Effect of Thymostimulin on Human Lymphocyte Adenosine Deaminase and Purine Nucleoside Phosphorylase Activities: Physiological and Therapeutic Effects

Abstract

Thymostimulin (TP1 — Serono), which has several immunobiological activities in vivo and in vitro, is a pool of thermostable polypeptides extracted from calf thymus and has been used in the treatment of primary and secondary immunodeficiencies (1, 2). However, the immunobiological properties and the mechanism of action of this cellular extract is still not completely understood. For this reason, we have studied the activity of thymostimulin on the intracellular levels of adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) enzymes in peripheral blood lymphocytes of patients with hematological malignancies. We also hoped to reveal the effects of thymostimulin on lymphocytes from cord blood and from elderly patients. In fact, these enzymes have important roles in both lymphocyte ontogenesis (3, 4) and in the maintenance of immunological functions (5, 6).