Pyrimidine and purine activities in non-Hodgkin's lymphoma. Correlation with histological status and survival.

The levels of the purine catabolic enzymes, adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP), together with the pyrimidine activities, thymidine phosphorylase (TP) and thymidine kinase isozymes (TK) have been determined for cells obtained from solid lymphoid tissue of 38 patients with non-Hodgkin's lymphoma (NHL) and 14 individuals exhibiting benign reactive lymphoid hyperplasia. Within each NHL histological group subtyped according to the Rappaport classification, and in the reactive hyperplasia group, there was considerable variation in these activities. However, higher levels of TK and TP activities occurred in cells of the histologically unfavourable prognostic NHL groups compared with those of favourable histology or reactive hyperplasia. There was an inverse relationship between survival and elevated TK isozyme 1 and TP levels, which was independent of histological classification and clinical staging. These results indicate that, in addition to morphology, estimations of TK and TP of involved lymphoma cells in NHL is of clinical relevance.