The histological spectrum of ARB‐induced gastritis

AIMS: Olmesartan, an angiotensin receptor blocker (ARB) used for hypertension management, is known to cause a sprue‐like enteropathy in a subset of patients. Rare cases of gastritis occurring with ARB use have also been reported, but the histological features of ARB‐induced gastritis and the response to drug cessation have not been examined in a dedicated case‐series. METHODS AND RESULTS: Cases of suspected ARB‐induced gastritis were identified from the pathology archives of four institutions. Haematoxylin and eosin (H&E) slides from gastric biopsies were reviewed. Fifteen patients (14 female, one male) were identified. The most common presenting symptoms were diarrhoea (10) and weight loss (six). Gastric biopsies commonly showed a full‐thickness active chronic gastritis with surface epithelial injury involving the antrum and body. Glandular atrophy, intra‐epithelial lymphocytosis and/or subepithelial collagen thickening were also present in some cases. Duodenal involvement, including villous atrophy, intra‐epithelial lymphocytosis and/or collagenous sprue, was identified in 11 of 13 cases with concurrent duodenal biopsies. Following drug cessation, symptomatic improvement occurred in all 11 cases for which follow‐up data were available. Histological resolution occurred in five of eight cases with follow‐up gastric biopsies, with improvement seen in the remaining three biopsies. CONCLUSION: ARB‐induced gastritis typically presents as active chronic gastritis, frequently with associated surface epithelial injury. Glandular atrophy, intra‐epithelial lymphocytosis and/or subepithelial collagen thickening may also be present. These gastric changes can be seen without associated duodenal injury in rare cases, and they should alert the pathologist to the possibility of ARB‐induced injury. Drug cessation results in marked symptomatic and histological improvement.