Lactate dehydrogenase (LDH)

What it measures

LDH is an enzyme present in almost every tissue. A raised level indicates tissue damage or high cell turnover and is used in haemolysis work-up, lymphoma and germ-cell tumour follow-up, and liver disease.

Specimen and preparation

• Specimen: Serum or lithium-heparin plasma
• Tube: Gold top
• Preparation: Haemolysis strongly increases LDH; separate serum promptly and do not refrigerate whole blood.

Reference range

Reference ranges differ between laboratories, methods and populations. Always use the range printed on your own lab report.

Causes of high values

• Haemolytic and megaloblastic anaemia
• Lymphoma, leukaemia and other tumours
• Liver disease, especially ischaemic
• Muscle injury
• Pulmonary infarction and severe infections
• Haemolysed specimen

Method

Kinetic UV assay (lactate to pyruvate, IFCC)

Good to know

LDH is non-specific; interpret with haptoglobin, bilirubin and the clinical picture. Also used as a tumour marker for burden in lymphoma and testicular cancer.

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