Study of CD 47 Expression in Patients with Acute Myeloid Leukemia

Background: Acute Myeloid Leukemia (AML) is the most common acute leukemia affecting adults, and its frequency increases with age. CD47 may not only be valuable biomarker to recognize leukemic stem cells (LSCs) but also may denote a clinically relevant pathogenetic factor of disease. The aim of this work was to study the expression of CD47 in patients with acute myeloid leukemia and to identify its role as a prognostic marker.

Methods: The present study was carried out on 40 newly diagnosed untreated AML patients. AML patients were divided into two groups according to status of expression: Negative Group including patients expressing CD47 on less than 20% of their blast cells (28 patients) and positive Group including patients expressing CD47 on 20 % or more of their blast cells (12 patients). All patients were subjected to laboratory investigation for detection of CD47 expression m bone marrow aspirate and venous blood samples of AML patients by flowcytometry.

Results: Complete remission was found in 2 patients (16.67%), 6 patients relapsed (50%) and 4 patients died (33.33%) of 12 cases that had exhibited CD47 positive expression. Kaplan-Meier Survival curve shows significant higher overall survival and disease-free survival in negative CD47 expression group than in positive CD47 expression group.

Conclusions: Positive CD47 expression levels are associated with a poor outcome in AML patients and its expression can be easily determined in routine flow cytometric analysis. Therefore, it should be regularly investigated as a bad prognostic factor for the assessment of AML patients.