CD38 expression level and pattern of expression remains a reliable and robust marker of progressive disease in chronic lymphocytic leukemia

Abstract

Chronic lymphocytic leukemia (CLL) follows a variable clinical course which is difficult to predict at diagnosis. We assessed somatic mutation (SHM) status, CD38 and ZAP-70 expression in 87 patients (49 male, 38 female) with stage A CLL and known cytogenetic profile to compare their role in predicting disease progression, which was assessed by the treatment free interval (TFI) from diagnosis. Sixty (69%) patients were SHM+, 24 (28%) were CD38+ and ten (12%) were ZAP-70+. The median TFI for: (i) SHM + versus SHM− patients was 124 versus 26 months; hazard ratio (HR) = 3.6 [95% confidence interval (CI) = 1.8 – 7.3; P = 0.001]: (ii) CD38− versus CD38+ patients was 120 versus 34 months; HR = 2.4 (95% CI = 1.4 – 5.3; P = 0.02); and (iii) ZAP70− versus ZAP70+ was 120 versus 16 months; HR = 3.4 (95% CI = 1.4 – 8.7; P = 0.01). SHM status and CD38 retained prognostic significance on multivariate analysis whereas ZAP-70 did not. We conclude that ZAP-70 analysis does not provide additional prognostic information in this group of patients.

Keywords:

• CLL
• IgV_H
• CD38
• ZAP-70
• prognostic factors