which extensive cell breakdown occurs: shock, severe hypoxia, burns of large areas.
Extensive trauma.
Diseases of the muscular system.

However, not only this analysis confirms the presence of pathology in the body. Further investigation is needed. By studying the activity of isoenzymes, a specialist will be able to determine the localization of the disease.

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.
megaloblastic.
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.

LDH in children

If the first result is higher than normal, it is necessary to retake the analysis to make sure it is accurate. If, nevertheless, lactate dehydrogenase is elevated in a child, then a complete examination is necessary. This indicator alone does not give the right to make a final diagnosis and prescribe treatment.

Treatment of diseases and changes in LDH

If lactate dehydrogenase is elevated, treatment of the disease can gradually bring this indicator back to normal.

If at the beginning of the disease lactate dehydrogenase is increased, then with successful leukemia, tumor diseases, LDH activity decreases.

Here is such a not quite simple analysis, which most of us do not even know about. And he, it turns out, can tell a lot about the attending physician.

LDH blood test is lactate dehydrogenase (LDH)- an enzyme contained in the cells of the heart muscle, liver, kidneys, lungs, skeletal muscles. In this regard, in clinical practice, separate isoenzymes are isolated: LDH1 and LDH2 (found mainly in the myocardium, kidneys), LDH3 (found mainly in the lung tissue), LDH4 and LDH5 (determined in the largest quantities in the liver and skeletal muscles), the information content of which higher than when determining the total LDH.

Raise LDH (especially LDH1 and LDH2) is most often observed in acute myocardial infarction, while in angina pectoris (including unstable), this indicator remains normal, which allows it to be used along with creatine kinase (for details, see the item “creatine kinase” and “creatine kinase MB ”) for the differential diagnosis of these conditions with a dubious ECG picture. A moderate increase in LDH is also observed in patients with acute myocarditis, severe heart failure with congestion in the liver, as well as in the development of pulmonary embolism. A significant increase in both total LDH and its isoenzymes LDH4 and LDH5 is observed in acute hepatitis, cirrhosis of the liver in the acute stage, as well as in cancerous lesions of the liver. LDH activity also increases with obstructive jaundice (most often with blockage of the bile ducts by a stone or compression by a tumor) and hemolytic anemia. A moderate increase in this indicator is possible with extensive traumatic muscle injuries and with progressive muscular dystrophy.

decline LDH activity in clinical practice does not matter.

biological material: blood serum

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 activity of LDH can be detected in newborns, pregnant women and after intense physical exertion.

Monitoring the course of myocardial infarction. An increase in LDH activity is observed at 12 - 24 hours after a heart attack; maximum activity is observed after 24 - 48 hours. Increased enzyme activity lasts up to 10 days. LDH activity depends on the size of the myocardial lesion, and the dynamics of its decrease in the process of recovery depends on the intensity of regenerative processes in the heart muscle.

Determination of LDH activity makes it possible to differentiate true myocardial infarction and clinically similar angina attacks: with a heart attack, the total LDH activity increases and, as a result, its value is several times higher than the normal level, while at the same time, even with severe angina attacks, the level of LDH activity is normal. The decrease in enzyme activity in the postinfarction period occurs 2 times slower than the normalization of such markers of myocardial damage as creatine kinase and AST, which is especially valuable for the late diagnosis of damage.

Indications for the appointment of the study

1. Diseases of the hepatobiliary system;
2. Myocardial infarction (early diagnosis, differential diagnosis and monitoring);
3. Tumors;
4. Anemia, accompanied by hemolysis.

Study preparation

GENERAL RULES OF PREPARATION FOR RESEARCH:

1. For most studies, it is recommended to donate blood in the morning, between 8 a.m. and 11 a.m., on an empty stomach (at least 8 hours should elapse between the last meal and blood sampling, you can drink water as usual), on the eve of the study, a light dinner with a restriction eating fatty foods. For infection tests and emergency investigations, it is acceptable to donate blood 4-6 hours after the last meal.

2. ATTENTION! Special rules for preparing for a number of tests: strictly on an empty stomach, after 12-14 hours of fasting, you should donate blood for gastrin-17, lipid profile (total cholesterol, HDL cholesterol, LDL cholesterol, VLDL cholesterol, triglycerides, lipoprotein (a), apolipo-proten A1, apolipoprotein B); a glucose tolerance test is performed in the morning on an empty stomach after 12-16 hours of fasting.

3. On the eve of the study (within 24 hours), exclude alcohol, intense physical activity, medication (as agreed with the doctor).

4. 1-2 hours before donating blood, refrain from smoking, do not drink juice, tea, coffee, you can drink non-carbonated water. Eliminate physical stress (running, fast climbing stairs), emotional arousal. It is recommended to rest and calm down 15 minutes before donating blood.

