Definition method Lactate => Piruvat (IFCC).
The material under study Serum blood
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Synonyms : Lactate dehydrogenase; L-lactat; Over + oxidoreductase; Dehydrogenase of lactic acid.
Lactate Dehydrogenase, Total; Lactic dehydrogenase; LDH; LD.
Brief description of the determined analyte LDH (lactate dehydrogenase)
The glycolic enzyme involved in the final stages of the transformation of glucose (catalysis of mutual and lactate mutual and lactate).
The zinc-containing enzyme is localized mainly in the cytoplasm and detecting in almost all organs and tissues of man. The greatest activity is celebrated in the kidneys, liver, heart, skeletal muscles, pancreas, blood cells. In the erythrocytes, its level is 100 times higher than in serum. In children, the activity of the enzyme is higher than in adults, with age, the activity of LDG serum smoothly decreases.
For what purpose determine the level of LDH in serum
Evaluation of the level of LDH in serum helps to identify states accompanied by damage to cells and tissues.
What can affect the activity of the enzyme LDH
LDH activity indicators depend on the study method. Increased activity of LDH in physiological conditions is observed in pregnant women, newborns, after intense physical exertion. Enzyme activity in women is somewhat lower than in men.
Monitoring the flow of myocardial infarction. The growth of LDH activity is observed by 12-24 hours after a heart attack; Maximum activity is marked after 24-48 hours. Increased enzyme activity keeps up to 10 days. The activity of LDH depends on the size of the focus of the myocardial damage, and the dynamics of its decline in the process of recovery - from the intensity of reducing processes in the heart muscle. The definition of LDH activity allows you to differentiate a true myocardial infarction and clinically similar attacks of angina: with a heart attack, the total activity of LDH increases and as a result of its value several times higher than the normal level, at the same time, even with severe angina rises, the level of activity LDH corresponds to the norm. A decrease in the activity of the enzyme in the post-infarction period occurs 2 times more slowly than the normalization of such markers of myocardial lesions, as creatine equiation and AST, which is especially valuable for the late diagnosis of defeat.
Lacattehydrogenase is one of the enzymes. Defined in laboratory diagnostics, characterized by low specificity. But if LDH in blood is increased or has been understood, it allows you to identify various diseases in the early stages and failures in the functioning of important systems of the body.
Causes of deviation from the norm
Increased and decrease in LDG can be determined as a result of various diseases:
- pathology of the lungs or blockage of their vessels thrombus;
- malignant neoplasms;
- Atrophy or injuries of bones and muscle tissues;
- Myocardial infarction with the ignition of the middle layer of the heart fabric;
- Pathological change in blood composition with severe destruction of red blood cells;
- violation of the functioning of the kidneys and liver;
- Infectious mononucleosis
- Pathology of the thyroid gland.
The deviation of LDG in cells from normal parameters in pregnant women, in addition to the listed causes, may be due to premature discontinuation of the placenta.
The norm of LDH in the blood in women, children and men changes in accordance with the age of man. Deciphering lactate dehydrogenase indicators for children is determined by the table:
|Age||Indicators, norm (U / l )|
|up to 1 year||up to 450.|
|2-3 years||up to 345.|
|4-6 years old||up to 315.|
|7-12.||up to 300.|
|13-18||up to 270.|
In people, over 18 years old, normal indicators are determined in accordance with the floor. So, for the female body, this parameter can vary from 13 to 220 units / l. In men, with the norm, the value of LDG is higher than in women and make up 130 - 235 units / l.
A significant reduction or an increase in units indicates the development of pathologies. But it should be borne in mind that the non-compliance with reference indicators may arise due to improper preparation for biochemical analysis: excessive physical activity, receiving certain drugs.
What if LDH is not normal?
In order to normalize the level of the enzyme, you must first find out why deviations arose. Only by setting the reasons for the reduced LDH in the blood and eliminating the underlying disease, which is a catalyst, will be able to return the values to the normal range. To determine the reason, it is necessary to undergo a detailed examination, since each pathology has its own nuances of treatment. Under anemia, power correction is carried out and preparations are prescribed to restore iron balance, during cancer diseases, a large-scale patient screening is prescribed, in the case of acute forms of pathologies, inpatient treatment is determined.
