Clinical Characteristics and Outcomes of Gastritis Associated With Immune Checkpoint Inhibitors: Scoping Review

Among immune-related adverse events associated with immune checkpoint inhibitors, immune-mediated gastritis (IMG) has been rarely described in the literature and has not yet been well characterized. This scoping review aimed to characterize IMG in terms of precipitating agents, clinical presentations, and prognosis. After the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews, we searched MEDLINE and EMBASE for all peer-reviewed articles using keywords including "gastritis," "immune checkpoint inhibitor," and "immune-related adverse event" from their inception to December 28, 2021. Twenty-two articles, including 5 observational studies and 17 case reports and case series, were included. Nivolumab, pembrolizumab, and combination therapy with those and cytotoxic T-lymphocyte-associated antigen-4 inhibitor (ipilimumab) were commonly used in those with IMG. 59.8% had epigastric pain, and 50% had erosive gastritis. 87.5% had Common Terminology Criteria for Adverse Events (CTCAE) grade 3 gastritis, and 91.2% received corticosteroids. Recurrence was noted in 16.7%, and only 1 expiration was noted. 4.3% had positive helicobacter pylori and cytomegalovirus from the gastric specimen. Similar to immune-related colitis, patients with IMG may have a favorable prognosis with a better response to immune checkpoint inhibitors if treated appropriately. The diagnosis of IMG is made by exclusion, and a thorough workup is necessary to rule out concurrent helicobacter pylori and cytomegalovirus involvement. Further studies are critical for a better understanding of this complication.