5. You should not donate blood for laboratory testing immediately after physiotherapy procedures, instrumental examinations, X-ray and ultrasound examinations, massage and other medical procedures.

6. When monitoring laboratory parameters in dynamics, it is recommended to conduct repeated studies under the same conditions - in the same laboratory, donate blood at the same time of day, etc.

7. Blood for research should be donated before the start of taking medications or no earlier than 10-14 days after they are discontinued. To evaluate the control of the effectiveness of treatment with any drugs, it is necessary to conduct a study 7-14 days after the last dose of the drug.

If you are taking medication, be sure to tell your doctor about it.

General information about LDH

Lactate dehydrogenase (LDH) is an important intracellular, zinc-containing enzyme that is present in most organs and tissues. An increase or decrease in the amount of lactate dehydrogenase and its multiple isoenzymes may indicate damage to the integrity or destructive changes in the organs in which they are located.

The main biochemical function of LDH in the human body is the conversion of lactic acid into pyruvic acid. This is due to the specific structure of the enzyme, which allows the hydroxyl group to be cleaved from the lactate molecule, followed by the formation of pyruvate. Pyruvic acid is the key to the tricarboxylic acid cycle, also known as the Krebs cycle. The Krebs cycle is the most important stage in the respiratory processes of almost all cells that use oxygen.

Lactic acid is a dangerous and numerous metabolite in the body. Thanks to the enzyme LDH, lactate is used to break down glucose, which then produces a large amount of energy. The generated energy is used by the body to carry out vital biochemical reactions and muscle contraction, resulting in the formation of lactic acid.

With a lack of oxygen in the human body, the reverse transformation of lactate into pyruvic acid can occur. In yeast, which are anaerobic organisms, lactate is converted into ethyl alcohol. This phenomenon is known as fermentation and is actively used in industry and everyday life.

If there is an insufficient amount of oxygen in the human body, the enzyme lactate dehydrogenase accumulates, which leads to fatal changes in cell metabolism and disruption of the integrity of its membrane. The release of the contents of the cell into the bloodstream leads to an increase in the amount of LDH, which doctors will detect in a biochemical blood test. Lactate dehydrogenase is one of the most important indicators of cell destruction of tissues and organs in which it is located.

Types of LDH

LDH-1. Found in heart muscle and brain cells
LDH-2. Localized in the tissues of the kidney and spleen
LDH-3. Most commonly found in the lungs, thyroid gland, pancreas, and adrenal glands
LDH-4. Is characteristic of the placenta and male sex hormones
LDH-5. Marker of destructive lesions of muscle tissue and liver.

Most often, the first isoenzyme is found in acute myocardial injury, known as a heart attack. These phenomena are used to diagnose myocardial infarction, which helps to significantly reduce mortality. With myocardial infarction, LDH-1 rises after 12-16 hours.

Currently, troponin tests are used for the rapid diagnosis of myocardial damage. They are more specific and appear faster in the blood. Troponin tests become positive in the first hours after the onset of necrotic changes in the heart muscle.

An increase in the number of isoenzymes 2, 3 and 4 in the bloodstream will indicate not only destructive changes in the relevant organs, but also a massive death of platelets. These changes may indicate that the patient has pulmonary embolism. Since the mortality in PE is very high, timely diagnosis will help save the patient's life.

An increase in the amount of the fifth isoenzyme of lactate dehydrogenase (LDH) in most cases occurs in the acute phase of viral hepatitis.

How is LDH determined?

To determine LDH and its isoenzymes, the patient's venous blood is examined. There is no special preparation for donating blood for LDH, since this indicator is not specific.

To conduct an adequate study, doctors recommend several general rules:

Blood sampling from the patient is done on an empty stomach. It is desirable that the procedure was carried out before 10-11 am. A specific diet does not need to be followed. It is necessary not to eat 8 hours before the proposed trip to the hospital. If this rule is violated, then the blood will clot and will be unsuitable for further research.
Stop smoking the day before the test
A few days before going to the laboratory, you must refuse to take alcoholic beverages. Alcohol affects the coagulation and rheological properties of blood. Also, when drinking alcohol, the amount of LDH-5 increases, due to necrosis of liver cells.
On the day of blood donation, you should refuse to take medicines. Acetylsalicylic acid, contraceptives, antidepressants can significantly change the coagulation properties of the blood, which will make it impossible to conduct a study. If the patient has taken some medicine, he should inform the doctor about it. Most likely, medical staff will reschedule the blood draw to another day.
Significant physical activity on the eve of the study significantly changes blood counts, which leads to an inadequate result.

Which specialist pays attention to this parameter?

Studies of lactate dehydrogenase is not a specific indicator of the disease. This analysis is used as an auxiliary and indicates cell destruction or an inflammatory process. The internist, oncologist, cardiologist and general practitioner - family medicine can prescribe this analysis if you suspect the development of the disease based on symptoms and anamnesis.

