Relative importance of CD38 expression over myeloid-associated markers expression in predicting the clinical course of B-CLL patients.

Expression of CD38 or myeloid-associated markers has been reported to be important in predicting prognosis in B-cell chronic lymphocytic leukemia (B-CLL) in separate studies but the impact of combining these markers on prognosis has not been examined. The current study aimed to evaluate the relative contribution of expression of CD38 and/or myeloid-associated markers (CD11b, CD13, CD15 and CD33) by flow cytometry (FCM) on the clinical course of 24 B-CLL patients. B-CLL patients with high levels of CD38 expression, defined as greater than or equal to 30% of neoplastic lymphocytes expressing CD38, had a significantly poorer OS than those with low levels of CD38 expression (54% cumulative survival: 51 months vs. 103 months, Kaplan-Meier survival analysis, p < 0.005, Logrank test). High levels of expression of myeloid-associated markers showed no statistically significant impact on OS in these patients. Ten of 11 patients (91%) with high levels of CD38 expression required chemotherapy. In contrast, only 5 of 13 patients (38%) with low levels of CD38 expression required chemotherapy (p < 0.009, Chi Square). There was no significant difference in the requirement for chemotherapy between patients with high levels of expression of myeloid-associated marker and those without (5/8 or 63% vs. 10/16 or 63%). Thus, our results suggest that CD38 is superior to myeloid-associated markers in predicting the prognosis of patients with B-CLL. Further studies with a larger sample size are indicated to confirm our observation.