title: Effect of Helicobacter pylori eradication in patients with chronic idiopathic thrombocytopenic purpura-a randomized controlled trial.
abstract: OBJECTIVE
  Eradication of Helicobacter pylori was reported to increase the platelet counts in some H. pylori-positive patients with chronic idiopathic thrombocytopenic purpura (cITP). However, the efficacy of the eradication was quite different according to the previous reports. To determine whether H. pylori infection can contribute to cITP, we performed a randomized controlled trial for the first time. In addition, to investigate the possible pathogenic mechanisms and to predict the platelet response after eradication of H. pylori in each cITP patient, several H. pylori virulence factors, the urease activities of the infected H. pylori strains, and the titers of anti-CagA IgG antibodies were analyzed.
  
  
  METHODS
  Patients with cITP underwent gastroscopy and gastric H. pylori infection was confirmed by culture. H. pylori-positive cITP patients were randomly assigned to either the eradication or the non-eradication group. The eradication group received a standard antibiotic therapy for H. pylori. Response to treatment was defined as complete (CR) if the platelet count was above 150x10(3)/microl and partial (PR) if the platelet count increased by more than 50x10(3)/microl above the pretreatment count. The virulence factors were investigated by PCR and PCR-based direct sequencing. Anti-CagA IgG antibody titer of each patient's serum was measured by ELISA.
  
  
  RESULTS
  Of the 36 ITP patients, 25 (69.4%) were positive for H. pylori and eradication was achieved in 84.6% of these patients. The platelet response was significantly different between the eradication group (46.2%) and the non-eradication group (0%). No significant differences were found in clinical factors between the responders and the nonresponders. H. pylori virulence factors and the urease activity were not associated with the response. The titers of anti-CagA antibodies in the responders were significantly higher than those in the nonresponders (p=0.04).
  
  
  CONCLUSIONS
  H. pylori eradication treatment is a favorable therapeutic option for H. pylori-positive patients with cITP. Moreover, an ELISA titer of serum anti-CagA antibody may be a good predictor of platelet recovery, and immunological reaction between platelet and anti-CagA antibodies may have some relation to the pathogenesis of H. pylori-positive patients with cITP.
authors.affiliation: Division of Gastroenterology & Hepatology, Department of Internal Medical, Tokai University School of Medicine, Isehara, Kanagawa, Japan.
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Suzuki
authors.forename: Masashi
authors.initials: M
authors.lastname: Matsushima
authors.forename: Aya
authors.initials: A
authors.lastname: Masui
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Watanabe
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takagi
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Ogawa
authors.forename: Takayuki
authors.initials: T
authors.lastname: Shirai
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Mine
mesh_terms: D000900:Anti-Bacterial Agents; D000907:Antibodies, Bacterial / Q000276:immunology; D000942:Antigens, Bacterial / Q000097:blood / Q000276:immunology; D001426:Bacterial Proteins / Q000097:blood / Q000276:immunology; D001706:Biopsy; D001792:Blood Platelets / Q000187:drug effects / Q000502:physiology*; D002908:Chronic Disease; D004269:DNA, Bacterial / Q000235:genetics; D004359:Drug Therapy, Combination / Q000627:therapeutic use*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D005753:Gastric Mucosa / Q000382:microbiology / Q000473:pathology; D005773:Gastroscopy; D016481:Helicobacter Infections / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D016480:Helicobacter pylori / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D016133:Polymerase Chain Reaction; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000097:blood* / Q000150:complications; D012189:Retrospective Studies; D012720:Severity of Illness Index; D016896:Treatment Outcome; D014774:Virulence / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D004269:DNA, Bacterial; C080866:cagA protein, Helicobacter pylori