In such cases, the doctor prescribes lactate dehydrogenase studies:

With pain of a different nature behind the sternum. Used as a differential parameter. Such pains can cause pulmonary infarction, myocardial infarction, angina pectoris and calmness, gastroesophageal reflex disease. Increases in the first isoenzyme will indicate the development of a myocardial infarction in a patient
In malignant tumors, the oncologist prescribes this analysis to monitor the dynamics of the development and course of the disease. Also, a decrease in the LDH enzyme will indicate the success of treatment and the regression of the tumor process. Not so long ago, scientists synthesized a substance that blocks the production of lactate dehydrogenase. This leads to the accumulation of lactic acid inside the cell and its death. If this substance is introduced into the location of the development of the tumor process, then the cancer cells will die. It has been experimentally proven that such a drug is effective only in the first stages of the development of the tumor process.
When staging previously diagnosed diseases of the kidneys and liver
When analyzing the state of muscle tissue
When monitoring the condition of a patient with chronic diseases
When examining the whole body for preventive purposes
To determine the type of anemia

LDH values

Based on changes in the concentration of LDH in the blood, it is impossible to make a diagnosis. Only a doctor can interpret and draw any conclusions. The normal concentration of LDH in the blood depends on the age, gender and condition of the patient. Doctors in their work use the following reference values:

From the birth of a child to the first year, this parameter is 451 units per liter
From the first to the third year of life, this value is 344 units per liter
From 3 to 6 years, the norm will correspond to 314 units per liter
At 6-12 years old, the norm is 332 units per liter
From 12 to 17 years old, the norm will be in the range of 279 units per liter
17 years and older, the reference value of the norm is already distributed depending on the sex of the subject. For male patients, these values will be at the level of 135-225 units per liter. For the female - 135-214 units per liter

For pregnant women and professional athletes, LDH reference values are higher than in the general population.

Changes in LDH levels in the bloodstream

The cause of an increase in the amount of lactate dehydrogenase in the blood may be the following pathological conditions:

myocardial infarction
Viral hepatosis
Cirrhotic changes in the liver
Oncological diseases
Acute pancreatitis
kidney disease
anemia
Traumatic injuries
Muscle tissue disease
Functional disorders of the cardiovascular and respiratory systems
Lymphoma
Leukemia
Myositis and polymyositis
Inflammation of the lungs
Phlebothrombosis of the lower limb
AIDS virus
Sepsis
Acute necrotic process

The amount of lactate dehydrogenase decreases with successful treatment of oncological pathology, hemolytic anemia, and lymphomas. LDH also decreases if the patient has oxalates, urea, and a specific inhibitory enzyme. If the patient took medication before the study, the result will be underestimated. These drugs include: amikacin, ascorbic acid, hydroxyurea, dofibrate, captopril, prednisolone, naltrexone, cefotoxime, antispasmodics.

LDH in cerebrospinal fluid and pleural effusion

An increase in the amount of the enzyme lactate dehydrogenase in the pleural effusion helps doctors differentiate between exudate and transudate. If this figure is more than twice, then this indicates in favor of the exudate, and if it is lower, then this is a transudate. With pleural empyema, the amount of lactate dehydrogenase rises to 1000 units per liter.

In the cerebrospinal fluid, an increase in LDH is found in bacterial meningitis.

Conclusion

The value of the determination of LDH in the blood is not high, due to its low specificity. LDH rises in diseases of the kidneys, liver, heart and characterizes the destruction of their cells.

An analysis for LDH can lead to the idea of \u200b\u200bthe disease. It is impossible to make a diagnosis without additional studies.

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.

It is with the help of this classification that doctors quickly determine in which organ tissue deformation occurs, which greatly simplifies the diagnosis of pathological conditions.

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.

Fraction	Serum quantitation % (relative units)
LDH-1	17 – 27% (0,17 – 0,27)
LDH-2	27 – 37% (0,27 – 0,37)
LDH-3	18 – 25% (0,18 – 0,25)
LDH-4	3 – 8% (0,03 – 0,08)
LDH-5	0 – 5% (0,00 – 0,05)

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. .

For an accurate interpretation, you need to drown these factors directly in the place where the analysis 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;

myoglobin

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.

The interpretation of the analysis should be entrusted to a qualified doctor.

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.

Hydroxybutyrate dehydrogenase

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:

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.
Myocardial infarction. If the heart muscle is destroyed, then the indicator has quite high values.
Oncological pathologies.
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:

Myocardial infarction in the acute phase.
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.
Inflammation of the lungs, hepatic and renal parenchyma.
Hemolytic and pernicious anemia.
, pulmonary embolism.
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.
Tumor formations of a malignant nature, in particular, with metastases, the localization of which is the liver.
Hematological diseases, for example, granulocytosis, anemia, the development of which was preceded by a lack of vitamin B12 or folic acid deficiency.
Massive platelet destruction. The main reason for this pathological condition is blood transfusion.
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:

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.
If the increase in the concentration of the enzyme was provoked by iron deficiency anemia, then the doctor prescribes a special diet, which includes the use of foods that contain Fe and vitamin C, special medications that restore the norm of this element, and walks.
For oncological diseases, complex treatment is carried out, which includes the use of special drugs, chemotherapy and radiation therapy.
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 heart 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 due to the fact that 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.

