Direct or reverse correlations within the expression of activation, differentiation or T-B cooperation molecules on chronic lymphocytic leukemia B cells.
AIM: B-cell chronic lymphocytic leukemia (B-CLL) is characterized by homogeneous coexpression of CD19, CD23 and CD5, and poor expression of membrane Ig. The aim of this study was to evaluate, in B-CLL patients and in healthy subjects by flow cytometry, B cell expression of surface molecules involved in cell activation, differentiation, T-B cooperation and apoptosis. METHODS: The study population consisted of 29 patients (16 men and 13 women; mean age: 66.5 years) with B-CCL. The control group consisted of 16 sex- and age-matched healthy subjects. The results are reported as percentages and mean fluorescence intensity (MFI) of CD19+ cells coexpressing each analyzed molecule. RESULTS: We found that the lymphocyte activation markers, CD69, CD25 and CD11c, were more expressed in B-CLL patients than controls. CD38 and CD95 expressions were higher on normal B lymphocytes than leukemic B cells. Finally, CD80 and CD86, molecules involved in T-B cooperation, showed an inverse expression between lymphocytes of B-CLL patients and healthy subjects. CD80 was higher on normal than leukemic B cells, while CD86 expression was higher on CLL B cells. Linear regression analysis showed a positive correlation between CD80 and CD95 expression on leukemic B cells; a reverse correlation was observed between CD69 and CD11c. CONCLUSION: These results suggest that common mechanisms may regulate the simultaneous expression of CD80 and CD95 or the reverse expression of CD69 and CD11c, respectively, in different stages of B cell activation and/or differentiation.