October 14, 2021
2 min read
The study was support by a grant from the FOREUM Foundation for Research in Rheumatology. van Straalen reports no other relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.
Enthesitis-related arthritis and a family history of autoimmune disease are key risk factors for inflammatory bowel disease in juvenile idiopathic arthritis, according to data published in Rheumatology.
The researchers additionally found data linking etanercept (Enbrel, Amgen) to a higher incidence of IBD regardless of whether it is combined with methotrexate.
“Until now, not much was known about risk factors and independent predictors for IBD in JIA,” Joeri W. van Straalen, a PhD student at Wilhelmina Children’s Hospital, University Medical Center Utrecht, in the Netherlands, told Healio Rheumatology. “Albeit a rare comorbidity, IBD strongly reduces quality of life in children and complicates the treatment of JIA. Therefore, specific information about which JIA patients run the highest risk of developing IBD was much desired.”
To examine the risk factors for IBD among children with JIA, van Straalen and colleagues analyzed data from Pharmachild, an ongoing international observational registry established in 2011. According to the researchers, this registry includes both retrospective and prospective clinical, laboratory and demographic data from patients with JIA treated at 85 centers within the Pediatric Rheumatology International Trials Organization (PRINTO) across 31 countries.
Joeri W. van Straalen
The researchers compared characteristics between 8,942 registry patients with and without IBD, using multivariable logistic regression analysis. The incidence rates of IBD events with various disease-modifying antirheumatic drugs were also determined, as well as the differences between the treatments, assessed as relative risks.
According to the researchers, 48 patients, or 0.54% of the total, developed IBD. Among patients with JIA who developed IBD, 47.9% were more often male — 47.9% versus 32% — and HLA-B27-positive — 38.2% compared with compared with 21%, than those without IBD. They were also older at JIA onset — a median 8.94 versus 5.33 years — and more often had a family history of autoimmune disease — 42.6% versus 24.4% — and enthesitis-related arthritis — 39.6% versus 10.8% — compared with those without IBD.
Based on multivariable analysis, the strongest predictors of IBD among these were enthesitis-related arthritis (OR = 3.68; 95% CI, 1.41-9.4) and a family history of autoimmune disease (OR = 2.27; 95% CI, 1.12-4.54).
The incidence of IBD with etanercept monotherapy (RR = 7.69; 95% CI, 1.99-29.74), etanercept plus MTX (RR = 5.7; 95% CI, 1.42-22.77), and infliximab (RR = 7.61; 95% CI, 1.27-45.57) was significantly higher than MTX monotherapy. The recorded incidence with adalimumab (Humira, AbbVie) was not significantly different (RR = 1.45; 95% CI, 0.15-13.89).
“Independent predictors for IBD in JIA are enthesitis-related arthritis and a family history of autoimmune disease,” van Straalen said. “We also observed that the incidence of IBD was significantly increased on etanercept therapy, regardless of whether combined with methotrexate. Physicians might consider opting for adalimumab instead of etanercept as a first-choice biological therapy in JIA patients with enthesitis-related arthritis and a family history of autoimmune disease in order to prevent the development of IBD.”