2024 Volume 66 Issue 3 Pages 266-272
Immune checkpoint inhibitors (ICIs) have widely been used in immunotherapy to target programmed cell death-1 (PD-1), PD ligand 1 (PD-L1), as well as cytotoxic T-lymphocyte associated antigen 4 (CTLA-4). ICIs inhibit the signaling from receptors and ligands, thereby helping boost the bodyʼs immune response against cancer cells. Simultaneously, activated T-lymphocytes can recognize and attack the bodyʼs healthy organs, leading to immune-related adverse events (irAEs). Colitis often occurs as an irAE, while gastritis associated with ICIs is infrequent. In the present study, we retrospectively analyzed five patients (one man and four women) diagnosed with gastritis associated with ICIs (irAE gastritis), at Okayama University Hospital between January 2014 and December 2022, to reveal the clinical features of the disease. The primary diagnosis was malignant melanoma in all cases; the average age of the patients was 68.5 years (57-79 years). The ICIs administered at the onset of irAE gastritis were nivolumab and ipilimumab in two patients and nivolumab, ipilimumab, and pembrolizumab, each in one patient. The chief complaints were anorexia (n = 3), nausea (n = 2), vomiting (n = 2), diarrhea (n = 2), abdominal distension (n = 1), and abdominal pain (n = 1). CT showed thickening of the gastric antrum in one patient, while the remaining four patients had no notable findings in the upper gastrointestinal tract. On EGD, irAE gastritis showed rough mucosa (n = 4), white exudates (n = 4), redness (n = 4), friable mucosa with spontaneous bleeding (n = 4), edematous mucosa (n = 1), and small ulcers (n = 1). Magnifying observation of the gastric lesions was performed in four cases and revealed the disappearance of ductal structures in all cases. Subjective symptoms improved in all patients after the administration of steroids.
