Vonoprazan-Associated Gastric Mucosal Redness in Non-Helicobacter pylori-Infected and Helicobacter pylori-Eradicated Stomach

Vonoprazan-associated gastric mucosal redness is rare, and its endoscopic and pathological features remain poorly described. We report 4 cases of vonoprazan-associated gastric mucosal redness, that is, 2 cases each in non-<i>Helicobacter pylori</i>-infected and -eradicated stomach. In all cases, esophagogastroduodenoscopy demonstrated spotty and linear redness newly appearing in the greater curvature of the gastric body after initiation of vonoprazan but disappearing after its discontinuation. A tissue biopsy taken from the gastric mucosa with redness revealed various pathological findings and included inflammatory cell infiltration, parietal cell protrusions, oxyntic gland dilatations, congestion, focal hemorrhage with congestion beneath the basement membrane, and vacuolar degeneration of parietal cells. To our knowledge, this is the second report describing the endoscopic and pathological features of vonoprazan-associated gastric mucosal redness.

Vitamin D Is Necessary for Murine Gastric Epithelial Homeostasis

Unlike other organs, the importance of VD in a normal stomach is unknown. This study focuses on understanding the physiological role of vitamin D in gastric epithelial homeostasis. C57BL/6J mice were divided into three groups that were either fed a standard diet and kept in normal light/dark cycles (SDL), fed a standard diet but kept in the dark (SDD) or fed a vitamin D-deficient diet and kept in the dark (VDD). After 3 months, sera were collected to measure vitamin D levels by LC-MS/MS, gastric tissues were collected for immunohistochemical and gene expression analyses and gastric contents were collected to measure acid levels. The VDD group showed a significant decrease in the acid-secreting parietal cell-specific genes Atp4a and Atp4b when compared with the controls. This reduction was associated with an increased expression of an antral gastrin hormone. VDD gastric tissues also showed a high proliferation rate compared with SDL and SDD using an anti-BrdU antibody. This study indicates the requirement for normal vitamin D levels for proper parietal cell functions.