Immunologic Findings in B-Chronic Lymphocytic Leukemia Patients Treated with α_2b-Interferon

Abstract

The immune function of seventeen previously untreated stage A, B-chronic lymphocytic leukemia (B-CLL) patients receiving α_2b-interferon (α_2b-IFN) was studied before therapy and three months later. In eleven patients a decrease of absolute blood lymphocyte numbers was observed, due to leukemic (CD5 +) cell reduction. No consistent changes in the number of T cells and their subsets were found. Immunoglobulin levels remained stable during therapy and serum β2-microglobulin levels increased (p< 0.001). In 13 patients high serum soluble interleukin-2 receptor (s-IL2R) levels were found (>x + 5sd of controls) which further increased during therapy (p<O.Ol), while in 5 patients high serum levels of soluble CD8 antigens were detected (> x + 5sd of controls) that did not change significantly during therapy. Interleukin-2 production by blood mononuclear cells, stimulated with phytohemaglutinin in vitro, was increased after IFN treatment in 5 patients and decreased in two. The in vivo immune findings and the in vitro response of B-CLL cells to α_2b-IFN (DNA, RNA, protein synthesis and morphological transformation) did not clearly correlate with the clinical effects of IFN.

Key Words:

• B-CLL, α_2b-IFN
• immunophenotype
• IL2 receptors
• lymphocyte
• transformation