Platelet kinetics in patients with idiopathic thrombocytopenic purpura and moderate thrombocytopenia

Abstract

We studied 10 normal subjects and 20 patients with stable, untreated idiopathic thrombocytopenic purpura (ITP) and platelet counts in the range of 35,000 to 110,000/μL. The diagnosis was made by clinical criteria. Platelet-associated IgG was increased in all 9 of the 9 patients studied. Autologous platelets were labeled with chromium 51 and reinfused for measurement of mean cell life and platelet production rate. Mean cell life was calculated by two methods, weighted mean and multiple hit, with excellent agreement between the two. As expected, mean cell life was significantly reduced in ITP patients as compared to the normal subjects (2.9 days v. 8.0 days, P