Brook, Lauren

Abstract Background Extraintestinal manifestations (EIMs) of inflammatory bowel diseases (IBDs) are a common and debilitating feature of disease, occurring in up to 40% of patients with IBD, yet predicting who may develop them is difficult. The goal of our study was to better characterize which patients may be at highest risk of developing not only 1 EIM, but also multiple EIMs, across both diseases. Methods A retrospective study of participants enrolled in the SPARC IBD (Study of Prospective Adult Research Cohort with IBD) registry was performed, and demographic and clinical data were analyzed. A total of 1211 patients with data available on EIMs were included, and differences among variables with vs without EIMs were assessed. Results A total of 329 participants with at least 1 EIM were identified, compared with 882 participants without any EIMs. Crohn’s disease patients and women were more likely to have 2 or more EIMs (P = .005 and P ≤ .001, respectively). Participants with ocular manifestations were likeliest to have at least 2 EIMs (P ≤ .001). Even when diagnosis was controlled for, involvement of the right colon (P = .021) was predictive of IBD-associated arthritis across both diseases in a multivariate generalized linear model. Conclusions This is the first comprehensive large-cohort assessment of how EIMs relate to one another at the individual vs systems levels. Further, our analysis is the first to recognize specific locations of colon involvement associated with EIMs of IBD, regardless of IBD type. These results are important in identifying patients at risk of developing future EIMs and may help with risk stratification when choosing treatments.