What is LDH (Lactate Dehydrogenase)? LDH High and Low

LDH (Lactate Dehydrogenase), an enzyme found in body cells and required for energy production, plays a role in converting glucose in cells into energy. In this process, it ensures the transformation of substances such as lactate and pyruvate. LDH enzyme is in many tissues and organs; It is especially concentrated in the heart, liver, muscles, kidneys and blood cells. Levels of this enzyme in the body can be an important marker in diagnosing various health conditions. Measuring LDH levels plays a critical role in detecting damage or disease in the body. Therefore, the LDH test is an important blood test frequently requested by doctors and used in assessing health status.

What is Lactate Dehydrogenase (LDH)?

Enzymes are proteins that help speed up metabolism or chemical reactions in the body. They form some substances and break down others. Lactate dehydrogenase (LDH) is an important enzyme that helps cellular respiration. It is found in almost every cell of the body, including blood, muscles, brain, kidneys and pancreas.

What is LDH used for?

LDH is present in almost all tissues in the body. Its highest concentrations are in muscle, liver, kidneys and red blood cells. There are five forms of the LDH enzyme called LDH isoenzymes. Each isoenzyme has a slightly different structure:

• LDH-1: It is found in the heart and red blood cells.
• LDH-2: It is present in white blood cells. It is also found in lower amounts than LDH-1 in the heart and red blood cells.
• LDH-3: Found in the lungs. It is present in smaller amounts in other tissues.
• LDH-4: It is found in the kidney and pancreas. If you are pregnant, LDH-4 is also seen in the placenta (the organ that brings oxygen and nutrients to the baby).
• LDH-5: Found in the liver and muscles that connect to your bones to help with movement.

As new cells form in tissues, the body gets rid of old or “dead” cells. This normal process causes tissues to release LDH into the bloodstream or other body fluids. Therefore, it is normal to always have some LDH in a blood or fluid sample. However, if disease or injury damages the tissues that contain LDH, the cells release LDH isoenzymes into your bloodstream. As a result, your LDH levels rise above normal.

How to Test for LDH?

It is done by taking a blood sample from a vein in the arm with a small needle. If your doctor thinks you have a condition that may affect LDH levels in body fluids, you may undergo a procedure to obtain a fluid sample. In some cases, samples of brain and spinal cord, chest and abdominal fluids may be taken.

Why is LDH Test Requested?

The LDH test measures the amount of LDH in blood or other body fluids. It is mainly used to control tissue damage. Many acute (sudden) and chronic (long-term) conditions can damage tissues. As a result, high LDH levels may occur. Therefore, LDH testing can be used in many different situations, from bone and muscle injuries to monitoring cancer treatment. LDH test Some of the reasons why this is desired can be listed as follows:

• It may be ordered to help diagnose or monitor diseases such as anemia, liver, lung, kidney, heart, pancreas, brain and spinal cord problems, encephalitis and bacterial meningitis.
• It may be done to monitor conditions that may worsen over time, such as muscular dystrophy and HIV.
• It is necessary to help diagnose some serious infections.
• It is ordered to check the course of certain types of cancer, including multiple myeloma, lymphoma, leukemia, testicular cancer, and melanoma.
• It helps to check whether treatment for certain types of cancer is working.

What are LDH Normal Values?

Values ​​vary depending on age. Babies and young children will have much higher normal LDH levels than adults or older children. LDH is usually reported as units per liter (U/L). In general, normal blood LDH value is as follows:

What Does High LDH Mean?

High LDH levels indicate some type of tissue damage. High levels of more than one isoenzyme may indicate more than one tissue damage. Extremely high LDH levels may indicate a serious problem or multiple organ damage. Because LDH is found in many tissues, LDH levels alone are not sufficient to determine the location of tissue damage. For example, elevated LDH-4 and LDH-5 may be seen in cases of heart disease or muscle injury. However, this indicator is not sufficient for diagnosis.

Once specific amounts in the blood are diagnosed, your LDH level may be measured regularly to monitor the progress of your treatment. LDH is also frequently used to predict and monitor outcomes during treatment for some cancers. Conditions that usually cause high LDH include:

• Anemia
• kidney disease
• lung disease
• liver disease
• muscle injury
• Which dystrophies?
• broken bone
• Heart attack
• pancreatitis
• Some infections, including meningitis, encephalitis, mononucleosis (mono), and HIV
• Certain types of cancer, including metastatic melanoma, multiple myeloma, lymphoma, testicular cancer, and leukemia

A higher-than-normal LDH level may also mean that cancer treatment is not working. In addition, if your red blood cells are lysed during sample collection LDH height visible. However, this would be the wrong conclusion. If your results show high LDH levels, your doctor may order more tests to make a diagnosis.

If your test results show that you have high LDH levels, this does not necessarily mean that you have a medical condition. LDH levels may appear high during heavy exercise and the use of certain medications. When interpreting your results, your doctor: It considers several factors, including your current medications, medical history, and symptoms.

What Does Low LDH Mean?

It is rare for the test result to be lower than normal. Lower-than-normal LDH levels may be a symptom of a very rare genetic condition called lactate dehydrogenase A deficiency (glycogen storage disease XI) or lactate dehydrogenase B deficiency. Two types of genetic changes low LDH visible. People with the first type experience fatigue and muscle pain, especially during exercise. Those with the second type may have no symptoms. You can also have low LDH levels when you consume large amounts of ascorbic acid (vitamin C).