Prognostic value of serum lactic dehydrogenase in non-Hodgkin's lymphoma.

Lactic acid dehydrogenase (LDH) is a glycolytic enzyme that may be elevated in the serum of patients with non-Hodgkin's lymphoma (NHL). In this investigation LDH was assayed in sera from 155 untreated patients with NHL. Serum LDH (S-LDH) was found to be significantly correlated both to the spread of the disease and to the histological grade of malignancy i.e. more advanced disease or more aggressive histopathology was associated with higher S-LDH values. A high pretreatment S-LDH level (greater than 8.0 mukat/l) in stages III and IV correlated significantly to a decreased survival time. The patients with a pretreatment level of less than 8.0 mukat/l had an actuarial 2-year survival of 80%, compared to 30% in the patients with levels greater than 8.0 mukat/l (P less than 0.001). In stages I and II all 6 patients with a high pretreatment level (greater than 8.0 mukat/l) relapsed during or a short time after radiotherapy. In a longitudinal study of 24 patients it was found that S-LDH reflected in the clinical course. In patients treated to partial or complete remission, S-LDH decreased and at relapse it rose again. It is concluded that S-LDH might be useful both as a prognostic marker and to monitor the course of the disease.