ABSTRACT
Pathogenesis and Epidemiology ITP is due to antibodies binding to platelet proteins, most often to the platelet
receptor GP Ilb/IIIa. These antibody-coated platelets then bind to Fc receptors in macrophages and are ingested. The initiating event in ITP is unknown. It is specu lated that the host responds to a viral or bacterial infection by creating antibodies which cross-react with the platelet receptors. Continued exposure to platelets per petuates the immune response. ITP that occurs in childhood appears to be an acute response to a viral infections and usually resolves. ITP in adults may occur in any age group but is seen especially in young women. Adult ITP can resolve in 30% of patients but may require splenectomy or chronic therapy.
