Abstract

Platelet survival and splenic sequestration patterns were studied in 32 patients with thrombocytopenia using donor platelets labelled with chromium-51. A shorter mean platelet lifespan was observed in immune thrombocytopenia (ITP) (mean 12 hours) than in hypersplenism (mean 56 hours) or marrow hypoplasia (mean 102 hours). There was no such correlation between diagnosis and splenic sequestration. A biphasic survival curve was seen in nine of 22 patients with ITP. Thirteen patients underwent splenectomy with complete (9) or partial (4) response, but no consistent pattern of results was manifest. It is concluded that in vivo isotope studies are of little value in predicting the benefit of splenectomy in thrombocytopenic patients, although they may demonstrate the mechanism of the thrombocytopenia, in particular the biphasic survival curve revealing separate 'immune' and 'hypersplenic' components of platelet destruction in ITP.