Accurate definition of LDH in short time
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Lactate dehydrogenase (LDH) in the blood is a laboratory criterion 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 the destruction of muscle tissue in humans.
What is it ldg in the blood?
In order to understand for what purpose the analysis is prescribed initially, it should be understood - what is LDH in biochemical analysis of blood?
Lacatadehydrogenase (LDH) in the blood is an enzyme localizing inside cells. The composition necessarily includes zinc ions. The main function is to catalyze the process of oxidation of lactic acid to pyruvate. Almost all cells in the human body contain the enzyme LDH. The maximum concentration is noted in skeletal (9000 URS / D) and cardiac (25,000 units / d) muscles, as well as in kidneys (15,000 units / d), lungs (9500 U / d) and liver (9000 U / d).
In case of damage to the cell, the enzyme release into the bloodstream is active. Blood cells also contain LDH, however, their content is slightly. That is why even with a slight destruction of tissues of any of the organs there is a sharp increase in the level of LDH in the serum, which is used to diagnose various diseases. This fact allows us to attribute blood test for LDH to highly sensitive, but low-specialized criteria.
From the point of view of the informative of the results of the IOFORM, LDH are more preferred by increasing the level of specificity. Famous 5 enzyme isoforms with characteristic physicochemical properties.
Organ in which is produced
|LDH-1.||HHHH, H. 4||Heart, Kidney, Red Blood Blood Blood|
|LDH-2||HHHM, H. 3M||Selezenka, lymph nodes|
|LDH-3.||HHMM, H. 2M2||Lungs|
|LDH-4.||Hmmm, Hm. 3||Placenta, pancreas|
|LDH-5.||MMMM, M. 4||Skeletal muscles, liver|
Correct the direction on the biochemical analysis of blood serum in order to determine the level of LDH doctor may if:
- The patient has symptoms of chronic or acute damage to the integrity of cells and tissues;
- A person feels a strong pain in the chest area, the cause of which can be a myocardial infarction or angina disease;
- It is necessary to control the flow of chronic pathologies, including oncology;
- A large-scale human health screening is carried out.
Any decoding 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.
Normal values, ed / l
|Both||0-1 year||Up to 451.|
|1-3 years||Up to 344.|
|3-6 years old||Up to 314.|
|6-12 years old||Up to 332.|
|12-18 years old||Until 271.|
|Women||From 18 and older||130 - 215|
|Men||130 - 230.|
It should be noted that, normal, the level of LDH in men is higher than in women. Deviation from reference (normal) values to a large or smaller direction indicates the development of the pathological process.
The value of the parameters of LDH isoenzyme
The activity of isoenzymes is determined by the degree of inactivation of urea. It has been established that the level of inhibition of the enzymatic activity of human urea serum is ranging from 26 to 36%. This indicator is considered as standard to compare the inhibitory properties of the five fractions of the isoenzymes.
Inactivation level from the general activity of urea,%
It can be seen from the table that for each fraction corresponds to its inhibition level. Based on the known data on the priority synthesis of each isoenzyme, and the results obtained are obtained with a high proportion of the likelihood of determining the body in which the disease develops.
Decoding results: reasons for lowering
It is noted that the level of LDH is reduced in the following cases:
- the presence of oxalate patients (salts and esters of oxalic acid) and urea, which weaken the enzymatic activity of LDH;
- reception of drugs that reduce the work of the enzyme (antibiotics, ascorbic acid);
- The effectiveness of the selected treatment tactics, leading to the normalization of the value of the criterion under consideration.
