Expression of myelomonocytic antigens in Egyptian B-cell chronic lymphocytic leukemia: impact on prognosis

Background: B-cell chronic lymphocytic leukemia (CLL) is a clonal malignancy of mature B cells that displays immense clinical heterogeneity. Therefore, there has been considerable interest in identifying prognostic markers that can be used to distinguish those patients who may have an aggressive form of CLL. Clinical staging systems lack the ability to predict disease progression. Numerous cellular and molecular markers with potential prognostic and therapeutic significance have been identified. Among these markers are the myelomonocyte-associated markers whose expression on neoplastic lymphocytes in CLL has been reported to correlate with an unfavorable prognosis.Aim of the study: We aimed to study the expression of the myelomonocytic markers CD13 and CD11b in Egyptian CLL patients in comparison with a healthy control group and assess their relation to other prognostic factors and patient outcomes. This study also aimed to reveal the association of CD38 and FMC7 with prognosis and disease progression.Participants and methods: Expressions of CD13 and CD11b were detected by flow cytometry in 30 newly diagnosed CLL cases and 10 healthy individuals. Percentages of CD38-positive and FMC7-positive cells were also measured.Results: CD13 was expressed in three cases (10%), whereas CD11b was expressed in four cases (13.3%) of CLL. CD38 was expressed in 13 cases (43.3%) and FMC7 in 11 cases (36.6%). None of the individuals in the healthy control group expressed CD13 or CD11b. The expression of CD13 and CD38 was significantly correlated with adverse results of complete blood count (P 0.05). CD11b expression was significantly associated with low platelet count (P=0.04). Expression of all studied markers (CD13, CD11b, CD38, and FMC7) was significantly correlated with the presence of 11q deletion (11qdel) (P=0.004, P 0.001, P=0.001, and P 0.001, respectively), diffuse pattern of bone marrow infiltration (P=0.005, 0.01, P 0.001, and P 0.001, respectively), and poor outcome (P=0.002, 0.01, P 0.001, and P 0.001, respectively). The expression of CD38 was also associated with the expression of CD13 and FMC7 (P=0.02 and P 0.001, respectively) and with the presence of trisomy 12 (P=0.01).Conclusion: CD13 and CD11b expressions were found to be correlated with the standard adverse prognostic factors in CLL and with shorter survival, which questions their future possible role as prognostic markers in CLL. FMC7 and CD38 expression was also associated with unfavorable prognosis and poor outcome.