Comparison of the 13C-urea breath test and the endoscopic phenol red mucosal pH test in the quantification of Helicobacter pylori infection loading.

Abstract

BACKGROUND/AIMS:

The (13)C-urea breath test (UBT) is a semiquantitative test for measuring Helicobacter pylori infection loading. H. pylori produces ammonia, which elevates the pH of the gastric mucosa and is detectable via endoscopy using a phenol red indicator. We evaluated whether this test could be used to diagnose H. pylori infection and whether phenol red staining was correlated with (13)C-UBT results.

METHODS:

One hundred and twenty-three patients participated. The UBT was performed after ingestion of a capsule containing urea. A change in (13)C-UBT >2 ppt was selected as the cutoff value for diagnosing infection. After spraying evenly with a 0.1% phenol red solution, the pH of the gastric mucosal surface was measured using an antimony electrode through the biopsy channel.

RESULTS:

The pH of stained mucosa (6.9+/-0.4) was significantly higher than that of unstained mucosa (1.9+/-0.8; p<0.001), and the H. pylori detection rate confirmed via histology was higher in stained versus unstained mucosa (p<0.01). Extensive mucosal staining resulted in a higher detection rate (p<0.001). The UBT produced results were very similar to those obtained via histological detection in stained mucosa (p<0.001). The extent of staining, expressed as a staining score, was positively correlated with the change in (13)C-UBT (r=0.426, p<0.001). A significant correlation was also observed between the histologically determined H. pylori density and (13)C-UBT results (r=0.674, p<0.001).

CONCLUSIONS:

H. pylori infection elevates gastric mucosal surface pH, and endoscopic phenol red staining may be an alternative method for the diagnosis of H. pylori infection.

• Authors: Young-Seok Cho, Hiun-Suk Chae, Se Na Jang, Jin-Soo Kim, Hye Suk Son, Hyung-Keun Kim, Byung-Wook Kim, Sok-Won Han, Kyu-Yong Choi, Hae Kyung Lee, Eun Deok Chang
• Journal: The Korean journal of internal medicine (Korean J Intern Med) Vol. 23 Issue 3 Pg. 134-9 (Sep 2008) ISSN: 1226-3303 [Print] Korea (South)
• PMID: 18787366 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Urease
• Phenolsulfonphthalein

Topics

• Adult
• Aged
• Breath Tests
• Clinical Enzyme Tests
• Endoscopy, Gastrointestinal
• Esophageal pH Monitoring
• Female
• Gastric Mucosa (pathology)
• Helicobacter Infections (diagnosis)
• Helicobacter pylori (isolation & purification)
• Humans
• Male
• Middle Aged
• Phenolsulfonphthalein
• Urease