LDH (Lactate Dehydrogenase) High and Low Levels, Normal Values, and Meaning

LDH (Lactate Dehydrogenase)

Lactate dehydrogenase or lactic acid dehydrogenase is a type of enzyme that functions during cellular respiration at the cellular level. Cellular respiration is a metabolic process that involves breaking down glucose obtained from nutrients to produce energy. Enzymes are proteins that act by accelerating chemical reactions and metabolism. Most tissues in the body contain and use the lactic acid dehydrogenase enzyme. Most commonly seen in red blood cells, kidneys, liver, and muscles, this enzyme can be an indicator of cellular damage. In tissues, old cells need to be destroyed and replaced with new ones. These destroyed cells can release a certain amount of lactate dehydrogenase into the bloodstream, and this process is normal. The release of more LDH than normal may indicate intensive cell destruction and tissue damage. Although it is not always a standalone marker, attention should be paid to it during health check-ups.

What is LDH (Lactate Dehydrogenase)?

Lactate dehydrogenase (LDH) is an enzyme that aids anaerobic metabolic activities. It functions in an oxygen-free environment during the cellular respiration and ATP production cycle. In glucose metabolism, when oxygen is limited or absent, it ensures the conversion of pyruvate to lactate. Lactate affects the immune system, warning the body through signals in times of danger. In addition to being a signaling molecule, lactate can also play a role as an energy source and a pH regulator. LDH is found in many organisms, including plants, animals, and humans. The lactate dehydrogenase enzyme is present in almost every tissue in humans. However, approximately 40% of total lactate production occurs in skeletal muscles. Apart from this, it can show high concentrations in the liver, kidneys, and red blood cells. Since it is present in most tissues and organs, it can provide information about tissue turnover. It is generally an indicator that can point to tissue damage. It may also signal the presence of certain health problems. Therefore, in some cases, its values may be higher or lower than normal. In general, it can be considered a non-specific marker.

What is the LDH (Lactate Dehydrogenase) Test?

The LDH test is used to diagnose tissue damage occurring in the body. The lactate dehydrogenase test is performed using samples taken from blood or other body fluids. Body fluids can be collected from the spinal cord, abdomen, chest, or lungs. Under normal conditions, having a certain amount of LDH in the blood and body fluids is considered normal. When cells located in specific tissues are damaged, LDH leaks out of the cells. When this leakage is excessive, acute or chronic damage needs to be detected. Although it indicates the general state of damage, this test cannot determine which tissue is undergoing destruction. The reference range for LDH in adults is considered to be approximately 140-280 U/L. This value is 135-750 U/L in newborns, 180-435 U/L in children up to 12 months, and 122-222 U/L in children over 18 years old. The reference range may vary depending on the person's symptoms, physiological state, and laboratory conditions. It is normal for newborns and infants to have higher LDH levels compared to older age groups. Additionally, certain physiological and environmental conditions can alter blood LDH values. Intense exercise, high vitamin C concentration, medications, infectious diseases, injuries, and traumas can be counted among these conditions.

For the Detection of Which Diseases is the LDH (Lactate Dehydrogenase) Test Performed?

Lactate dehydrogenase, found in most body cells and tissues, can be measured as it leaks from tissues in the event of damage. Therefore, an increase in blood LDH can be observed, and values can be checked with the test. LDH levels may be necessary for detecting many different diseases. These diseases mainly include:

Anemia,

Heart attack,

Liver diseases,

Bone fractures,

Muscle traumas,

Encephalitis,

Meningitis,

HIV/AIDS,

Cancers,

COVID-19,

Hepatitis,

Pulmonary embolism,

Acute renal failure.

Depending on the severity and type of tissue damage, lactate dehydrogenase can remain high in the blood for up to 7 days. Dead cells lose their cytoplasm, disperse into the serum, and remain in circulation for a while. Since it is not clinically sufficient for diagnosis, additional analyses such as ALT, troponin, and CK may be needed. An increase in LDH values can be seen in many types of cancer. Therefore, it may not be a specific marker for determining the type of cancer. Generally, values 40 U/L higher than normal levels can be seen in leukemia, metastatic carcinoma, and CNS lymphoma. Extremely high lactate dehydrogenase may be associated with serious illnesses such as multiple organ failure.

What is High LDH (Lactate Dehydrogenase)?

