ABSTRACT
OBJECTIVE: The mechanism of false negative urea breath tests (UBTs) results among proton pump inhibitor (PPI) users is unknown. We studied the time course of PPI-associated negative UBT, the relation to Helicobacter pylori density, and whether gastric acidification would prevent false negative UBT results. METHOD: In the UBT experiment, H. pylori-infected volunteers received omeprazole 20 mg b.i.d. for 13.5 days. UBTs with citric acid were done before, after 6.5 days of PPI, and 1, 2, 4, 7, and 14 days after therapy. In the culture and histology experiment, after a wash-out of >5 months, nine of the original subjects were rechallenged with omeprazole for 6.5 days. Antral and corpus biopsies for histology and culture were done before and 1 day after PPI administration. RESULTS: Thirty subjects (mean age 42 yr) were enrolled. UBTs were significantly reduced on day 6.5 (p = 0.031); 10 subjects (33%) developed transient negative UBTs. The UBT recovered in all but one subject by the fourth day post-PPI and in all subjects by day 14. In the culture and histology experiment, upon PPI rechallenge, three of nine subjects (33%) had negative UBTs. H. pylori density, whether measured by culture or histology, decreased with PPI therapy; antral biopsies became histologically negative in five subjects and corpus biopsies in three subjects. CONCLUSION: PPI-induced negative UBT results were related to the anti-H. pylori effect of the PPI. Acidification of the stomach did not prevent false negative UBT results. Three days is likely the minimum delay from stopping PPI until one should perform a test for active infection. A delay of 14 days is preferred.
Subject(s)
Anti-Ulcer Agents/therapeutic use , Helicobacter Infections/diagnosis , Helicobacter Infections/drug therapy , Helicobacter pylori/isolation & purification , Omeprazole/therapeutic use , Urea , Adult , Breath Tests/methods , Carbon Radioisotopes , False Negative Reactions , Female , Helicobacter pylori/drug effects , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Proton Pump Inhibitors , Statistics, Nonparametric , Stomach/microbiology , Stomach/pathology , Time FactorsABSTRACT
The 13C-urea breath test provides accurate, noninvasive diagnosis of active Helicobacter pylori infection and can document posttherapy cure. This study evaluated point-of-care testing with onsite sample analysis with the use of a desktop infrared spectrophotometer. Ambulatory patients (N=320) underwent 13C-urea breath testing, and breath samples were analyzed immediately by clinic staff with no prior breath testing experience. Duplicate samples were sent to a reference laboratory, and the results of both methods were compared. Point-of-care testing was simple, with an overall agreement of 99.1%. Accurate near-patient 13C-urea breath testing is now practical in the primary care setting even when done by inexperienced personnel.
