Influence of Low Dose rIL-2 Treatment on Endogenous Cytokine Production, Expression of Surface IL-2R and The Level of Soluble IL-2R in Patients With Minimal Residual Disease

Abstract

This study was designed to investigate the immunomodulatory effect of low-dose IL-2 therapy (100 μ;g/day for 3 weeks) on interferon (IFN), tumor necrosis factor (TNF) production in vivo and in vitro and on the expression of IL-2Rα/β and soluble form of IL-2Rα. Patients enrolled in the study suffered from multiple myeloma (MM), Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL) All of them were in remission after chemotherapy or radiotherapy. Our results indicated that IL-2 given subcutanously at a low dose of 100 μ;g/day for 3 weeks induced IFN-γ and TNF-α in plasma (measured 24 hrs after the last dose of IL-2) and affected the ability of blood leukocytes to produce cytokines. Production of IFN-γ induced in vitro with PHA was enhanced, but TNF-a production induced by lipopolysaccharide (LPS) and virus (Newcastle Disease Virus) was depressed. The expression of both: surface IL-2R. especially β subunit on total population of lymphocytes and NK cells, and soluble form of IL-2R, α chain were significantly cahanced after low-dose IL-2 therapy. Low dose IL-2 therapy was well tolerated by all patients, and side effects not exceeding II grade of toxicity according to WHO scale were observed. Five patients with MM relapsed 3-10 month after cessation of IL-2 therapy. but all patients with Hodgkin's and non-Hodgkin's lymphomas are still in remission (20 months of observation).

Key Words:

• rIL-2 therapy
• IFN
• TNF
• IL-2R
• sIL-2 R