title: Comparison of three stool antigen assays with the 13C- urea breath test for the primary diagnosis of Helicobacter pylori infection and monitoring treatment outcome.
abstract: BACKGROUND
  The urea breath test (UBT) is the gold-standard non-invasive test for the detection of Helicobacter pylori infection, however, the lack of availability of the UBT due to the high cost of the test, and in particular the need for expensive analytical instrumentation, limits the usefulness of this method. Stool antigen assays may offer an alternative non-invasive method for the diagnosis of infection.
  
  
  OBJECTIVE
  To compare the accuracy of three stool antigen assays (HpSA, IDEIA HpStAR, and ImmunoCard STAT) against the UBT for the primary diagnosis of H. pylori infection and for monitoring treatment outcome.
  
  
  METHODS
  A total of 102 patients attending two gastroenterology day-case clinics for the investigation of dyspepsia were included. Each patient provided breath and stool samples for analysis. Patients who tested positive for H. pylori by the validated UBT were prescribed triple therapy and invited to return for repeat breath and stool sample analysis 6 weeks post-treatment.
  
  
  RESULTS
  Of the 102 patients tested, 48 were diagnosed with H. pylori infection by the UBT. The HpSA assay interpreted 38 of these as positive (79% sensitive). Of the 54 UBT-negative patients the HpSA assay interpreted all 54 as negative (100% specific). The IDEIA HpStAR assay correctly identified 44 patients as positive (92% sensitive) and 50 as negative (92.5% specific). The ImmunoCard STAT assay interpreted 38 patients as positive (79% sensitive) and 52 as negative (96.3% specific).
  
  
  CONCLUSIONS
  The findings indicate that the IDEIA HpStAR stool antigen kit is the most accurate assay of the three assays evaluated, and possibly represents a viable alternative to the UBT for the primary diagnosis of H. pylori infection and for monitoring treatment outcome.
authors.affiliation: Cork University Hospital, Cork, Ireland. hootonc@shb.ie
authors.forename: Carmel
authors.initials: C
authors.lastname: Hooton
authors.forename: John
authors.initials: J
authors.lastname: Keohane
authors.forename: Jim
authors.initials: J
authors.lastname: Clair
authors.forename: Mohammad
authors.initials: M
authors.lastname: Azam
authors.forename: Seamus
authors.initials: S
authors.lastname: O'Mahony
authors.forename: Orla
authors.initials: O
authors.lastname: Crosbie
authors.forename: Brigid
authors.initials: B
authors.lastname: Lucey
mesh_terms: D000328:Adult; D000942:Antigens, Bacterial / Q000032:analysis*; D001944:Breath Tests; D002247:Carbon Isotopes; D004415:Dyspepsia / Q000209:etiology; D005243:Feces / Q000382:microbiology*; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis*; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D014508:Urea
chemical_list: D000942:Antigens, Bacterial; D002247:Carbon Isotopes; D014508:Urea