title: Usefulness of serological IgG antibody determinations for confirming eradication of Helicobacter pylori infection.
abstract: OBJECTIVE
  Prior studies have suggested that IgG antibody titers may be useful to confirm successful treatment of Helicobacter pylori (H. pylori) infection. However, the diagnostic value of decreasing IgG titers is limited by the necessity to perform pre and posttreatment tests in parallel which requires stored sera. Our objective was to assess the accuracy of IgG antibody titers using the HM-CAP IgG EIA kit (Enteric Products) in monitoring treatment of H. pylori infection and to compare the relative accuracy of parallel versus serial determinations.
  
  
  METHODS
  The 14C urea breath test (UBT) was used to confirm H. pylori infection in 83 dyspeptic patients and eradication of the organism at 4 wk and 6 months posttreatment. IgG titers pretherapy and 6 months posttherapy were determined either serially (separate EIA plates) or in parallel (same EIA plate), and the relative percent decline in antibody titer was calculated.
  
  
  RESULTS
  When a decline of > or = 25% at 6 months was used as the cut-off for H. pylori eradication, mean sensitivities of serial and parallel determinations were 87.5% and 86.8%, respectively, and mean specificities of both were 100%. In 68 of 75 patients in whom the organism was eradicated, the mean decrease in IgG titer at 6 months was 41.1% for serial determinations and 41.5% for parallel determinations.
  
  
  CONCLUSIONS
  Serial or parallel IgG titers offer equivalent diagnostic accuracy for confirming H. pylori eradication after therapy. A > or = 25% decline in titer 6 months after therapy is a sensitive and specific marker for eradication of the infection. Serial evaluation of IgG titers does not require serum storage, and is a cost-effective and accurate alternative to the UBT or endoscopy-based methods.
authors.affiliation: Enteric Products, Inc., Stony Brook, New York 11790, USA.
authors.forename: P
authors.initials: P
authors.lastname: Marchildon
authors.forename: D H
authors.initials: DH
authors.lastname: Balaban
authors.forename: M
authors.initials: M
authors.lastname: Sue
authors.forename: C
authors.initials: C
authors.lastname: Charles
authors.forename: R
authors.initials: R
authors.lastname: Doobay
authors.forename: N
authors.initials: N
authors.lastname: Passaretti
authors.forename: J
authors.initials: J
authors.lastname: Peacock
authors.forename: B J
authors.initials: BJ
authors.lastname: Marshall
authors.forename: D A
authors.initials: DA
authors.lastname: Peura
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000897:Anti-Ulcer Agents / Q000627:therapeutic use; D000907:Antibodies, Bacterial / Q000097:blood*; D001944:Breath Tests; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D005756:Gastritis / Q000175:diagnosis / Q000188:drug therapy* / Q000276:immunology; D016481:Helicobacter Infections / Q000175:diagnosis / Q000188:drug therapy* / Q000276:immunology; D016480:Helicobacter pylori / Q000187:drug effects / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity
chemical_list: D000900:Anti-Bacterial Agents; D000897:Anti-Ulcer Agents; D000907:Antibodies, Bacterial; D007074:Immunoglobulin G