title: Long term changes in platelet counts after H. pylori eradication in non-ITP patients.
abstract: Helicobacter pylori eradication is becoming a first-line therapy against idiopathic thrombocytopenic purpura (ITP) and its long term efficacy has already been reported. In contrast, eradication therapy reduced peripheral platelets in non-ITP patients 8 weeks later. To confirm the long term efficacy of Helicobacter eradication on platelet counts in non-ITP patients, we evaluated changes in peripheral platelet counts in endoscopically diagnosed patients with Helicobacter infection. Endoscopically diagnosed patients with Helicobacter infection received eradication therapy using amoxicillin (1500 mg/day), clarithromycin (400 mg/day) and lansoprazole (60 mg/day). The changes in platelet counts after Helicobacter eradication were serially evaluated for as long as 3 years or more. In total, 294 patients were enrolled: 243 patients successfully received eradication therapy and 51 were unsuccessfully treated. As a whole, peripheral platelet counts significantly decreased after Helicobacter eradication, being reduced by more than 1.0 × 10⁹/l by 5-6 months, 1 year, 2 years and 3 years or more (from 24.2+/-5.6 to 23.1+/-5.0, 23.0+/-5.0, 22.1+/-4.5, 22.4+/-5.6, and 21.6+/-5.3 × 10⁹/l: p = <0.0001, <0.0001, 0.0001, 0.0052, and <0.0001, respectively). Helicobacter pylori eradication finally reduced peripheral platelet counts around 2.0 × 10⁹/l in non-ITP patients. There was a definite difference in platelet regulation by Helicobacter pylori between ITP and non-ITP patients. These bivalent effects, upregulation and downregulation, on the peripheral platelet induced by Helicibacter pylori infection appeared to originate from quite different mechanisms.
authors.affiliation: Division of Hematology and Rheumatology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan. m-2000@mbk.ocn.ne.jp
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Matsukawa
authors.forename: Maho
authors.initials: M
authors.lastname: Iwamoto
authors.forename: Kimitoshi
authors.initials: K
authors.lastname: Kato
authors.forename: Shigeaki
authors.initials: S
authors.lastname: Mizuno
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Gon
authors.forename: Akihiro
authors.initials: A
authors.lastname: Hemmi
authors.forename: Natalia
authors.initials: N
authors.lastname: Shirinskaya
authors.forename: Jin
authors.initials: J
authors.lastname: Takeuchi
authors.forename: Shigemasa
authors.initials: S
authors.lastname: Sawada
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles / Q000494:pharmacology / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000658:Amoxicillin / Q000494:pharmacology / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use; D000897:Anti-Ulcer Agents / Q000494:pharmacology / Q000627:therapeutic use; D017291:Clarithromycin / Q000494:pharmacology / Q000627:therapeutic use; D005260:Female; D016481:Helicobacter Infections / Q000097:blood* / Q000188:drug therapy; D016480:Helicobacter pylori / Q000187:drug effects; D006801:Humans; D064747:Lansoprazole; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000503:physiopathology*
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000900:Anti-Bacterial Agents; D000897:Anti-Ulcer Agents; D064747:Lansoprazole; D000658:Amoxicillin; D017291:Clarithromycin