title: Assessment of Helicobacter pylori eradication in patients on NSAID treatment.
abstract: BACKGROUND
  In this post-hoc analysis of a randomized, double blind, placebo controlled trial, we measured the sensitivity and specificity of Helicobacter pylori IgG-antibody titer changes, hematoxylin and eosin (H&E) stains, immunohistochemical (IHC) stains and culture results in NSAID using patients, following H. pylori eradication therapy or placebo.
  
  
  METHODS
  347 NSAID using patients who were H. pylori positive on serological testing for H. pylori IgG-antibodies were randomized for H. pylori eradication therapy or placebo. Three months after randomization, gastric mucosal biopsies were taken for H. pylori culture and histological examination. At 3 and 12 months, blood samples were taken for repeated serological testing. The gold standard for H. pylori infection was based on a positive culture or both a positive histological examination and a positive serological test. Sensitivity, specificity and receiver operating curves (ROC) were calculated.
  
  
  RESULTS
  H. pylori eradication therapy was successful in 91% of patients. Culture provided an overall sensitivity of 82%, and 73% after eradication, with a specificity of 100%. Histological examination with either H&E or IHC stains provided sensitivities and specificities between 93% and 100%. Adding IHC to H&E stains did not improve these results. The ROC curve for percent change in H. pylori IgG-antibody titers had good diagnostic power in identifying H. pylori negative patients, with an area under the ROC curve of 0.70 (95 % CI 0.59 to 0.79, P = 0.085) at 3 months and 0.83 (95% CI 0.76 to 0.89, P < 0.0001) at 12 months. A cut-off point of at least 21% decrease in H. pylori IgG-antibody titers at 3 months and 58% at 12 months provided a sensitivity of 64% and 87% and a specificity of 81% and 74% respectively, for successful eradication of H. pylori.
  
  
  CONCLUSIONS
  In NSAID using patients, following H. pylori eradication therapy or placebo, histological examination of gastric mucosal tissue biopsies provided good sensitivity and specificity ratios for evaluating success of H. pylori eradication therapy. A percentual H. pylori IgG-antibody titer change has better sensitivity and specificity than an absolute titer change or a predefined H. pylori IgG-antibody titer cut-off point for evaluating success of H. pylori eradication therapy.
authors.affiliation: Arthritis Center Twente, Department of Rheumatology and Clinical Immunology, Medisch Spectrum Twente Hospital and University of Twente, P,O, Box 50,000, 7500 KA, Enschede, The Netherlands. h.vonkeman@mst.nl
authors.forename: Harald E
authors.initials: HE
authors.lastname: Vonkeman
authors.forename: Htji
authors.initials: H
authors.lastname: Deleest
authors.forename: Mafj
authors.initials: M
authors.lastname: van Delaar
authors.forename: J
authors.initials: J
authors.lastname: Vanbaarlen
authors.forename: Kss
authors.initials: K
authors.lastname: Steen
authors.forename: Wf
authors.initials: W
authors.lastname: Lems
authors.forename: Jwj
authors.initials: J
authors.lastname: Bijlsma
authors.forename: Ej
authors.initials: E
authors.lastname: Kuipers
authors.forename: Hhml
authors.initials: H
authors.lastname: Houben
authors.forename: M
authors.initials: M
authors.lastname: Janssen
authors.forename: Bac
authors.initials: B
authors.lastname: Dijkmans
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D000907:Antibodies, Bacterial / Q000097:blood; D004311:Double-Blind Method; D005260:Female; D005753:Gastric Mucosa / Q000187:drug effects / Q000382:microbiology / Q000473:pathology; D016481:Helicobacter Infections / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000473:pathology; D016480:Helicobacter pylori / Q000187:drug effects*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000907:Antibodies, Bacterial; D007074:Immunoglobulin G