Prognostic Impact of CD200 Expression in Pediatric B-Cell Acute Lymphoblastic Leukemia

Abstract

Background: Acute lymphoblastic leukemia (ALL) is a heterogeneous disease in which immature lymphoid cells proliferate mostly in bone marrow, peripheral blood, and other organs. Flow-cytometric immunophenotyping in childhood ALL assists in the diagnosis and subclassification of B- and T-lineages, as well as predicting outcomes of the disease. CD200 expression has many diagnostic and potentially prognostic implications in the flow-cytometric evaluation of lymphoid malignancies. Aim of Study: The aim of this study was to evaluate the expression of CD200, correlate its expression with hematological and clinical parameters, and assess patient's response to induction of chemotherapy in the newly diagnosed de novo pediatric B-cell ALL. Materials and Methods: This prospective cross-sectional study was conducted on 30 pediatric patients (<15 years) with newly diagnosed de novo B-cell ALL. Morphology, cytochemistry, and flow cytometry (FCM) of the peripheral blood and/or bone marrow were performed for all patients and the patients were re-evaluated morphologically at day 28 from the start of chemotherapy for assessment of complete remission achievement. Results: Majority of the patients (80%) had a positive expression of CD200. All patients were in high-risk group and had positive CD200 expression and majority of the them were responded to induction therapy. Conclusion: CD200 is frequently expressed and closely related to the high-risk groups; however, it cannot be considered as an independent poor prognostic marker as not all cases with positive CD200 had low response to induction therapy.