Ethnic and racial difference in Helicobacter pylori infection in patients with immune thrombocytopenia treated at a major urban medical center.

ABSTRACT

Immune thrombocytopenia (ITP) is an autoimmune disorder with a complex immunopathology and pathogenesis characterized by thrombocytopenia and bleeding manifestations. The disorder is separated into primary (idiopathic) ITP and secondary ITP, when associated with other immune or lymphoproliferative disorders and certain chronic infections. Helicobacter pylori (H. pylori) is a recognized bacterial cause of ITP. In regions with high prevalence of infection, bacterial eradication has resulted in improvement in platelet count. However, the prevalence of H. pylori infection and response to antimicrobial therapy in North American ITP patients is reportedly low. We evaluated the prevalence of H. pylori infection in ITP patients diagnosed and treated at a large urban medical center. Eighty-two patients were screened for H. pylori, by stool antigen (n = 54), H. pylori breath test (n = 11), and H. pylori antibodies (n = 16), of which 15 (18.3%) were white non-Hispanic (WNH), 55 (67%) Hispanic (H), 8 (9.8%) Asian (A), and 4 (4.9%) African-American (AA). Of the screened patients, 36/82 (43.9%) tested positive for H. pylori. The prevalence of H. pylori infection within the represented ethnic groups was 2/15 (13%) WNH, 29/55 (52.7%) H, 3/8 (37.5%) A, and 2/4 (50%) AA. There was a significant difference in prevalence of infection comparing WNH and H patients (p = 0.007). There were 36 treated patients, with H. pylori eradication documented in 26 patients. Fifteen of the 26 patients were evaluable for response with 8 of 15 (53%) having clinical responses, 6 complete responses, and 2 partial responses. Our study demonstrates an increased prevalence of H. pylori infection in the Hispanic ITP population with a reasonable platelet response among patients with H. pylori eradication.