title: The CLO test is unreliable in diagnosing H. pylori infection in post-surgical stomach; is there any role of H. pylori in peptic ulcer recurrence?
abstract: OBJECTIVE
  To evaluate the validity of the CLO test in detecting Helicobacter pylori in patients with gastric operation and to investigate the relationship of H. pylori with peptic ulcer recurrence in these patients.
  
  
  METHODS
  In this prospective study, 110 consecutive patients, the majority of whom had undergone gastric operation for benign disease (n = 102), were included. Eighty patients (62 males), aged 38-87 years, had had a gastrectomy (10 Billroth I, 70 Billroth II), and 30 patients (27 males), aged 36-73 years, had had a vagotomy (13 vagotomy plus gastroenterostomy, 17 vagotomy plus pyloroplasty). H. pylori was sought on multiple biopsy specimens, using CLO test and histology (modified Giemsa stain). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the CLO test were estimated using histology as 'gold standard'.
  
  
  RESULTS
  Overall, 21 gastrectomy patients (26%) were H. pylori-positive by CLO and 25 (31 %) were H. pylori-positive by histology. The estimated sensitivity, specificity, PPV and NPV of the CLO test, using histology as 'gold standard', were 68%, 91%, 77% and 86%, respectively. The CLO test was positive in 67% of vagotomy patients (20 of 30), while 50% (15 of 30) were H. pylori-positive by histology. The estimated sensitivity, specificity, PPV and NPV of the CLO test were 87%, 53%, 65% and 80%, respectively. H. pylori prevalence by histology was 50% in patients with vagotomy and 31% in those with gastrectomy (P = 0.0787). Recurrent ulcers were observed in 8/30 patients (27%) after vagotomy and in 10/72 patients (14%) after gastrectomy. Recurrent ulcer was documented in 6/15 H. pylori-positive patients with vagotomy (40%), and in one of 25 H. pylori-positive patients with gastrectomy (4%). This difference was significant (Fisher's exact test, P = 0.007, relative risk 5.091, 95% CI 0.819-31.64).
  
  
  CONCLUSIONS
  The CLO test seems to be unreliable in diagnosing H. pylori in post-surgical stomach. The H. pylori prevalence is higher, although not significantly, in vagotomized patients compared with gastrectomized patients, and in this group is closely related to the presence of recurrent ulcer. So, at least in this group of patients, it is strongly recommended to look for and eradicate H. pylori.
authors.affiliation: Department of Pathophysiology, University of Athens Medical School, Laiko General Hospital, Greece. aarchim@cc.uoa.gr
authors.forename: A
authors.initials: A
authors.lastname: Archimandritis
authors.forename: P
authors.initials: P
authors.lastname: Apostolopoulos
authors.forename: S
authors.initials: S
authors.lastname: Sougioultzis
authors.forename: I
authors.initials: I
authors.lastname: Delladetsima
authors.forename: P
authors.initials: P
authors.lastname: Davaris
authors.forename: M
authors.initials: M
authors.lastname: Tzivras
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005743:Gastrectomy; D016481:Helicobacter Infections / Q000175:diagnosis*; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D008875:Middle Aged; D010437:Peptic Ulcer / Q000382:microbiology* / Q000517:prevention & control* / Q000601:surgery; D011184:Postoperative Period; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012008:Recurrence; D012680:Sensitivity and Specificity; D014510:Urease / Q000032:analysis*; D014628:Vagotomy
chemical_list: D014510:Urease