Immunophenotypic Characterization of the Leukemic B-cells from Iranian Patients with Chronic Lymphocytic Leukemia: Association between CD38 Expression and Disease Progression

Patients with B-cell chronic lymphocytic leukemia (B-CLL) have heterogeneous clinical courses, thus several biological parameters need to be added to the current clinical staging systems to predict disease outcome. Recent immunophenotypic studies performed mainly in Western populations have demonstrated the prognostic value of CD38 and ZAP-70 expression in B-CLL. To investigate the expression pattern of a variety of membrane antigens on leukemic cells from Iranian patients with CLL and to find out if there are any differences in the expression of these markers between indolent and progressive groups. In the present study, peripheral blood samples from 87 Iranian patients with B-CLL were analysed by flow cytometry. In all cases, the neoplastic cells displayed B-CLL phenotype (CD5+/CD19+/sIg+). The vast majority of the cases expressed CD23, but failed to stain for CD3 or CD14. The leukemic cells of most patients expressed CD27 (84/87, 95.4%) and CD45RO (74/87, 83.9%) molecules, suggesting a memory B-cell phenotype. Comparison between the indolent (n=42) and progressive (n=37) patients revealed significantly higher frequency and intensity of CD38 expression in progressive group (40.5%) compared to indolent (11.9%) patients (p<0.05). None of the other membrane antigens were differentially expressed in these two groups of patients. Our results obtained in an Asian ethnic population confirm and extend previous findings obtained from Western populations regarding the association of CD38 expression and disease progression in B-CLL.