Diagnostic value of CD117 in differential diagnosis of acute leukemias.

C-kit receptor (CD117) and its ligand, stem cell factor, play a key role in normal hematopoiesis. It has been demonstrated that its expression extremely increases in leukemias with myeloid commitment. We analyzed findings on CD117 expression together with other myeloid related markers in 203 de novo acute leukemias, referred to Iranian immunophenotyping centers: Iranian Blood Transfusion Organization (IBTO) and Baghiatallah Hospital (BH). All cases were characterized based on the French American British cooperative group (FAB) and European Group for Immunological Classification of Leukemias (EGIL). The cases comprised of 111 acute myeloblastic leukemia (AML), 86 acute lymphoblastic leukemia (ALL), and 6 acute undifferentiated leukemia (AUL). CD117 was positive in 75 % of AML and 50 % of AUL, whereas none of the ALL cases was positive for this marker. Although CD117 was positive in 100 % of M5a cases, no M5b positive was found (p = 0.036). The calculated specificity for myeloid involvement was 100 % for CD117 and CD33, and 98 % for CD13 and CD15 (p < 0.001). The calculated sensitivity for myeloid involvement was 83, 76, 64, and 41 % for CD13, CD117, CD33, and CD15, respectively (p < 0.001). We concluded that CD117 expression is a specific and rather sensitive marker for differential diagnosis between AML and ALL, and except for M5 subtypes, it fails to determine FAB subtypes; lack of expression in M5 can identify M5b. Therefore, it should be included in the routine primary panel for diagnosis of acute leukemias.

Flow cytometric evaluation of red blood cell chimerism after bone marrow transplantation in Iranian patients: a preliminary study.

The aim of this study was to evaluate mixed red cells population and red blood cell chimerism after hematopoietic stem cell transplantation. Red blood cell chimerism after hematopoietic stem cell transplantation was analyzed using a series of fluorescein isothiocyanate-conjugated monoclonal antibodies (BioAtlantic, France) directed against ABH, Rh (D, C, E, c, e), Kell, Duffy, Kidd, and Ss antigens on blood samples of 14 patients with hematologic disorders undergoing hematopoietic stem cell transplantation, by flow cytometric method on days 15, 30, and 60 after transplantation. All patients showed expression of donor red cell antigens within days 15 - 30 after hematopoietic stem cell transplantation. Graft versus host disease and ABO incompatibility did not affect the expression of chimerism. Flow cytometric analysis is a simple, accurate, and valuable test which is of significant help in monitoring chimerism in allogeneic hematopoietic stem cell transplantation.