title: Platelet count response to H. pylori treatment in patients with immune thrombocytopenic purpura with and without H. pylori infection: a systematic review.
abstract: Eradication of H. pylori improves thrombocytopenia in some patients with immune thrombocytopenic purpura by mechanisms that remain obscure. Platelet count responses may occur independently of H. pylori infection as a result of the immune modulating effects of macrolide antimicrobials or the removal of other commensal bacteria. We performed a systematic review of the literature to determine the effect of H. pylori eradication therapy in patients with immune thrombocytopenic purpura by comparing the platelet response in patients who were, and who were not infected with H. pylori. MEDLINE, EMBASE, Cochrane central registry and abstracts from the American Society of Hematology (from 2003) were searched in duplicate and independently without language or age restrictions. Eleven studies, 8 from Japan, were included enrolling 282 patients with immune thrombocytopenic purpura who received eradication therapy; 205 were H. pylori-positive and 77 were H. pylori-negative. The odds of achieving a platelet count response following eradication therapy were 14.5 higher (95% confidence interval 4.2 to 83.0) in patients with H. pylori infection (51.2% vs. 8.8%). No study reported bleeding or quality of life. Adverse events were reported in 12 patients. H. pylori eradication therapy was of little benefit for H. pylori-negative patients. These findings strengthen the causal association between H. pylori infection and immune thrombocytopenia in some patients. Randomized trials are needed to determine the applicability of H. pylori eradication therapy across diverse geographical regions.
authors.affiliation: 1Michael G DeGroote School of Medicine, Department of Medicine, McMaster University, Hamilton, Ontario, Canada. arnold@mcmaster.ca
authors.forename: Donald M
authors.initials: DM
authors.lastname: Arnold
authors.forename: Ashley
authors.initials: A
authors.lastname: Bernotas
authors.forename: Ishac
authors.initials: I
authors.lastname: Nazi
authors.forename: Roberto
authors.initials: R
authors.lastname: Stasi
authors.forename: Masataka
authors.initials: M
authors.lastname: Kuwana
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: John G
authors.initials: JG
authors.lastname: Kelton
authors.forename: Mark A
authors.initials: MA
authors.lastname: Crowther
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D016481:Helicobacter Infections / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D016480:Helicobacter pylori / Q000187:drug effects*; D006801:Humans; D010976:Platelet Count; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000097:blood / Q000188:drug therapy* / Q000209:etiology; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents