Significance of CD200 expression in patients with acute myeloid leukemia and its correlation with other prognostic markers

Background and Objectives : Acute myeloid leukemia (AML) known as cancer of blood and bone marrow is regarded as the commonest acute leukemia in adult patients. characterized by uncontrolled proliferation of hematopoietic progenitor cells with arrest of maturation and disruption of normal hematopoiesis. CD200 is a protein belonging to the immunoglobulin superfamily, it has an immunosuppressant effect by interacting with its receptor (CD200R). Aim: The main aim of this study is to investigate the expression of CD200 on leukemic myeloid cells. Various molecular prognostic markers and other clinical and laboratory findings were studied in relation to CD200 expression. Patients and Methods : The present study was conducted on newly diagnosed AML patients attending the adult Hematology/Oncology Clinic of the National Cancer Institute. The expression of CD200 was determined by flow cytometry using anti-CD200 monoclonal antibodies. CD200 expression considered positive if ≥20% and negative if <20%. Results : CD200 positive expression was found in 62/104 (59.5%) patients, CD200 was more expressed in CD34 positive cases (P= 0.012) and cases with gum hyperplasia (P= 0.046). FLT3/ITD mutation and NPM mutation were less detected in AML patients with positive CD200 (p=0.045 and p= 0.036 respectively). We found a statistically significant relation between inv16 and CD200 positive expression (p=0.005). Conclusion : CD200 could be used as a biological biomarker in AML pathophysiology, and could be incorporated in the initial diagnostic workup in patients treated within clinical trials for the discovery of new therapy which target malignant leukemic cells without harming other cells in AML.