ABSTRACT
Platelets play a central role in the maintenance of normal hemostasis and vascular repair. A decrease in platelet number, thrombocytopenia, can result in bruising, petechiae or even life-threatening bleeding. Immune-mediated thrombocytopenic purpura (AITP) is one of the most common forms of autoimmune disease affecting both adults and children. Patients with this disease develop autoantibodies that bind to platelet membrane antigens mediating the rapid destruction of antibody-coated cells in the reticuloendothelial system, particularly the spleen and liver. Sensing a decrease in circulating thrombocytes, the bone marrow responds with an increase in platelet production. Specific marrow progenitors, the megakaryocytes, increase in both number and ploidy to compensate for a shortened platelet life span.