Causes of increasing LDH in biochemical blood test
The criterion under consideration may deviate from normal values in a number of different diseases. The reasons for increasing the concentration of lactate dehydrogenesis may be:
- Myocardial infarction, accompanied by ischemic necrosis of the middle layer of muscular heart fabric;
- clogging of the artery of a lung thrombus or infarction of lungs;
- blood pathology for which the destruction of red blood cells is characterized (various types of anemia, hemolysis, severe intoxication);
- malignant tumors affecting various organs and fabrics often accompanied by metastasis;
- violations in the work of the liver against the background of chronic and acute hepatitis, ultrasound diseases or alcohol intoxication;
- kidney pathology (glomerular nephritis, pyelonephritis);
- Atrophy or muscle tissue injury;
- open and closed fractures;
- stagnant cardiac or coronary failure;
- inflammation of the heart muscle tissue;
- mononucleosis, viral etiology;
- acute attack of pancreatitis;
- convulsive seizures;
- alcoholic delirium (mental deviations on the background of a sharp abolition of alcohol);
- burn disease;
- detachment of the placenta ahead of time;
- Hyperfunction of the thyroid gland.
When identifying the reasons for increasing LDH in women and men, it is necessary to eliminate the influence of factors that can lead to unreliable results:
- Wrong blood pressure, as a result of which red blood cells (hemolysis) collapsed in the tube;
- Neglecting the rules of preparation for the delivery of biomaterial: physical and emotional stresses, smoking, alcohol, improper diet;
- The use of treatment methods accompanied by the patient's electrostimulation a week before the analysis;
- overweight blood platelets;
- Acceptance of drugs that activate the operation of the enzymatic system.
Normalization of the level of LDH in the blood
Patients are often wondering - how to reduce the level of the enzyme? To do this, it is necessary to initially establish the exact reason for the increase in LDH. Only in the elimination of the disease, which was the cause, it is possible to return the indicator to normal values. Each pathology therapy has its own characteristics:
- After the first signs of myocardial infarction, it is necessary to provide first aid. Any delay in treatment can lead to a fatal outcome and development of 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 be returned to the norm;
- With anemia provoked by the lack of iron, the patient's nutrition is corrected, and iron-containing drugs are prescribed. A favorable outcome is considered to increase the level of hemoglobin and the decline - LDH;
- When oncopathology, a large-scale patient screening is needed to assess the size of the tumor, the presence of metastases and the degree of damage to organs. At the same time, the evaluation of the effectiveness of treatment includes analysis on LDH and the main oncomarkers. The lack of positive dynamics expressed in reducing the criteria under consideration is a reason for the translating of the patient to more aggressive treatment methods;
- In the case of acute pancreatitis, it is necessary to premire the patient in a 24-hour hospital. Treatment includes droppers with painkillers, antibacterial and anti-inflammatory drugs. As the patient's condition improves, all biochemical indicators come to normal.
How is LDH analysis?
To estimate the level of LDH and its enzymatic activity, 2 groups of techniques are used:
- spectrophotometric, the essence of which is to determine the differences in the absorption spectra of the oxidized form over (coenzyme of all living cells) from the restored;
- Colorimetric, divided into dinitrophenylhydrazine - determination of the concentration of pyruvate, and redox endicatorial - detecting certain molecules using indicators that change the color.
An optical test is used as standards to determine the enzymatic activity of LDH, and for the isoenzymes - electrophoresis. When issuing results of analysis, the laboratory must indicate the selected technique.
How to prepare for research
Preparation for the surrender is necessary to obtain the most reliable and accurate results. The biological material is venous blood collected from the cubital vein on the elbow bending. Recommendations before analysis:
- Blood surrendered strictly on an empty stomach, for 1 day it is necessary to exclude fatty and fried dishes from the diet;
- It is strictly prohibited 12 hours before the intake of biomaterial drink juice, tea and coffee, clean water without gas is allowed;
- in 30 minutes do not smoke;
- At least 48 hours do not drink alcohol and drugs. If it is impossible to cancel any drugs to warn about their reception of the laboratory employee;
- limit physical and emotional stress in 1 hour.
Summing up, you need to emphasize:
- LDH in biochemical analysis of blood is a low-specialized criterion that allows us to assume a number of diseases. To clarify the diagnosis, additional laboratory and instrumental examinations are required;
- When deciphering the results it is important to take into account that the reference value of the child and adult is different;
- In the case of necrosis and infarction for which cell destruction is characterized by re-conducting analysis after an acute stage. This is necessary to assess the degree of destruction of tissues and the severity of pathology;
- Detection of degree activity of enzyme isoform allows you to clarify the location of pathology.
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