Non-invasive detection of Helicobacter pylori in cystic fibrosis--the fecal test vs. the urea breath test.

OBJECTIVES Only recently it has been proven that cystic fibrosis (CF) patients have the same prevalence of Helicobacter pylori (HP infection) as the general population, as well as the same spectrum of changes caused by this pathogen. The aim of this study was to assess the reliability of the two most popular noninvasive tests--the urea breath test (UBT) and the fecal test (FT) in diagnosing HP infection in CF patients. PATIENTS AND METHODS The study was conducted on 79 CF patients and 49 healthy subjects (HS). The presence of HP infection was evaluated using the 13C isotope-labeled urea breath test and the fecal test (ELISA). RESULTS Fifteen (19.0%) CF patients and eight (16.3%) HS were found to be HP positive using the UBT. The HP stool antigen was detected in twelve (15.2%) CF patients and seven (14.3%) HS. Discordant results for the two tests were obtained in 9 out of 18 (50.0%) CF patients and 3 out of 9 (33.3%) HS. Although the differences were not statistically significant, the risk of potentially false negative and false positive results in CF subjects seems to be high. Similarly, no statistical differences in the basic clinical parameters were documented between the CF subgroups with concordant and divergent HP results. CONCLUSIONS Since there is convincing evidence of divergent UBT and FT results in the CF patients, we suggest that UBT is kept as the standard method for HP detection in this population, at least until obtaining reliable and valid results allows for a change in such an approach.