الفهرس 
Immune Thrombcytopnic PurpuraOnly 14 pages are availabe for public view
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Abstract
CD47 is a cell surface protein of the immunoglobulin (Ig) superfamily, which is heavily glycosylated and expressed by virtually all cells in the body. CD47 was first recognized as a 50 kDa protein associated and copurified with the integrin in placenta and Europhile granulocytes.
Platelet homeostasis is regulated by platelet expression of CD47 under normal conditions and in a mouse model of immune thrombocytopenia. Interaction between platelet CD47 and macrophage SIRPa is important in regulating normal platelet turnover and Fcg receptor mediated clearance of IgG-sensitized platelets. CD47- deficient platelets have a shortened half-life in the circulation of CD47 wild-type mice and are also more sensitive to Fcg receptor mediated clearance.CD47- and SIRPa-deficient mice are thrombocytopenic due to an increased rate of clearance of circulating platelets.
In the present study CD47 was measured in100 subjects that grouped into:
Group-I: included 30 adult patients diagnosed chronic non-responder ITP.
Group-II: included 30 adult patients diagnosed chronic responder ITP.
Group-III: included 30 adult patients newly diagnosed ITP.
Group-IV: included 10 sex and age matched healthy controls subjects.
In our study the level of CD47 was lowest among group I (10.9±5), CD47%(34±15) compared to group II was (161±64), CD47% (68±12), while group III was (59.2±20), CD47%(58±17) and controls was (193±30) and CD47% (65.1±9) with statistically high significant difference in between.
Also in our research we found statistically high significant difference between studied groups as regard platelet (per treatment), CD47 and CD47% in comparison to control group.
The level of CD47was lowest among group I patients who had lowest mean platelet count before and after treatment and highest number of relapses in comparison to other groups.
We found that There was statistically significant positive correlation between CD47 versus platelets in group III and no significance correlation versus other variables.
Previous finding consistent with Studies showed that CD47/SIRP α -signaling is important in regulating platelet uptake in ITP, the interaction between CD47 antigen on platelets and its ligand SIRPa on macophages play important role in platelet hemostasis.