University of Minnesota Medical Center Minneapolis, MN, United States
Award: Presidential Poster Award
Raiya Sarwar, MD1, Aasma Shaukat, MD, MPH2 1University of Minnesota Medical Center, Minneapolis, MN; 2University of Minnesota, Minneapolis, MN
Introduction: Immune checkpoint inhibitors (ICIs) have made a remarkable breakthrough in the treatment of malignancies, however, there are several immune-related adverse events (irAEs) including immune-mediated colitis (IMC) and enteritis which recently has become an area of interest in gastroenterology due to the complexity of management.
Case Description/Methods: A 73-year-old man with a history of stage IV non-small cell lung carcinoma who underwent five cycles of pembrolizumab, admitted to hospital with acute onset hematochezia. Upon presentation, his vitals were stable with normocytic anemia (Hgb from 10.8 gm/dL to 7.8 gm/dL) and thrombocytopenia (platelets 76,000 / µL). The patient underwent colonoscopy showing diffuse mucosal inflammation and ulceration; pathology was consistent with diffuse active colitis without features of chronicity favoring immune-mediated colitis. The patient was started on steroid therapy and vedolizumab induction. Unfortunately, he received another cycle of pembrolizumab infusion at an outside facility two weeks after the vedolizumab, missed the 2nd-week induction dose, and presented with a recurrent episode of hematochezia two weeks later. At this point, he received vedolizumab infusion as re-induction along with continuation of steroid tapering. He had improvement in his hematochezia but clinical course was complicated with worsening diarrhea after finishing induction and steroid taper, considered as refractory colitis, and switched to infliximab. Due to persistent diarrhea, he underwent a repeat colonoscopy showing diffusely inflamed colonic mucosa with large ulcers, extending from the rectum to ascending colon, pathology consistent with diffuse neutrophilic colitis with ulceration and elements of chronicity. Cytomegalovirus inclusions were identified upon immunostaining along with positive blood CMV PCR of 12000 IU/mL. Clinical diagnosis of CMV colitis on the background of immune checkpoint inhibitor colitis was made with the initiation of ganciclovir; while infliximab induction was continued.
Discussion: Incidence of immune-mediated colitis ranges from 1%-25% depending on the type of ICI and combination therapy, typically occurs 5-10 weeks after the 2nd or 3rd dose of treatment. Given the paucity of identical cases upon literature review, the key point, in this case, was the diagnosis of CMV colitis on the background of IMC and treatment therapy for both with goal of negative viral load and resolution of symptoms. The treatment goal is a potential area for future research.
Figure: Colonoscopy showing diffuse inflammation and ulcerations, pathology showing acute and chronic inflammation, IHC positive for CMV
Disclosures: Raiya Sarwar indicated no relevant financial relationships. Aasma Shaukat indicated no relevant financial relationships.
Raiya Sarwar, MD1, Aasma Shaukat, MD, MPH2. P1216 - An Interesting Case of Immune Mediated and Infectious Colitis, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.
