title: A rapid continuous-real-time 13C-urea breath test for the detection of Helicobacter pylori in patients after partial gastrectomy.
abstract: BACKGROUND
  Before the development of efficient medications for peptic ulcer disease many patients were treated surgically by partial gastrectomy. The pathogenetic role of Helicobacter pylori was also not known yet. Some of these patients may therefore still harbor H. pylori in their remnant stomach as a carcinogenic agent for gastric cancer. This could be even more relevant for patients who were operated for tumors in the stomach. The efficacy of the urea breath test (UBT) is not clear in this population.
  
  
  OBJECTIVE
  To study the prevalence of H. pylori and to evaluate the sensitivity and specificity of the continuous UBT (BreathID) in postgastrectomized patients in Israel. In this system, the pH of the stomach is lowered by the addition of citric acid that may be beneficial in the smaller and more alkalic stomach.
  
  
  METHODS
  We compared retrospectively the results of our continous UBT with a rapid urease test (RUT) and the histology in all our patients who underwent gastroscopy for any clinical indication, and had a history of partial gastrectomy during the years 2002 to 2010. Only patients in whom H. pylori was tested by all the 3 methods during the same day were included in the study. We identified 76 such patients older than 18 years and performed a statistical analysis of all possibly related clinical data. The 3 methods were compared with each other.
  
  
  RESULTS
  H. pylori was positive in 14/76 (18.4%) patients when histology was considered as the gold standard method. The positive predictive value of the continuous UBT and the RUT was 0.64 and 0.35, respectively. The negative predictive value was high by both the methods, 0.92 and 0.95, respectively. Weight loss was correlated with positivity for H. pylori (P=0.032) and a longer gastric stump was marginally related to H. pylori (P=0.071). There was no difference for H. pylori positivity between patients with Billroth I or Billroth II operations. Prevalence of H. pylori was not lower in patients who had partial gastrectomy several years earlier.
  
  
  CONCLUSIONS
  The prevalence of H. pylori is considerable even several years after partial gastrectomy. The BreathID is reliable to exclude H. pylori after partial gastrectomy. The positive predictive value of the UBT is not very high but better than the RUT. We suggest that all positive patients found by the breath test should be treated. Our results support the view that alternative noninvasive methods, such as the stool antigen test should be further studied and compared with the BreathID in larger populations.
authors.affiliation: Department of Gastroenterology, Assaf Harofeh Medical Center, Sackler School of Medicine, Tel-Aviv University, Zerifin, Israel.
authors.forename: Joram
authors.initials: J
authors.lastname: Wardi
authors.forename: Tamar
authors.initials: T
authors.lastname: Shalev
authors.forename: Orit
authors.initials: O
authors.lastname: Shevah
authors.forename: Mona
authors.initials: M
authors.lastname: Boaz
authors.forename: Yona
authors.initials: Y
authors.lastname: Avni
authors.forename: Haim
authors.initials: H
authors.lastname: Shirin
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001944:Breath Tests / Q000379:methods; D019343:Citric Acid / Q000737:chemistry; D005260:Female; D005743:Gastrectomy; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007557:Israel; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015995:Prevalence; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013270:Stomach / Q000737:chemistry / Q000382:microbiology / Q000601:surgery; D013274:Stomach Neoplasms / Q000382:microbiology / Q000601:surgery; D013997:Time Factors; D014508:Urea / Q000032:analysis; D014510:Urease / Q000032:analysis
chemical_list: D019343:Citric Acid; D014508:Urea; D014510:Urease