Validation of endoscopic 13C-urea breath test with nondispersive infrared spectrometric analysis in the management of Helicobacter pylori infection.

Background/aims: 13C-EUBT (endoscopic 13C-urea breath test), that combines the conventional urea breath test with endoscopy, provides excellent accuracy for detection of H. pylori. Recently, a simpler, less expensive and isotope-selected nondispersive infrared spectrometer has been developed for the urea breath test. We validated the diagnostic performance of 13C-EUBT using nondispersive infrared spectrometer in the management of H. pylori infection.

Methodology: EUBT was performed in 232 patients by first collecting a baseline breath sample followed by upper gastrointestinal endoscopy. A 20-mL aliquot of 13C-urea solution was sprayed over the entire stomach under endoscopic guidance. Breath samples taken 0 and 20 minutes after spraying were analyzed using nondispersive infrared spectrometer. H. pylori infection was assessed by rapid urease test and histology. The cutoff level was determined by a receiver-operating characteristic curve analysis. Forty-four samples were also analyzed by the conventional isotope ratio mass spectrometer to compare results from both analyzers. We also applied the nondispersive infrared spectrometer-based EUBT to evaluate the efficacy of eradication therapy.

Results: Employing 2.4 per mL as the best cutoff value, the EUBT yielded an excellent diagnostic accuracy, with a sensitivity of 99% and specificity of 99%. The sensitivity and specificity of the test for assessing eradication therapy were 94% (16/17) and 100% (57/57), respectively. There was a high linear correlation between nondispersive infrared spectrometer and isotope ratio mass spectrometer (r = 0.998, p < 0.0001).

Conclusions: 13C-EUBT using nondispersive infrared spectrometer is a highly accurate and rapid method for the assessment of H. pylori eradication as well as for detecting H. pylori infection. We believe that nondispersive infrared spectrometer gives more rapid and less expensive method for the management of H. pylori infection with the EUBT.