Korean J Intern Med.  2008 Sep;23(3):134-139. 10.3904/kjim.2008.23.3.134.

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

• Cho YS
• Chae HS
• Jang SN
• Kim JS
• Son HS
• Kim HK
• Kim BW
• Han SW
• Choi KY
• Lee HK
• Chang ED

• KMID: 759970
• DOI: http://doi.org/10.3904/kjim.2008.23.3.134

Abstract

BACKGROUND/AIMS: The 13C-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 13C-UBT results. METHODS: One hundred and twenty-three patients participated. The UBT was performed after ingestion of a capsule containing urea. A change in 13C-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 13C-UBT (r=0.426, p<0.001). A significant correlation was also observed between the histologically determined H. pylori density and 13C-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.

Keyword

Helicobacter pylori; Mucosal surface pH; Phenol red; Urea breath test

MeSH Terms

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/*diagnostic use
Urease/*diagnostic use