From the Guidelines
Elevated lactate dehydrogenase (LDH) levels require a comprehensive workup to identify the underlying cause, and initial investigations should include a complete blood count, liver function tests, and imaging studies such as chest X-ray or CT scan, as recommended by recent guidelines 1. Further investigations for elevated LDH should focus on identifying the underlying cause, as LDH is a nonspecific marker released when cells are damaged.
- Initial workup should include:
- Comprehensive metabolic panel
- Complete blood count
- Liver function tests to assess for organ dysfunction
- Specific tests should be directed by clinical presentation and may include:
- Cardiac enzymes (troponin, CK-MB) if heart damage is suspected
- Imaging studies such as chest X-ray or CT scan to evaluate for pulmonary conditions or malignancies
- Hemolysis studies including peripheral blood smear, haptoglobin, and reticulocyte count if hemolytic anemia is a concern
- In cases where malignancy is suspected, appropriate cancer screening tests like CT scans, tumor markers, or tissue biopsies may be warranted, as suggested by guidelines for kidney cancer 1 and chronic lymphocytic leukemia 1.
- For suspected muscle disorders, creatine kinase levels should be checked. The timing and selection of these investigations should be guided by the patient's symptoms, medical history, and physical examination findings, as LDH elevation can result from damage to multiple organ systems including heart, liver, muscles, lungs, kidneys, and blood cells, and serial LDH measurements may also be useful to monitor disease progression or treatment response in certain conditions, such as primary cutaneous melanoma 1.
From the Research
Further Investigations for LDH Elevated
Elevated serum lactate dehydrogenase (LDH) levels can be an indicator of various diseases, including malignant lymphoma, cancer, and infection. The following investigations may be considered:
- Abdominal CT scan 2
- Explorative laparotomy 2
- Thorough work-up to determine the underlying cause of elevated LDH levels 2, 3
- Measurement of LDH isoenzymes to determine the specific type of LDH elevation 2
- Blood tests to rule out other causes of elevated LDH, such as liver disease or hemolysis 4, 3
- Imaging studies, such as PET or MRI, to evaluate for cancer or other diseases 3, 5
- Bone marrow biopsy to evaluate for hematologic malignancies 3, 6
Diagnostic Value of LDH
LDH has diagnostic value in the preclinical stage of malignant lymphoma 2 and can be a distinguishing biomarker for the presence of cancer, liver metastases, hematologic malignancies, and infection 3. However, LDH elevation is not specific to any particular disease and can be caused by various benign and malignant conditions 4.
Prognostic Value of LDH
Elevated LDH levels are associated with a poor prognosis in many cancer types, including multiple myeloma 6 and can be an independent predictor of mortality in admitted medical patients 3. High serum LDH levels can also identify subgroups of patients with very-high-risk multiple myeloma 6.