Cell surface expression of CD25, CD54, and CD95 on B- and T-cells in chronic lymphocytic leukaemia in relation to trisomy 12, atypical morphology and clinical course

Background: Surface antigen expression can be used to define subgroups of patients with different clinical courses in chronic lymphocytic leukaemia of the B-cell type (CLL). Purpose-Methods: To study the clinical significance of functional markers linked to proliferation (CD25), adhesion (CD54), and apoptosis (CD95) on B- and T-cells in 68 patients with CLL using dual colour flow cytometry (FCM). Results: The mean proportion of CD19(+) B-cells expressing CD25 was significantly higher in CLL patients compared to controls (P = 0.02), while CD54(+) and CD95(+) B-cells did not differ significantly. In CLL with atypical morphology and in patients with trisomy 12, the mean percentage of CD25(+) B-cells was lower than in typical CLL (P < 0.02) and in patients with disomic tumor cells (P < 0.03). Patients with greater than or equal to 30% of CD25(+) B-cells had a shorter median time to treatment than CD25-negative cases (P = 0.01). A low CD54 expression was associated with a prolonged median time to treatment (P = 0.004), low WBC counts (P < 0.05), and low S-LDH (P = 0.03). A high CD95 expression was correlated with elevated S-LDH (P = 0.02) and a finding of lymphadenopathy (P = 0.02). In individual patients there was a strong correlation between B- and T-cell expression of CD25 (P < 0.0001), CD54 (P = 0.0002), and CD95 (P = 0.0002), respectively. Conclusions: CD25 and CD54 expression on CD19(+) cells seems to give prognostic information. The strong correlation between the expression of CD25, CD54 and CD95 on B-and T-cells suggests that the expression of these antigens is not an inherent characteristic of the malignant B-cell clone.