The following is a summary of “Development of Inflammatory Bowel Disease in Children With Juvenile Idiopathic Arthritis Treated With Biologics,” published in the February 2023 issue of Gastroenterology and Nutrition by Broekaert, et al.

For a study, researchers sought to discover risk factors for developing inflammatory bowel disease (IBD) in juvenile idiopathic arthritis (JIA) patients and explain the distinctive characteristics of IBD in these patients.

A retrospective analysis was done on data from the German Biologika in der Kinderrheumatologie registry, collected between 2001 and 2021.

About 28 out of 5,009 JIA patients had proven IBD before the age of 18: 23 (82.1%) had Crohn’s disease (CD), 4 (14.3%) had ulcerative colitis (UC), and 1 (3.6%) had IBD-unclassified (IBD-U). The incident rate of IBD during 20 years of observation was 0.56% (0.46% for CD, 0.08% for UC, and 0.02% for IBD-U), 20.3% of those with IBD were HLA-B27 positive, 25% had enthesitis-related arthritis, and 14.3% had psoriatic arthritis. In the 90 days preceding the diagnosis of IBD, 82.1% (n = 23) of patients received treatment with etanercept (ETA), 39.3% (n = 11) of non-steroidal anti-inflammatory medicines, 17.9% (n = 5) of systemic corticosteroids, 8 (28.6%) of methotrexate (MTX), 14.3% (n = 4) of sulfasalazine, n = 3) leflunomide, and 3.6% (n = 1) adalimumab and infliximab, respectively. Except when MTX and ETA were combined, the incidence of IBD was reduced in patients receiving MTX and greater in patients receiving ETA. IBD incidence was also greater in those using leflunomide or sulfasalazine.

The JIA group exhibited a greater incidence of IBD than the general population, and the ratio of CD to UC was noticeably higher, suggesting a particular phenotype of IBD. Using MTX as a pretreatment appeared to be protective. IBD cannot be prevented by ETA treatment, and IBD development may potentially be made more likely in JIA patients using leflunomide and sulfasalazine.