[Role of costimulatory signals in idiopathic thrombocytopenia purpura: review].

Idiopathic thrombocytopenia purpura (ITP) is an autoimmune disease which is characterized by destruction of platelets by macrophages in the reticuloendothelial system. Recent studies suggest that ITP is related to the abnormal activation and apoptosis of T/B cells which lead to failure of immune tolerance. Now it is becoming clear that costimulatory signals are required for full T/B cell activation and assumed to modulate T/B cells responses as well as other aspects of the immune system. This review focuses on the role and state-of-the-art advancements of costimulatory signals in ITP.