In today's world, science does not stand still. Diseases are carefully studied, and scientists are looking for ways to combat them. Doctors are often ordered to take tests that are not at all clear to ordinary people, but it is this result that can confirm or refute the doctor's fears. So the analysis for LDH, and especially increased lactate dehydrogenase, says a lot. What is it, and what are the consequences, we will talk further.

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.

Types of LDH

LDH-1 - predominantly in the heart and blood cells.
2 - in leukocytes.
3 - in lung tissue.
LDH - 4 - most of all in the kidneys, placenta, pancreas.
5 - found in the liver and striated muscle tissue.

Thanks to this, it is possible to draw a conclusion, due to which isoenzyme the level of LDH is increased, and to determine the disease.

When is this test ordered?

There are several conditions in which it is necessary to control the level of LDH:

In diseases of the hepatobiliary system.
after myocardial infarction.
When detecting various tumors.
If necessary, determine the type of anemia.
In diseases with increased hemolysis.
With sharp pains in the chest area.
If there is damage to the liver or kidneys.
To examine tissues and muscles after injury or disease.

Influence of factors on the result of the analysis

If the doctor suspects that you have elevated lactate dehydrogenase, only an analysis can refute or confirm this.

A blood test for LDH is taken in the morning on an empty stomach. Blood is taken from a vein. Before going to the treatment room, no special diet is required. It is only necessary to know that there are factors that can distort the result. What can affect the accuracy of the analysis result:

Taking vitamin C can lower blood levels of LDH.
The use of electropulse therapy on the eve of the test.
Skin problems.
The content of alcohol in the blood.
Thrombocytosis.
The use of hemodialysis.
Some medications, such as Aspirin, Mithramycin, anesthetics, fluorides, can increase the level of the enzyme.
Excessive physical activity.

These factors can affect the result, but this does not mean that there are pathological processes in the body.

Before you find out the content of the enzyme in your blood, you should consult with your doctor about which drugs should be discontinued before going to the laboratory.

It is very important to properly transport and store the collected blood, as failure to follow the rules can lead to hemolysis of the blood, and as a result, increased lactate dehydrogenase.

LDH norm indicators for children and adults

Lactate dehydrogenase levels change with age. The older a person gets, the lower they are. So, the concentration of LDH:

Newborns - up to 28.9 microkat / l.
From 1 year to 3 years - up to 14.2 microkat / l.
In boys from 7 to 12 years old - up to 12.7 mkat / l.
Girls from 7 to 12 years old - up to 9.67 mkat / l.
Men - up to 11.4 microkat / l.
Women - up to 7.27 microkat / l.

LDH levels may be higher or lower than normal.

Increased lactate dehydrogenase - causes

Increased rates are observed in pregnant women and with excessive physical exertion.

If, as a result of the analysis, lactate dehydrogenase is increased. The reasons for this are the development of the following conditions:

Myocardial infarction.
Viral diseases of the liver.
Cirrhosis of the liver.
Oncology.
Acute pancreatitis.
Pathological diseases of the kidneys.
Anemia.
Leukemia.
Conditions in which extensive cell breakdown occurs: shock, severe hypoxia, burns of large areas.
Extensive trauma.
Diseases of the muscular system.

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.

LDH in children

If we talk about children, then the age of the child should be taken into account. In children, LDH levels are higher. Also, before you go to the doctor, you need to track what drugs the child is taking and monitor his physical activity. If lactate dehydrogenase is elevated in a child, the causes may be caused by one of the pathologies described above. It should be borne in mind that if the baby is allergic, this can also affect the result, especially with severe childhood eczema or bronchial asthma. Injuries and bruises can distort the analysis, as well as the presence of anemia in a child.

Treatment of diseases and changes in LDH

If lactate dehydrogenase is elevated, treatment of the disease can gradually bring this indicator back to normal.

If at the beginning of the disease lactate dehydrogenase is increased, then with the successful treatment of anemia, leukemia, tumor diseases, LDH activity decreases.

Here is such a not quite simple analysis, which most of us do not even know about. And he, it turns out, can tell a lot about the attending physician.

Blood lactate dehydrogenase (LDH) is a laboratory test with low specificity. However, its deviation from the norm is a sufficient condition for a comprehensive examination of the patient. It is necessary for the primary diagnosis of pathologies in the work of the heart, lungs, kidneys, various oncopathologies and destruction of muscle tissue in humans.

What is LDH in the blood?

