Genetic analysis of HLA- and HPA-typing in idiopathic (autoimmune) thrombocytopenic purpura patients treated with cepharanthin.

We performed genetic analysis of human leukocyte antigen (HLA) and human platelet antigen (HPA) in 45 patients with cepharanthin-treated idiopathic thrombocytopenic purpura. HLA-typing was performed by the polymerase chain reaction-restriction fragment length polymorphism method, and HPA-typing by a polymerase chain reaction-sequence-specific primer method. There were 14 responders and 31 nonresponders. Responders included many patients who had already been treated with prednisolone. HLA-DRB1*0901 was significantly more common in responders than in nonresponders. In contrast, HLA-DRB1*0410 and DQB1*0401 were significantly more common in nonresponders. The a/b genotype of HPA-2a/2a (Ko(b)/Ko(b)) was significantly increased in responders. In contrast, HPA-2a/2b (Ko(b)/Ko(a)) and HPA-3a/3b (Bak(a)/Bak(b)) were significantly more common in nonresponders. These findings suggest that genetic studies of HLA and HPA can predict the response of idiopathic thrombocytopenic purpura to cepharanthin.