S2926 Isolated Gastritis Secondary to Immune Checkpoint Inhibitors Complicated With Superimposed CMV Infection

Abstract

INTRODUCTION: This case highlights the clinical manifestations and management of a patient with gastritis that occurred after nivolumab and was complicated by superimposed cytomegalovirus (CMV) infection. CASE DESCRIPTION/METHODS: A 55-year-old male with metastatic renal cell carcinoma on nivolumab, was seen in consultation for epigastric pain, hematemesis, melena, weight loss, nausea, vomiting and food intolerance. He denied diarrhea or hematochezia. Physical exam was notable for ill appearance and epigastric tenderness. Computed tomography showed diffuse gastric wall thickening. EGD revealed diffuse severely erythematous, friable mucosa with mucosal sloughing in the entire examined stomach. Also, a group of nummular lesions were seen in the body (Figure 1). The esophagus and duodenum were normal. Gastric biopsy showed infiltration of the lamina propria with inflammatory cells and erosive mucosa, suggestive of immune checkpoint inhibitor-related gastritis. Helicobactor pylori and CMV immunostain were negative. Nivolumab was discontinued. Prednisone 140 mg and pantoprazole 40 mg oral daily were started; a dose of infliximab 5 mg/kg was administered. His symptoms initially improved but recurred within 3 weeks. A repeat EGD showed diffuse severe inflammation characterized by adherent blood, erosions, erythema, friability, granularity and confluent ulcerations in the entire stomach (Figure 2). Biopsies were notable for severe ulceration and granulation with CMV cytopathic changes, suggestive of superimposed CMV gastritis. Steroids were tapered and intravenous ganciclovir was started, resulting in resolution of hematemesisand melena and partial improvement of other symptoms. EGD was repeated and showed diffuse moderately erythematous, granular and friable mucosa with nodularity and contact oozing in entire stomach (Figure 3). Biopsies showed ulcerative gastric mucosa with dense organized granulation tissue and reactive changes. CMV immunostain was negative. Symptoms gradually improved and at 2 months follow up patient reported near complete resolution of all symptoms. DISCUSSION: Gastritis is a rare complication of nivolumab treatment. The mainstay of treatment is discontinuing nivolumab. Steroids and infliximab have been used for ICI-related colitis. However, data regarding their efficacy in patients with ICI-related gastritis is sparse. Superimposed CMV made the management of this case more challenging. Further studies are needed to better characterize the natural history and outcome of ICI-related gastritis.Figure 1Figure 2Figure 3