Coexpression of c-KIT and FLT3 Receptors in Patients with AcuteMyeloid Leukemia

Abstract

Acute myeloid leukemia (AML) is a clonal HSC disorder, characterized by arrested differentiation, inappropriate proliferation and survival of immature myeloid progenitors. The AML has the lowest survival rate of all leukemias, so, assessment of the prognostic factors in AML is very important. The characterization of AML is a multi-disciplinary process. It requires the integration of clinical informations, morphology, cytochemistry, IPT, cytogenetic diagnostic techniques. It is only by bringing all these modalities together that a clear picture can be presented. FLT3 mutationsare one of the most frequent somatic alterations in AML which was stated to confer an unregulated proliferative character to mutated blasts. In addition the FLT3 protein is expressed on blast cells from most AML. Thus it was proposed that FLT3 receptor (CD135), together with c-KIT receptor (CD117) play an important role in the proliferation, differentiation and survival of normal and leukemic hematopoietic tissues. The present study aimed to assess CD135 + CD117 co expression in patients with AML, and to evaluate their relation to disease outcome and positivity of FLT3-ITD. The current study was carried out on 50 newly diagnosed AML patients. All patients were subjected to complete history taking, thorough clinical examination and laboratory investigations including: CBC count, BM aspiration with examination of Leishman-stained PB and BM smears, IPT and detection of the level of CD135 & CD117 expressions & CD135+CD117 coexpression by FCM. The results showed that CD135 was expressed in 46% patients of patients. It was not correlated with any of the studied laboratory data except for CD34 (p=0.044) & BM blasts (p=0.001).CD117 was expressed in 74% patients of the studied AML cases & high significant correlation was found between CD117 expression and TLC & CD34 (p=0.002, p=0.004, respectively). Also it showed significant correlation with BM blasts (P=0.03).