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.

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). 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 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. 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.