Serum LDH elevation can be an indicator of a possible infection, injury, or disease in the body. Typically, values of 222 U/L and higher are explained as high LDH. Strenuous activities and exercise can lead to elevated lactate dehydrogenase in the blood. During intense exercise, an adequate amount of oxygen may not reach the muscles, and anaerobic metabolism becomes activated. Additionally, some health problems such as the following may be causes of high LDH:

Pancreatitis,

Cirrhosis,

Kidney disease,

Lung disease,

Leukemia,

Lymphoma,

Malaria,

In addition, medications such as aspirin, narcotics, anesthetics, procainamide, and alcohol use can also cause high values. During the treatment process of a disease, a decrease in LDH levels may indicate that the body is responding well to treatment. It may point to a better prognosis in cases such as liver damage and myocardial infarction.

What is Low LDH (Lactate Dehydrogenase)?

Low blood LDH or deficiency is a very rare health condition. Low LDH can mainly result from mutations occurring in the LDH-A and LDH-B genes. As a result of these mutations, deficiencies can occur in LDH-A and LDH-B proteins. The LDH-A gene mutation can primarily affect skeletal muscles. Furthermore, this gene deficiency can also reduce the amount of enzyme in other tissues and lead to the ineffective breakdown of glycogen. Therefore, it is called "Glycogen storage disease type XI." This disease can lead to muscle weakness and the breakdown of muscle tissues. It may show distinct effects, especially during intense activities. As a result of destruction in the muscle tissue, myoglobin is released, excreted in the urine, and causes myoglobinuria. The accumulation of high amounts of myoglobin can invite kidney damage and renal failure. The LDH-B gene mutation has the characteristic of affecting the heart muscle. No symptoms may be observed in this clinical picture. LDH-A and LDH-B mutations can promote tumor formation. In severe cases, consult your doctor for the treatment of low LDH.

Frequently Asked Questions

While high LDH on a blood test may sometimes be due to environmental conditions, it can occasionally point to a serious health problem. Underlying diseases can lead to significant LDH elevation. In this case, it is strongly recommended to seek medical help. An LDH test result higher than the normal reference range should be checked at regular intervals, and its source should be determined. The normal LDH value is determined as 135-750 U/L in newborns, 180-435 U/L in infants, 122-222 U/L in young adults over 18, and 140-280 U/L in adults. In some cases, factors such as medication use, exercise, etc., can be effective in changing levels even if there is no health problem. Lactate dehydrogenase is at higher levels in infants and children compared to adults. While 135-750 U/L is accepted as the normal reference range in newborn babies, a reference range of 180-435 U/L is taken as the basis for older children. When excessive LDH reaches serious dimensions, organ damage and treatment failures may manifest themselves. According to data, having an LDH value >1000 U/L can carry dangerous consequences in the diagnostic and treatment process. Therefore, when it rises above the normally accepted range, it is important to access early diagnosis and treatment. Rare low LDH typically stems from gene mutations. Lactate dehydrogenase A deficiency, namely glycogen storage disease type XI, and lactate dehydrogenase B deficiency can cause low LDH levels. However, in some tests, low LDH values may be associated with the consumption of high concentrations of vitamin C. Serum LDH elevation can be seen in tumor or cancer cases such as metastatic melanoma, leukemia, lymphoma, multiple myeloma, testicular cancer, metastatic carcinoma, and ovarian germ cell tumors. It may not be a specific indicator on its own, but careful monitoring may be recommended. The LDH enzyme is frequently confused with LDL cholesterol. LDH is not a type of cholesterol, but a protein. Therefore, "high LDH cholesterol" cannot be defined. LDH is an enzyme involved in anaerobic respiration and energy production pathways in body cells. LDL cholesterol is a type of lipoprotein in the blood. It is responsible for transporting fats in the bloodstream and to various cells. It contains a high amount of cholesterol and a small amount of protein. High LDL cholesterol in the body carries the risk of plaque formation in the arteries, heart attack, and stroke. High LDH in infants and children is caused by a high amount of the lactate dehydrogenase enzyme released into the bloodstream. While this picture does not yield a specific result in some cases, it points to a serious health problem in others. High LDH in babies can stem from serious health issues such as infections like COVID, types of cancer, injuries, and trauma. Injury, trauma, infection, intense physical activity, various types of cancer, liver, lung, and kidney diseases, anemia, heart attack, and the use of aspirin, anesthetic, and narcotic drugs can be among the symptoms of high lactate dehydrogenase. The severity of lactate dehydrogenase elevation can vary depending on the stage and severity of the disease. The lactate dehydrogenase enzyme, which is found in high concentrations in the liver, can rise due to various problems. High blood LDH can be a harbinger of an infection, damage, or disease in the liver, but it may not provide a definitive diagnosis on its own. Other liver markers such as ALT, AST, and GGT may need to be evaluated alongside the lactate dehydrogenase enzyme.

High or low LDH values may point to many different health conditions. You can make an appointment with our specialist physicians for a definitive diagnosis and proper treatment. Hisar Hospital Online Appointment