الفهرس 
LeukemiaOnly 14 pages are availabe for public view
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Abstract
Acute myeloid leukemia (AML) is a clonal hematopoietic disorder that may be derived from either a hematopoitic stem cell or a lineage specific progenitor cell, characterized by arrested differentiation, in appropriate proliferation and predominance of immature myeloid precursor in the bone marrow and peripheral blood. AML is clinically heterogenous disease, with marked differences in survival following intensive chemotherapy. So, identification of new prognostic markers might be of therapeutic benefit. Many clinical features are associated with a poor out come in AML patients include advanced age, high leukocyte count, extramedullary mass and a history of proceeding haematological disorder such as myelodysplastic syndrome. However, prognosis for the majority of patients with AML remains dismal and identification of novel markers for risk stratification and therapeutic targeting is needed. CD47 is a transmembrane glycoprotein, which is widely expressed in several human tissues and functions as a ligand for many receptors, including signal regulatory protein alpha (SIRPα) CD47 has been shown toparticipate in cellular processes such as apoptosis, proliferation, adhesion, and migration. In particular, CD47 functions as a markerof ‘‘self’’ by inhibiting phagocytosis of autologous cells through interaction with SIRPα expressed by professional phagocytes, suchas macrophages. Furthermore, it plays a key role in immune and angiogenic responses. CD47 is broadly expressed in human cells and has been found to be overexpressed in many different tumor cells. The present study aimed to evaluate the prognostic value of CD47 expression in acute myeloid leukemic patients. The current study was carried out on 40 adults newly diagnosed AML patients who were classified into two groups; positive CD47 included 12 patients and negative CD47 included 28 patients. They were subjected to complete history taking, clinical examination, CBC, Bone marrow aspiration and Flowcytomyetric immunophenotyping. CD47 expression on blast cells was assessed by flow cytometry. There was no significant difference with the studied laboratory variables such as HB,WBCs count ,Platelets count, Blast in peripheral blood and bone marrow , ESR and LDH between CD47 negative and positive group. It was found that patients with high CD47 expression had a significant lower CR rate, significant higher relapse and death rates. Thus, there was a significant association between CD47 expression and poor outcome of patients. It was found that there is a significant decrease in both overall survival and disease free survival in positive CD47 expression group as compared with negative CD47 expression group. from this Study, we concluded that: 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 assessment of AML patients.