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, 13 (5), 506-514

Effect of Citric Acid on Accuracy of 13 C-Urea Breath Test After Helicobacter pylori Eradication Therapy in a Region With a High Prevalence of Atrophic Gastritis


Effect of Citric Acid on Accuracy of 13 C-Urea Breath Test After Helicobacter pylori Eradication Therapy in a Region With a High Prevalence of Atrophic Gastritis

Yong Hwan Kwon et al. Gut Liver.


Background/aims: The validity of 13C-urea breath test (13C-UBT) for Helicobacter pylori detection is influenced by atrophic gastritis. The aim of this study was to evaluate the effect of citric acid on the accuracy of 13C-Urea breath test after H. pylori eradication therapy in a region where atrophic gastritis is common.

Methods: In this prospective study, H. pylori-positive patients received 13C-UBT after H. pylori eradication regimen. They were classified into citric acid group and control group. To determine diagnostic accuracy of 13C-UBT, patients were offered invasive methods.

Results: A total of 1,207 who successfully took H. pylori-eradication regimen received UBT. They were assigned into the citric acid group (n=562) and the control group (n=645). The mean 13C-UBT value of the citric acid group was 10.3±26.4‰, which was significantly (p<0.001) higher than that of that control group (5.1‰±12.6‰). Of these patients 122 patients were evaluated by endoscopic biopsy methods. Based on invasive tests, the accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 13C-UBT for the citric acid group were 83.3%, 91.7%, 81.3%, 55.0%, and 97.5%, respectively. Those of the control group were 87.7%, 90.9%, 88.2%, 62.5%, and 97.8%, respectively. They were not significantly different between the two groups. Although the presence of gastric atrophy and intestinal metaplasia (IM) decreased the accuracy, the decrease was not significant.

Conclusions: In a country with high prevalence of atrophic gastritis or IM, false positivity remained common despite the use of citric acid in 13C-UBT.

Keywords: Diagnosis; Gastritis; Helicobacter pylori; atrophic.

Conflict of interest statement


No potential conflict of interest relevant to this article was reported.


Fig. 1
Fig. 1
Flowchart showing 13C-UBT compared to endoscopic biopsy-based methods for evaluating H. pylori status after eradication. 13C-UBT, 13C-urea breath test; H. pylori, Helicobacter pylori.
Fig. 2
Fig. 2
Distribution of 13C-UBT values after H. pylori eradication between the citric acid group and the control group. 13C-UBT values showed a significant difference between the two groups. SD was greater in the citric acid group than in the control group (26.2‰ vs 6.7‰). Data are presented as the mean±SD. 13C-UBT, 13C-urea breath test; H. pylori, Helicobacter pylori.
Fig. 3
Fig. 3
Flowchart showing diagnostic accuracy of 13C urea breath test (13C-UBT) results compared with endoscopic biopsy (Bx) results. Values were calculated for a UBT cutoff value of 2.5‰.

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