In order to understand the purpose for which the analysis is prescribed, you should first understand - what is LDH in a biochemical blood test?

Lactate dehydrogenase (LDH) in the blood is an enzyme localized inside cells. The composition necessarily includes zinc ions. Its main function is to catalyze the oxidation of lactic acid to pyruvate. Almost all cells in the human body contain the enzyme LDH. The maximum concentration is observed in skeletal (9000 units/g) and cardiac (25000 units/g) muscles, as well as in the kidneys (15000 units/g), lungs (9500 units/g) and liver (9000 units/g).

In case of cell damage, an active release of the enzyme into the bloodstream occurs. Blood cells also contain LDH, however, their content is negligible. That is why even with a slight destruction of the tissues of any of the organs, there is a sharp increase in the level of LDH in the blood serum, which is used to diagnose various diseases. This fact makes it possible to attribute the blood test for LDH to highly sensitive, but low specific criteria.

Enzyme isoforms

From the point of view of the information content of the obtained results, LDH isoforms are more preferable due to an increase in the level of specificity. There are 5 isoforms of the enzyme with characteristic physicochemical properties.

Indications for the study

A doctor can write out a referral for a biochemical analysis of blood serum in order to determine the level of LDH if:

the patient has symptoms of chronic or acute damage to the integrity of cells and tissues;
a person feels severe pain in the chest area, which may be caused by myocardial infarction or angina pectoris;
it is necessary to control the course of chronic pathologies, including oncology;
large-scale screening of human health.

The norm of LDH in the blood

Any interpretation of the results should be carried out exclusively by a specialist. In view of the low specificity of the criterion under consideration, its isolated use for the final diagnosis of the disease is prohibited. Indicators of the normal concentration of LDH in adults and children in the blood are shown in the table.

It should be noted that LDH levels are normally higher in men than in women. Deviation from the reference (normal) values up or down indicates the development of the pathological process.

The value of indicators of LDH isoenzymes

The activity of isoenzymes is determined by the degree of inactivation by urea. It has been established that the level of inhibition of the enzymatic activity of human serum by urea ranges from 26 to 36%. This indicator is considered as a standard value for comparing the inhibitory properties of the five fractions of isoenzymes.

Isoenzyme	The level of inactivation from the total activity of urea, %
LDH-1	20-30
LDH-2	25-40
LDH-3	15-25
LDH-4	8-15
LDH-5	8-12

The table shows that each fraction has its own level of inhibition. Based on the known data on the priority organ for the synthesis of each isoenzyme, and the results of the analyzes, it is possible to determine with a high degree of probability the organ in which the disease develops.

Deciphering the results: reasons for the downgrade

It is noted that the level of LDH is lowered in the following cases:

the presence of oxalates (salts and esters of oxalic acid) and urea in the patient, which weaken the enzymatic activity of LDH;
taking medications that reduce the work of the enzyme (antibiotics, ascorbic acid);
the effectiveness of the chosen treatment tactics, leading to the normalization of the value of the criterion under consideration.

Causes of an increase in LDH in a biochemical blood test

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.

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.

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.

How to prepare

Preparation for the delivery of the analysis is necessary to obtain the most reliable and accurate results. The biological material is venous blood collected from the cubital vein at the elbow. Recommendations before analysis:

blood is given strictly on an empty stomach, for 1 day it is necessary to exclude fatty and fried foods from the diet;
it is strictly forbidden to drink juice, tea and coffee 12 hours before sampling the biomaterial, pure water without gas is allowed;
no smoking for 30 minutes;
Avoid alcohol and drugs for at least 48 hours. If it is impossible to cancel any drugs, notify the laboratory employee about their intake;
limit physical and emotional stress in 1 hour.

conclusions

Summing up, it must be emphasized:

LDH in a biochemical blood test is a low-specific criterion that suggests a number of diseases. To clarify the diagnosis, it is necessary to conduct additional laboratory and instrumental examinations;
when deciphering the results, it is important to take into account that the reference value for a child and an adult is different;
in the case of necrosis and infarction, which are characterized by cell destruction, it is recommended to repeat the analysis after the acute stage. This is necessary to assess the degree of tissue destruction and the severity of the pathology;
identification of the degree of activity of enzyme isoforms allows you to clarify the location of the pathology.

Material prepared
microbiologist Martynovich Yu. I.

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Glycolytic intracellular (cytoplasmic) enzyme lactate dehydrogenase (LDH, LDH), which accelerates the conversion of lactic acid into pyruvic acid, and also catalyzes the reverse reaction (reversible oxidation of L-lactate to pyruvate), is present without exception in all tissues of the human body. The highest content of LDH is observed in the heart, hepatic and renal parenchyma, skeletal muscles, red blood cells, where the enzyme is presented in the form of five isoenzymes (isoenzymes): LDH-1, LDH-2, LDH-3, LDH-4, LDH-5. The electrical mobility of these isoenzymes fully corresponds to that of globulins - α1, β1, γ1, γ2. The main concentration of LDH is concentrated inside the cells, serum is noticeably inferior in this regard.

