Publish what kind of analysis ldg. Deciphering LDH in a blood test

Lactate dehydrogenase (or LDH) in the blood is determined to detect a whole range of various diseases, in particular oncological, cardiac or liver pathologies. LDH is an enzyme that takes part in the formation of lactic acid in the body through the oxidation of glucose. What is LDH in a biochemical blood test, and what pathological conditions may indicate a deviation of the indicator.

The norm of LDH in the blood

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

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

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

Lactate dehydrogenase is elevated

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

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

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

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

Since each organ has the so-called LDH isoenzymes (LDG1,2,3,4,5). With an increase in LDH 1 and 2, we are most likely talking about myocardial infarction, and a high concentration of the enzyme in the blood lasts for 10 days after a heart attack. With the growth of LGD 1 and 3, one can suspect the development of myopathy in a person. If LDH 4 and 5 enzymes are especially active, then it is possible to judge liver disorders, for example, in acute hepatitis. Also, these isoenzymes can be increased in case of damage to muscles and bones, with possible damage to internal organs. If you suspect the development of cancer, especially pay attention to the concentration of LDH 3, 4 and 5.

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

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

What is the definition of LGD used for?

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

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

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

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

Basic concepts and functions of LDH

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

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

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

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

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

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

Indications for research

Blood biochemistry is prescribed:

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

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

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

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

Blood test

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

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

Venous blood sampling is performed in the morning in the laboratory

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

Standard values

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

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

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

Reasons for deviations

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

Increased rate

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

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

Myocardial infarction is accompanied by an increase in LDH

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

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

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

Reduced rate

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

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

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

Non-pathological change in indicators

Factors that skew the results include:

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

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

Additionally

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

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

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

Results

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

Normative values of blood levels in adults

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

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

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 glucose oxidation - 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 pain in the chest (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.

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 the metabolism of the cell 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 pain 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.

Description

Method of determination Lactate => pyruvate (IFCC).

Material under study Serum

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Glycolytic enzyme involved in the final stages of glucose conversion (catalysis of the interconversion of pyruvate and lactate).

Zinc-containing enzyme, localized mainly in the cytoplasm and found in almost all human organs and tissues. The greatest activity is observed in the kidneys, liver, heart, skeletal muscles, pancreas, blood cells. In erythrocytes, its level is 100 times higher than in serum. In children, the enzyme activity is higher than in adults; with age, serum LDH activity gradually decreases.

Indicators of LDH activity depend on the research method. Increased LDH activity under physiological conditions is observed in pregnant women, newborns, after intense physical exertion. Enzyme activity in women is slightly lower than in men.

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 angina pectoris attacks that are clinically similar to it: during 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 corresponds to the norm. 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.

Training

It is preferable to take blood in the morning on an empty stomach, after 8-14 hours of a night fasting period (you can drink water), it is permissible in the afternoon 4 hours after a light meal. On the eve of the study, it is necessary to exclude increased psycho-emotional and physical activity (sports training), alcohol intake.

Indications for appointment

Diseases of the hepatobiliary system.

Myocardial infarction (early diagnosis, differential diagnosis and monitoring).

Anemia with hemolysis.

Interpretation of results

The interpretation of test results contains information for the attending physician and is not a diagnosis. The information in this section should not be used for self-diagnosis or self-treatment. An accurate diagnosis is made by the doctor, using both the results of this examination and the necessary information from other sources: history, results of other examinations, etc.

Units of measurement in the Independent laboratory INVITRO: U / l.