Activity of adenosine deaminase and of purine nucleoside phosphorylase in peripheral lymphocytes from patients with acquired immunological disorders.

The activity of adenosine deaminase (ADA) and of purine nucleoside phosphorylase (PNP) was determined in the peripheral lymphocytes of patients with diseases associated with acquired partial dysfunction of the immune response. Increase ADA activity was found in patients with Waldenstrom's macroglobulinemia and in some patients with non-Hodgkin's lymphoma. Increased PNP activity was found in patients with non Hodgkin's lymphoma whereas decreased PNP activity was fund in patients with connective tissue disorders. The alternations found in ADA and PNP activities probably reflect changes in the lymphocyte subpopulations and do not seem to have an etiological role in the pathogenesis of the disturbed immune response.