In an adult who does not complain about his health, the total activity of lactate dehydrogenase in the blood serum normally ranges from 0.80 - 4.00 mmol/(h l) or 38 - 62 U/l (at 30°С).

Distribution of fractions in plasma. Age and norm

The first fraction (LDH-1 or HHHH tetramer) originates predominantly in the heart muscle and increases significantly in the blood serum with myocardial damage.

The second, third, fourth fractions (LDH-2, LDH-3, LDH-4) begin to actively enter the plasma under pathological conditions accompanied by a massive death of blood platelets - platelets, which occurs, for example, in the case of such a life-threatening condition as pulmonary embolism (PE).

The fifth isoenzyme (LDH-5 or MMMM tetramer) originates from the cells of the hepatic parenchyma and is released into the blood plasma in large quantities at the acute stage of viral hepatitis.

Due to the fact that different types of tissues accumulate and secrete different concentrations of LDH, the fractions of lactate dehydrogenase isoenzymes are distributed unevenly in the blood plasma:

LDH-1	17 - 27% (0.17 - 0.27 rel. units)
LDH-2	27 – 37% (0,27 – 0,37)
LDH-3	18 – 25% (0,18 – 0,25)
LDH-4	3 – 8% (0,03 – 0,08)
LDH-5	0 – 5% (0,00 – 0,05)

The activity of lactate dehydrogenase in red blood cells (erythrocytes) is 100 times higher than the levels of the enzyme contained in the blood plasma, and increased values are noted not only in pathological conditions, a number of physiological conditions, for example, pregnancy, the first months of life, or excessive physical effort on their part also contribute to an increase in LDH activity. Significant differences in the normal levels of this indicator are also due to age and gender, as evidenced by the table below:

Meanwhile, the norm indicators for blood LDH are always indicative, they should not be remembered once and for all, for the reason that the analysis can be performed at a temperature of 30 ° C or 37 ° C, the level is calculated in various units (µkat / l, mmol / ( h l), U/l or U/l). But since there is an urgent need to independently compare your own results with the norm options, it will be useful to first ask the institution that performed the analysis, the methods of its implementation and the units of measurement used by this laboratory.

Excretion of lactate dehydrogenase isoenzymes (LDH-4, LDH-5) by the kidneys does not exceed the level of 35 mg / day (excretion rate).

Reasons for the increase in LDH

The level of LDH activity is increased in almost any pathological process that is accompanied by inflammation and death of cellular structures, therefore, the reasons for the increase in this indicator are primarily considered:

The acute phase of myocardial infarction (a more detailed description of the changes in the LDH spectrum with necrotic myocardial damage will be presented below);
Functional insufficiency of the cardiac and vascular systems, as well as respiratory organs (lungs). Involvement of the lung tissue in the process and the development of circulatory failure in the pulmonary circulation (the level of LDH is increased due to the activity of LDH-3 and to some extent due to LDH-4 and LDH-5). The weakening of cardiac activity leads to circulatory disorders, symptoms of congestion and an increase in the activity of LDH-4 and LDH-5 fractions;
Damage to red blood cells (pernicious and hemolytic anemia), causing a state of tissue hypoxia;
Inflammatory processes affecting the lungs, as well as the renal or hepatic parenchyma;
Thromboembolism of the pulmonary artery, pulmonary infarction;
Acute period of viral hepatitis (in the chronic stage, LDH activity, as a rule, does not leave the normal range);
Malignant tumors (especially with metastasis), localized mainly in the liver tissue. Meanwhile, a strict correlation, in contrast to myocardial infarction (the larger the focus, the higher the LDH activity) between the progression of the oncological process and the change in the spectrum of lactate dehydrogenase is not observed;
Various hematological pathologies (polycythemia, acute leukemia, granulocytosis, chronic myeloid leukemia, anemia due to vitamin B12 deficiency or folic acid deficiency);
Massive destruction of platelets, which is often caused by blood transfusions that are not provided with sufficient selection for individual blood systems (for example, HLA);
Diseases of the musculoskeletal system, primarily damage to skeletal muscles (injuries, atrophic lesions, mainly at the initial stage of the disease).

LDH and cardiac muscle necrosis

The study of the glycolytic enzyme is very important diagnostic value in case of damage to the heart muscle, therefore refers to the main enzymatic tests that determine myocardial infarction on the first day the development of a dangerous necrotic process localized in the heart muscle (8 - 12 hours from the onset of the pain syndrome). The increase in enzyme activity occurs primarily due to the LDH-1 fraction and partly due to the second fraction (LDH-2).

