Immune thrombocytopenia in children.

Idiopathic thrombocytopenic purpura in the adult has a clearly established autoimmune etiology; IgG antiplatelet antibody is demonstrable on the patient's platelets and is frequently present in the serum. Platelet IgG is correlated inversely with the platelet count. In the acute childhood form of the disease, serum antibody is usually absent but increased IgG is present on the platelets, thus suggesting the immune nature of the childhood disease. The spleen acts as a significant source of antiplatelet antibody as well as the major reticulo-endothelial site for destruction of antibody-coated platelets. The majority of children with idiopathic (autoimmune) thrombocytopenia recover completely and have normal platelet counts within 6 months of diagnosis. Some patients recover after a longer period of time. Ten to 15 percent have a chronic form of the disease which is indistinguishable from the adult disease; splenectomy benefits approximately 70% of these patients.