Lactate dehydrogenase (LDH)

Lactate dehydrogenase (LDH) Is an intracellular enzyme that is important for the production of energy in almost every cell in the body.

The highest concentrations of LDH are found in the heart, liver, muscles, kidneys, and lungs.

The test determines the concentration of LDH in the blood and in some body fluids. Only small amounts of LDH may be detected in the blood because the enzyme is secreted into the bloodstream during cell damage and death. Thus, serum lactate dehydrogenase is a nonspecific marker of tissue damage in the body.

Although the increase in LDH is nonspecific, this test is useful for confirming the diagnostics of myocardial infarction or pulmonary infarction. During myocardial infarction, elevated levels of LDH persist longer than those of other enzymes.

Determining LDH alone can not help us determine the exact cause of the injury, so its test is always combined with other tests.

When should we take a test for lactate dehydrogenase?

Determination of blood lactate dehydrogenase:

• Detecting tissue damage in the body;
• Diagnosis and follow-up of hemolytic or megaloblastic anemias;
• Monitoring and prognosis of some cancers, such as lymphoma, leukemia, melanoma, and germ cell tumors.

Determination of tissue lactate dehydrogenase:

• Determination of LDH in cerebrospinal fluid - to distinguish between bacterial and viral meningitis;
• Determination of LDH in pleural, pericardial, and peritoneal fluids to differentiate exudate from transudate. Exudate occurs during inflammation or tissue damage, while transudate formation is caused by intravascular pressure and an increase in protein in the blood.

How to prepare for the test?

The test should be performed on an empty stomach.

Research material

Venous blood

Possible interpretation of the results

LDH concentration increases:

• In myocardial infarction, the level of LDH increases 36-55 hours after the onset of the process and its elevated level is maintained for 3-10 days;
• An increase in LDH during pulmonary infarction is observed within 24 hours of the onset of chest pain.

Other conditions associated with elevated LDH levels:

• Congestive heart failure;
• Liver disease (cirrhosis, alcoholism, acute viral hepatitis);
• Tumors - leukemia, lymphoma;
• Hypothyroidism;
• Muscle disorders (dystrophies, trauma);
• Megaloblastic and hemolytic anemias;
• Shock;
• Hypoxia;
• Hypotension;
• Hyperthermia;
• Renal infarction;
• Acute pancreatitis;
• Fractures;
• Intestinal obstruction;
• Infectious mononucleosis.

LDH concentration decreases:

Adequate response to cytostatic therapy.

Resources

https://www.synevo.bg/ldh/
https://www.synevo.ro/shop/lactat-dehidrogenaza-ldh/