After a day or two from a painful attack, the level of LDH in the blood reaches its maximum values and in most cases maintains a high degree of activity for up to 10 days. At the same time, it should be noted that activity is directly dependent on the area of myocardial damage(the larger the focus, the higher the value of the indicator). Thus, myocardial infarction, initially diagnosed using such laboratory tests as the determination of creatine kinase and the MB fraction of creatine kinase, can already be confirmed by this enzymatic study in a day (LDH is increased and increased significantly - 3-4 ... up to 10 times).

In addition to an increase in the total activity of lactate dehydrogenase and an increase in the activity of the LDH-1 fraction, the LDH / LDH-1 or HBDG (hydroxybutyrate dehydrogenase) ratio and the LDH-1 / LDH-2 ratio are of particular value for detecting acute myocardial infarction. Considering that the values of HBDG in the acute period of the disease change significantly upwards, and the total activity of lactate dehydrogenase will be reduced relative to rather high values of LDH-1, then the LDH/HBDH ratio will noticeably fall and will be below 1.30. At the same time, the LDH-1 / LDH-2 ratio, on the contrary, will tend to increase, trying to reach 1.00 (and sometimes even go beyond this limit).

Other reasons for changing odds

The above parameters, in addition to necrotic damage to the heart muscle, are subject to change in the case of other serious diseases:

Hemolytic anemia of various origins (LDH / HBDG decreases and becomes below 1.3);
Megaloblastic anemia (the content of the first fraction significantly exceeds the concentration of the second);
Conditions accompanied by increased cell destruction (acute necrotic process);
Neoplasms localized in the glands of the female and male reproductive organs: ovarian dysgerminoma, testicular seminoma, teratoma (only an increase in the concentration of LDH-1 is noted here);
Renal parenchymal lesions.

Thus, the main culprits, and, therefore, the main causes of changes in the concentration of the described indicators in the blood serum can be considered conditions associated with the destruction of cells of the hepatic and renal parenchyma, as well as blood cells (platelets, erythrocytes).

Separate nuances

For the study of LDH in the blood, 1 ml of serum is sufficient, which is extracted from the blood donated, as for any other biochemical test, in the morning on an empty stomach (however, if there is a question about the diagnosis of acute MI, then these rules, of course, are neglected).

In a laboratory study of LDH, hemolysis leads to a distortion of the analysis results (overestimates them). And when exposed to heparin and oxalate, the activity of the enzyme, on the contrary, in the serum will be reduced compared to the actual values of LDH in the blood. To prevent this from happening, work with the material should be started as early as possible, first of all, separating the clot with shaped elements from the serum.

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Often, after taking a biochemical blood test, the doctor indicates that lactate dehydrogenase (LDH) is elevated. This is an important enzyme, without which the process of glucose oxidation and the formation of lactic acid can be disrupted. In the body of an adult, this substance does not accumulate, but is immediately excreted. If an increase in LDH is noticed, then this may indicate various diseases.

Indicator norms

The main component of the circulatory system and tissues is LDH. It is formed during breathing. The enzyme is involved in the breakdown of glucose, converting it into lactic acid. As a result, oxygen enters the body. If this process is disturbed, then only glucose is consumed, an increase in lactate occurs.

In a healthy person, lactate dehydrogenase does not accumulate, but is immediately excreted by the genitourinary system. If pathological processes are observed in the body, then an increase in LDH in the blood is noted.

This enzyme is present in almost all organs, but the largest amount is observed in the liver, skeletal muscles and myocardium. Therefore, five isoenzymes are distinguished, which differ from each other in structure and specificity, since they are located in different parts of the human skeleton.

There are five areas:

LDH-1 is located in the brain and heart muscle tissues.
LDH-1 and LDH-2 can be found in the kidneys and blood cells.
LHD-3 - in skeletal muscle, pancreas, lungs, thyroid gland, adrenal glands and spleen.
LGD-4 is found in the liver, placenta, in males in the germ cells, as well as in LGD-3.
LDH-5 - in the liver, skeletal muscles and other organs.

Each type of lactate dehydrogenase has its own location, which helps to quickly find out the cause of the pathology and prescribe the appropriate treatment. In addition, the indicators of this enzyme in men and women differ, which proves that the strong half of humanity is more often engaged in power loads.

In medicine, there are special values by which the level of this substance is checked. Deviations up or down indicate some kind of disease. The norm of the indicator depends on age and gender, since at birth it is overestimated, and during the period of growing up, the value decreases markedly.

LDH parameters for children and adults:

In newborns, a value below 2000 units / liter of blood is considered normal.
In children under 2 years old - 430 U / l.
From 2 to 12 years old - 295 units.l.

In women, the value can range from 135 to 214 units.l.
For men - 135-225 units.l.

In some cases, the parameters may differ significantly, and this will not indicate a disease. However, additional tests are needed to find out the cause of the decrease/increase in the level during the study.

