title: A novel one-step Helicobacter pylori saliva antigen test.
abstract: BACKGROUND
  A rapid, reliable, and sufficiently accurate test for diagnosing Helicobacter pylori infection is required for screening dyspeptic patients before a referral for endoscopy. The purpose of this article is two-fold: first, to evaluate the accuracy of a one-step H. pylori saliva antigen (HPS) test; and second, to compare noninvasive and invasive H. pylori tests in Taiwanese population.
  
  
  METHODS
  A total of 104 consecutive dyspeptic patients admitted for gastroenterology into the outpatient department underwent a one-step HPS test, rapid urease test, histology, and (13)C-urea breath test (13)C-UBT (proto C-13 urea kit). The accuracy of the HPS test was compared with a gold standard defined by at least two positive H. pylori test results from three H. pylori tests (histology, rapid urease test, and (13)C-UBT).
  
  
  RESULTS
  The 104 patients eligible for analysis (mean age: 58 years, range 22-87 years), 21 (20%) were gold standard positive. Among them, the positive of the one-step H. pylori saliva Ag test, rapid urease test, (13)C-UBT, histology were (52; 50%), (17; 16%), (27; 25%) and (22; 21%) respectively. The sensitivity and specificity of the HPS tests, rapid urease test, (13)C-UBTs, and histology were 71.43% and 55.42%, 76.19% and 98.80%, 100% and 92.77%, and 85.71% and 95.18%, respectively, relative to the gold standard. The one-step HPS test exhibited a sensitivity of 71.43%, nearly equivalent to that of the rapid urea test.
  
  
  CONCLUSIONS
  The one-step HPS test exhibited a high sensitivity and low specificity compared with the other tests, indicating that it is not sufficiently accurate for use in a clinical setting for diagnosing H. pylori infection. However, the test is simple to use (requiring only a saliva sample), inexpensive, and noninvasive in its application, and thus appealing for use in population-based prevalence surveys of the epidemiology of H. pylori infection.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Cheng-Hsin General Hospital, Taipei, Taiwan, ROC; Division of Gastroenterology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC.
authors.forename: Bi-Ling
authors.initials: BL
authors.lastname: Yang
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Cheng-Hsin General Hospital, Taipei, Taiwan, ROC. Electronic address: franklinn2800@gmail.com.
authors.forename: Chun
authors.initials: C
authors.lastname: Yeh
authors.affiliation: Department of Pathology, Cheng-Hsin General Hospital, Taipei, Taiwan, ROC.
authors.forename: Wei-Gang
authors.initials: WG
authors.lastname: Kwong
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Cheng-Hsin General Hospital, Taipei, Taiwan, ROC; Division of Gastroenterology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC.
authors.forename: Shou-Dong
authors.initials: SD
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000942:Antigens, Bacterial / Q000032:analysis*; D004415:Dyspepsia / Q000175:diagnosis; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis*; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012463:Saliva / Q000276:immunology*; D055815:Young Adult
chemical_list: D000942:Antigens, Bacterial
keywords: Helicobacter pylori; one-step H. pylori saliva antigen test