CLINICAL FEATURES OF GASTROPATHY ASSOCIATED WITH PROTON PUMP INHIBITORS (GAP)

Abstract

Gastric mucosal changes associated with proton pump inhibitors (PPIs), including potassium-competitive acid blockers (P-CABs), were first described by Haruma as gastropathy associated with PPI (GAP). GAP involves the development and enlargement of fundic gland polyps and foveolar-hyperplastic polyps, multiple white and flat elevated lesions (Haruma-Kawaguchi lesions), cracked mucosa, cobblestone-like mucosa, and black spots. New gastric lesions such as white spots, diffuse redness, and web-like mucus have also been noted with the introduction of P-CABs in Japan in 2015,.

The mechanisms of GAP are unknown; however, hypergastrinemia secondary to PPI, P-CABs, or other factors may be involved. Additionally, an acid-free environment in the stomach, caused by the strong inhibitory effect of P-CAB on acid secretion, is a common finding in autoimmune gastritis. These occurrences must be noted, and the detailed pathogenesis and clinical importances of these cases must be examined, as the frequency of GAP is expected to increase in the future.