Published online Aug 28, 2023. doi: 10.3748/wjg.v29.i32.4912
Peer-review started: May 15, 2023
First decision: July 10, 2023
Revised: July 18, 2023
Accepted: August 1, 2023
Article in press: August 1, 2023
Published online: August 28, 2023
Processing time: 101 Days and 22.5 Hours
Interleukin-17 (IL-17) inhibitors are known to cause exacerbation or new onset of inflammatory bowel disease upon administration. However, few reports have described characteristic endoscopic and histopathologic findings, and no small intestinal lesions have been reported so far.
A woman in her 60s with psoriasis was administered ixekizumab (IXE), an anti-IL-17A antibody, for the treatment of psoriasis. Twenty months after commencing treatment, the patient visited our hospital because of persistent diarrhea. Blood tests performed at the time of the visit revealed severe inflammation, and colonoscopy revealed multiple round ulcers throughout the colon. A tissue biopsy of the ulcer revealed infiltration of inflammatory cells and granuloma-like findings in the submucosal layer. Capsule endoscopy revealed multiple jejunal erosions. After the withdrawal of IXE, the symptoms gradually improved, and ulcer reduction and scarring of the colon were endoscopically confirmed.
To the best of our knowledge, 17 reports have documented IL-17 inhibitor-induced entero-colitis with endoscopic images, endoscopic findings, and pathological characteristics, including the present case. Nine of these cases showed diffuse loss of vascular pattern, coarse mucosa/ulcer formation in the left colon, and endoscopic findings similar to those of ulcerative colitis. In the remaining eight cases, discontinuous erosions and ulcerations from the terminal ileum to the rectum were seen, with endoscopic findings similar to those of Crohn’s disease. In this case, the findings were confirmed by capsule endoscopy, which has not been previously reported.
Core Tip: While Interleukin-17 (IL-17) inhibitors are effectively used in the treatment of psoriasis, psoriatic arthritis, and ankylosing spondylitis, they are ineffective in patients with Crohn’s disease (CD) and can worsen their condition. To the best of our knowledge, we present capsule endoscopic images of IL-17 inhibitor-induced entero-colitis for the first time, suggesting that IL-17-induced inflammatory lesions may be distributed in the proximal small bowel, unlike CD lesions. We also compared the endoscopic and pathological features of IL-17 inhibitor-induced entero-colitis with those previously reported.