Lactate dehydrogenase

5 mL blood in lithium heparin or plain tube.

Spectrophotometry.

Method and age dependent. See Table 6.

Of no value in the diagnosis of Myocardial infarction.

It is occasionally useful in the assessment of patients with liver disease or malignancy (especially lymphoma, seminoma, hepatic metastases); anaemia when haemolysis or ineffective erythropoiesis is suspected.

Although it may be elevated in patients with skeletal muscle damage it is not useful in this situation.

The ubiquitous tissue distribution of LD makes it a non-specific indicator of disease.

Increased levels are found in Myocardial infarction, Liver disease, haemolysis, ineffective erythropoiesis, some malignancies (especially Lymphoma (non-Hodgkin), muscle disease, and numerous other disease processes involving tissue damage.

Haemolysis during collection, delays in processing, or refrigeration of unseparated blood may cause an artefactual increase in enzyme activity. See Table 1.