title: Accuracy of serology for the diagnosis of Helicobacter pylori infection--a comparison of eight kits.
abstract: OBJECTIVE
  To determine the accuracy of eight commercially available kits for the serological diagnosis of Helicobacter pylori infection, and hence whether a serology service could be introduced to reduce endoscopy workload.
  
  
  METHODS
  Eighty four patients newly presenting to their general practitioners with dyspepsia were recruited. Gold standard diagnosis of H pylori infection was obtained both by a histological examination of gastroduodenal biopsy specimens and by the 14C-urea breath test (UBT). The performance of six quantitative and two qualitative enzyme linked immunosorbent assays for H pylori IgG, used according to the manufacturers' instructions, with serum samples obtained during the endoscopy visit, were compared.
  
  
  RESULTS
  The study population had a median age of 45 years, and the prevalence of H pylori infection was 35%. With one exception, where the patient had received a course of anti-H pylori treatment between endoscopy and UBT, there was 100% concordance in the results of the two gold standard techniques. Discordant serology results were more common in patients aged > 50 years (42% of the total) than in younger patients (21%), and this was most noticeable in uninfected patients. The sensitivity of the kits was good (90-100%), but specificity was more variable (76-96%), and the rate of equivocal results was unacceptably high in some cases (0-12%). The overall accuracy of the kits ranged from 83 to 98%. Two kits in particular performed well (Pylori-Elisa II, Bio-Whitaker and Premier, Launch; qualitative) with 98% and 100% accuracy, respectively.
  
  
  CONCLUSIONS
  In a symptomatic population with a prevalence of H pylori infection of 35%, particularly in patients aged < 50 years, some but not all serology kits may be used as a highly accurate and inexpensive alternative to the gold standard techniques.
authors.affiliation: Clinical Microbiology and Public Health Laboratory, Addenbrooke's Hospital, Cambridge.
authors.forename: M H
authors.initials: MH
authors.lastname: Wilcox
authors.forename: T H
authors.initials: TH
authors.lastname: Dent
authors.forename: J O
authors.initials: JO
authors.lastname: Hunter
authors.forename: J J
authors.initials: JJ
authors.lastname: Gray
authors.forename: D F
authors.initials: DF
authors.lastname: Brown
authors.forename: D G
authors.initials: DG
authors.lastname: Wight
authors.forename: E P
authors.initials: EP
authors.lastname: Wraight
mesh_terms: D000328:Adult; D000368:Aged; D004415:Dyspepsia / Q000382:microbiology; D004797:Enzyme-Linked Immunosorbent Assay / Q000592:standards; D016481:Helicobacter Infections / Q000175:diagnosis*; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D008875:Middle Aged; D011933:Reagent Kits, Diagnostic / Q000592:standards*; D012680:Sensitivity and Specificity
chemical_list: D011933:Reagent Kits, Diagnostic