Immune thrombocytopenic purpra(ITP) is an autoimmune thrombocytopenic syndrome characterized by decreased platelet count and increased risk of bleeding, primarily due to immunoglobulins G(IgG)autoantibodies opsonizing the individual's platelets,resulting in markedly enhanced Fc receptors(FcR)-mediated phagocytosis and destruction by macrophages in the reticuloendothelial system within spleen Severe ITP defined as :Patients who have clinically relevant bleeding that mean that patients have bleeding symptoms at presentation sufficient to mandate treatment,or occurrence of new bleeding symptoms requiring additional therapeutic intervention with a different platelet-enhancing agent or an increased dose.