From the Guidelines
The primary purpose of a lactate dehydrogenase (LDH) lab test is to aid in the prognosis of chemotherapy-naïve patients with histopathologically diagnosed metastatic germ cell tumors, as stated in the American Society of Clinical Oncology clinical practice guideline 1. The LDH test measures the amount of LDH enzyme in the blood, which can be elevated in various conditions, including cellular lysis or injury. Some of the causes of elevated LDH levels include:
- Strenuous exercise
- Liver disease
- Myocardial infarction
- Kidney disease
- Hemolysis
- Pneumonia According to the guideline, almost anything that results in cellular lysis or injury can cause elevations of LDH 1. However, the only proven utility of LDH is for prognosis of chemotherapy-naïve patients with histopathologically diagnosed metastatic germ cell tumors. Key points to consider when interpreting LDH test results include:
- Elevated LDH levels indicate tissue damage, but do not specify the exact location or cause
- Additional tests are usually needed for a definitive diagnosis
- Normal LDH values typically range from 140-280 units per liter (U/L), though reference ranges may vary between laboratories It is essential to note that LDH exists in five different forms (isoenzymes), and measuring specific isoenzymes can help pinpoint which organs or tissues are damaged. Nevertheless, the primary purpose of the LDH test, as per the guideline, is for the prognosis of metastatic germ cell tumors 1.
From the Research
Purpose of Lactate Dehydrogenase Lab
The purpose of a lactate dehydrogenase (LDH) lab is to measure the levels of LDH in the blood or other bodily fluids. This enzyme is found in many tissues and organs, including the liver, heart, and muscles.
- LDH is an important diagnostic biomarker for various diseases, including cancer, thyroid disorders, and tuberculosis 2.
- Abnormal levels of LDH in the blood can indicate tissue damage or disease, such as liver disease or acute liver failure 3, 4.
- The lab test can help doctors diagnose and monitor conditions such as liver disease, cancer, and other disorders that affect the liver or other organs.
- LDH levels can also be used to monitor the effectiveness of treatment for certain conditions, such as cancer or liver disease.
Clinical Significance
The clinical significance of LDH lab tests includes:
- Diagnosing and monitoring liver disease, including liver fibrosis, non-alcoholic fatty liver disease, and hepatocellular carcinoma 3.
- Detecting and monitoring cancer, including tumors that produce high levels of LDH 2.
- Evaluating tissue damage or disease in other organs, such as the heart or muscles.
- Monitoring the effectiveness of treatment for certain conditions, such as cancer or liver disease.
Diagnostic Applications
The diagnostic applications of LDH lab tests include:
- Measuring LDH levels in the blood or other bodily fluids to diagnose and monitor various diseases.
- Using LDH as a biomarker to detect and monitor cancer, liver disease, and other conditions.
- Evaluating the effectiveness of treatment for certain conditions by monitoring changes in LDH levels over time 4.