Cell surface expression of CD25 antigen (surface IL-2 receptor α-chain) is not a prognostic marker in chronic lymphocytic leukemia: results of a retrospective study of 281 patients.

Using the database of the Israeli CLL Study Group, we investigated the incidence and prognostic significance of CD25 expression on the surface of lymphocytic leukemia cells. Strong CD25 expression was found in 46 (16.4 %) of 281 tested cases and was correlated with the presence of splenomegaly (p = 0.04), expression of CD38 antigen (p = 0.001), and FMC-7 (p = 0.04). Age, gender, Binet stage, circulating lymphocyte count, presence of anemia or thrombocytopenia, atypical cell morphology, serum beta 2-microglobulin level, and ZAP-70 expression did not differ in patients with or without cell surface CD25. There was no correlation between CD25 expression and time to first treatment or overall survival. CD25 expression does not appear to be a prognostic factor in CLL.