White opaque substance visualized by magnifying narrow-band imaging is associated with intragastric acid conditions

Abstract

Background and study aims The presence of white opaque substance (WOS) is an endoscopic marker of intestinal metaplasia. Considering that the nature of WOS is absorbed lipid droplets, lipase plays an important role in the lipid absorption process and is inactivated at strong acidity. WOS may only be present in a hypochlorhydria state following Helicobacter pylori infection, and, thus, may not be highly sensitive marker, especially in H. pylori- eradicated patients. We investigated the relationship between WOS and gastric acid conditions. Patients and methods A total of 501 patients were retrospectively evaluated for the presence of WOS at 2 regions of interest using magnifying narrow-band imaging. The pH level of collected gastric juice was also measured. Study end points were (1) prevalence of WOS and its relationship with gastric juice pH in 3 groups: H. pylori- uninfected , H. pylori- infected, and H. pylori -eradicated; (2) the relationship between prevalence of WOS and gastric juice pH before and after proton pump inhibitor (PPI) administration in 29 H. pylori -eradicated cases. Results Prevalence of WOS was 0 % (0 /206), 28.4 % (31/109), and 3.2 % (6/186) in the H. pylori -uninfected, H. pylori -infected, and H. pylori -eradicated groups, respectively. Mean gastric juice pH was significantly higher in WOS-positive cases than in WOS-negative cases in the H. pylori -infected and H. pylori -eradicated groups ( P < 0.0001). Mean gastric juice pH increased from 1.1 to 6.9 after PPI administration and WOS prevalence increased from 0 % (0/29) to 45 % (13/29) of cases. Conclusion The prevalence of WOS is closely associated with the neutralization of intragastric pH.

Review: Diagnosis of Helicobacter pylori infection

“…A cross-sectional study including a total of more than 76 000 patients undertaken by Eisdorfer compared to 62.6% in the lower quintile (OR: 1.22; 95% CI: 1.11-1.35, P < .01), that is, a small but significant difference. The diagnostic odds ratios (OR) for 13 C-UBT, 14 C-UBT, serology, and SAT were 153, 105, 47, and 45, respectively (a higher diagnostic OR being indicative of better test performance). The authors therefore hope that this may contribute to a wider dissemination of this test in the country; its availability is currently restricted to large cities and university centers.…”

“…Using data from 99 studies in an indirect test comparison, statistical evidence of a difference in diagnostic accuracy between these tests could be confirmed. The diagnostic odds ratios (OR) for 13 C-UBT, 14 C-UBT, serology, and SAT were 153, 105, 47, and 45, respectively (a higher diagnostic OR being indicative of better test performance). The sensitivity estimated at a specificity of 90% (median from studies across the four tests) was 94% for the 13 C-UBT, 92% for the 14 C-UBT, 84% for serology, and 83% for SAT.…”

Antacids may increase the appearance of white opaque substance in Helicobacter pylori-eradicated gastric epithelial neoplasia

“…Studies of Helicobacter pylori infection-associated intestinal metaplasia of the stomach using lipid staining and light microscopy or electron microscopy showed that the epithelium in intestinal metaplasia has ability to absorb lipid droplets 6 7 . We have more recently clarified clinical significance of WOS which signifies “absorbed lipid droplets” in intestinal metaplasia and its limitations from the perspective of intragastric acid conditions 8 9 . Interestingly, presence of WOS in intestinal metaplasia was closely associated with a state of hypochlorhydria following H. pylori infection, and WOS was not observed in intestinal metaplasia following acid recovery after H. pylori eradication 8 9 .…”

“…We have more recently clarified clinical significance of WOS which signifies “absorbed lipid droplets” in intestinal metaplasia and its limitations from the perspective of intragastric acid conditions 8 9 . Interestingly, presence of WOS in intestinal metaplasia was closely associated with a state of hypochlorhydria following H. pylori infection, and WOS was not observed in intestinal metaplasia following acid recovery after H. pylori eradication 8 9 . This is because lipase, which plays a crucial role in lipid digestion and absorption, is inactivated in strong acidity 10 .…”

“…This is because lipase, which plays a crucial role in lipid digestion and absorption, is inactivated in strong acidity 10 . However, after proton pump inhibitor (PPI) administration, WOS in intestinal metaplasia appeared dramatically in 45 % of H. pylori -eradicated cases following neutralization of gastric pH 8 9 . Whether WOS in “gastric epithelial neoplasia” is similarly affected following acid recovery after H. pylori eradication is unknown.…”