Platelet life-span and sites of platelet sequestration in onyalai.

With radioactive chromium, platelet kinetic studies were carried out in four patients with onyalai, a form of thrombocytopenic purpura occurring in the African Negro. Results were compared with those of White patients suffering from idiopathic thrombocytopenic purpura. In the onyalai patients platelet life-span was considerably reduced, and this was associated with a definite rise in radioactivity over the spleen in three of the four cases. In two patients remission was associated with steroid therapy, while in the other two remission followed splenectomy after steroids had failed to raise the platelet count. These findings are similar to those in White patients with idiopathic thrombocytopenic purpura.