Purpose of Enzyme Research

It is often prescribed to take a biochemical blood test to determine lactate dehydrogenase. According to its content, human diseases are diagnosed, because with damage to the internal organs and their systems, a rapid increase in LDH is observed. This is especially important for checking the tissues of the heart, brain, liver. In case of violation of their work, the accumulation of this substance in the body is observed.

Usually indications for a blood test for this enzyme are:

diagnosing cardiovascular diseases, chest pain;
suspicion of cancerous tumors;
muscle pathological processes;
cancer control;
anemic condition;

comprehensive examination.

Recently, this method is losing its relevance, as there are more extensive studies to establish the cause of the disease. But they differ in the technical side and the high cost of analysis, in addition, they need to be taken in paid laboratories.

How should you prepare for donating blood? Three days before the procedure, it is not recommended to take medications and refrain from alcohol. Blood should be taken on an empty stomach, food is not recommended to be consumed eight hours before the procedure, doctors advise quitting smoking half an hour before the procedure and avoid physical activity.

How is the procedure carried out? Blood is taken from a human vein. Then whey is obtained from it and it is checked how much lactate is present. The results are ready on the second day.

The analysis for the determination of LDH is simple, since it requires taking a small amount of blood from a vein. It is important that the serum is fresh in order for the result to be correct.

Based on the data obtained, if necessary, the doctor conducts an auxiliary examination and makes a diagnosis. Thus, thanks to this enzyme, pathological processes can be detected at an early stage before the onset of primary symptoms.

The indicator deviates from the norm

An increase in lactate dehydrogenase appears with the destruction of cellular structures and tissues. This condition causes various diseases, so it is not difficult to diagnose.

If the LDH level is elevated, then the following pathologies may be the causes:

cardiovascular disease, including heart attack or stroke;
pulmonary insufficiency;
cirrhosis of the liver;
hepatitis, jaundice;
blood diseases (leukemia, anemia);
pancreatitis in the acute phase;
damage to the skeleton or muscle tissue during injuries;
hypoxia;
breathing problems, lack of oxygen;
AIDS, HIV.

It is worth noting that if LDH is elevated during pregnancy, then this is considered normal, but in some cases this parameter may indicate placental abruption. Therefore, the doctor may prescribe an additional examination of the patient in order to exclude pathological processes.

Sometimes the value can be influenced by some factors that were formed at the time of blood donation, and this will not indicate the presence of diseases.

These include:

skin diseases (allergies, cuts);
drinking alcoholic beverages the day before blood donation;
physical or psychological stress;
taking any medications (aspirin, insulin);
thrombocytosis.

Therefore, it is important to find out why lactate dehydrogenase is elevated (reasons), while eliminating all possible false assumptions. Only in this case, the doctor will be able to identify the reasons for the increase in the enzyme.

By itself, an elevated LHD in the blood cannot indicate a disease, so an additional examination is required. To do this, the specialist determines the value of one or more isoenzymes. Only in this case it is possible to establish the cause of the disease.

For example, a high level of LDH isoenzymes 4 and 5 was found in a person. In this case, damage to the liver or muscle tissue occurs. The doctor examines this organ, takes additional tests and finds out abnormal processes.

In myocardial infarction, a high value of the element is seen on days 3-5 and remains in this state for about ten days. With blood leukemia, the initiative of LDH-2 and LDH-3 is noted. Cancer tumors are characterized by an increase in LDH-3,4,5.

It should be noted that the amount of LDH in the blood of cancer patients can decrease with effective treatment, so this analysis is used to monitor the patient's condition.

Decreased LHD is less common and is not a pathology. Sometimes some factors can affect this, therefore, by eliminating them, you can increase this parameter. Usually this phenomenon is affected by the intake of vitamin C and other medications.

Treatment Methods

In order for the level of lactate dehydrogenase to return to normal, it is necessary to find out the reason for its increase, taking into account all additional examinations. Only in this case, the therapy of this disease will give a positive result.

With myocardial infarction, drugs are prescribed to improve blood circulation and maintain the functionality of the heart. Blood is often taken from the patient and LDH levels are checked. With successful treatment, this figure, as a rule, decreases.

With anemia, it is recommended to follow a diet that includes iron-containing foods, take medications that increase hemoglobin levels. Cancer therapy involves the use of radiation or chemotherapy. In some cases, surgery is needed to remove cancerous tumors. Treatment of the acute form of pancreatitis is carried out in a hospital under the supervision of a doctor. Painkillers, gastric lavage, droppers are usually prescribed. In severe cases, removal of the pancreas is required.

Thus, an increase in LDH parameters occurs in the presence of an inflammatory process in the body or other formations.

High rates may indicate the development of serious diseases and anomalies. Therefore, it is important to consult a doctor so that he can prescribe an additional study and identify the causes.

Timely treatment will help normalize the enzyme in the blood and avoid serious complications in children and adults.