Correlation with HLA class II alleles and eradication treatment for Helicobacter pylori infection in patients with idiopathic thrombocytopenic purpura

Abstract

Idiopathic thrombocytopnenic purpura (ITP) is a disease caused by circulating autoantibodies that react with platelet membrane． Many authors have recently found a positive correlation between Helicobacter pylori infection and ITP. In order to clarify the pathogenic mechanism of Helicobacter pylori -associated ITP, we have investigated 72 ITP patients for Helicobacter pylori infection and HLA class II alleles. Fourty-six ITP patients (63.9%) were infected by Helicobacter pylori and bacterium eradication was accompanied by a long-term platelet response in 26 (56.5%) of them. The ITP patients with Helicobacter pylori infection showed DRB1*0405, DRB1*0410, DQB1*0401, DQB1*0402 frequencies significantly higher and DRB1*0901, DQB1*0303 frequencies significantly lower than in Helicobacter pylori-negative patients. Moreover, an DQB1*0301 was associated with a higher probability of platelet response to eradication treatment. These results suggest that the response to eradication in some ITP patients are likely to associate with HLA class II allele.