Immune Studies in IBD//


Bernstein CN, Kuenzig E, Coward SE, Nugent Z, Nasr A, El Matary W, Singh H, Kaplan GG, Benchimol EI. Increased Incidence of Inflammatory Bowel Disease after Hirschsprung Disease: A Population-based Cohort Study. Journal of Pediatrics 2021; 233: 98-104. 

To determine the frequency with which IBD is diagnosed in persons with Hirschsprung disease in population-based datasets from 3 Canadian provinces. In study I, Ontario data were used to assess the incidence of IBD in a birth cohort of children with Hirschsprung disease relative to children without Hirschsprung disease. In study II, a case-control design was used in Alberta and Manitoba to determine the frequency of previously diagnosed Hirschsprung disease in persons with IBD, compared with the frequency of Hirschsprung disease in matched controls. Validated algorithms for Hirschsprung disease and IBD were applied to each provincial health registry.

In study I, of the 716 children diagnosed with Hirschsprung disease in Ontario since 1991, 18 (2.5%) ultimately developed IBD (168.8 per 100 000 person-years), compared with 7109 of 3 377 394 children without Hirschsprung disease (0.2%, 14.2 per 100 000 person-years). The percentage of males with post-Hirschsprung disease IBD was 77.8%. The incidence rate ratio was 11.9 (95% CI, 7.5-18.8). In study II, the OR of having had Hirschsprung disease before a diagnosis of IBD compared with controls was 74.9 (95% CI, 17.1-328.7) in Alberta and 23.8 (95% CI, 4.6-123) in Manitoba. Crohn's disease was more common after Hirschsprung disease than ulcerative colitis.

We concluded that IBD can emerge in more than 2% of patients with Hirschsprung disease and, like Hirschsprung disease itself, is more common in males. IBD is much more common after a diagnosis of Hirschsprung disease than in the general population.

Witges K, Shafer LA, Zarychanski R, Abou-Setta AM, Rabbani R, Dingwall O, Bernstein CN. Ipilimumab induced enterocolitis: A systematic review and meta-analysis. Drug Safety 2020; 43, 1255–1266. 


Checkpoint inhibitor drugs including ipilimumab have been reported to induce intestinal injury. There are several aspects of checkpoint inhibitor induced colitis that are unknown. We aimed to evaluate the risk of chronic (> 6 weeks) enterocolitis following ipilimumab administration, and the likelihood that an enteritis vs colitis or enterocolitis is seen. We searched MEDLINE, EMBASE, CENTRAL, the World Health Organization International Clinical Trials Registry, and conference proceedings. We included: (1) randomized controlled trials comparing ipilimumab administration with placebo/standard care/other active chemotherapy regimens and (2) prospective observational studies. Separate meta-analyses were performed for randomized controlled trials and observational studies. Of 4760 records, we included 10 unique randomized controlled trials (n = 5814 subjects) and 34 unique prospective observational studies (n = 3699 subjects). In randomized controlled trials, the pooled relative risk of ≥ grade 3 enterocolitis or ≥ grade 3 diarrhea associated with ipilimumab was 13.31 (95% confidence interval 6.01-29.48, I2 = 0%, ten trials) and 6.72 (95% confidence interval 3.30-13.65, I2 = 63%, ten trials), respectively. In observational studies, the 3-monthly risk of developing grade 3 or higher enteritis, colitis, or enterocolitis was 4% (95% confidence interval 3-7, I2 = 77.40%, 25 studies). Randomized controlled trials and observational studies did not distinguish between acute and chronic enterocolitis. Of the included observational studies, the pooled risk of incurring small bowel involvement associated with ipilimumab was 1% (95% CI 0-4, I2 = 0%, four studies) per every 3-month time period.


Insufficient data exist to quantify or distinguish the risk of acute vs chronic enterocolitis following ipilmumab use. Because of the serious impact of chronic enterocolitis on quality of life and further cancer treatment, future trials evaluating the safety of immunotherapy should report gastrointestinal events in greater detail.