IBD-Associated Arthritis is Associated With Concomitant Autoimmune and Inflammatory Disorders

Background: Extraintestinal Manifestations (EIMs) are a common and potentially debilitating complication of Inflammatory Bowel Diseases (IBD) which often require additional treatment beyond those used to control intestinal disease. IBD-associated arthritis affects ∼ 25% of those with IBD and is associated with several factors including disease location, sex, and IBD type. Much remains unknown about other clinical factors that predict development of EIMs. We analyzed data from the LOCATION-IBD cohort to identify additional factors associated with IBD-associated arthritis. Methods: Demographic data, clinical data, and patient-reported outcomes were analyzed both in a univariate and multivariate manner. Continuous and categorical variables were assessed using Welch’s t-test and Fisher’s exact test, respectively. Multivariate generalized linear mixed models (GLMM) with penalized quasi-likelihood (PQL) were developed to further assess factors associated with IBD-associated arthritis. Results: 182 participants in the LOCATION-IBD cohort with (n=53) and without (n=110) joint EIMs and with joint pain of unclear etiology (n=19) were included in this analysis. Participants with joint EIMs were likelier to be female (p = 0.021), have Crohn’s disease (CD; p=0.027), have at least one concomitant autoimmune disorder (p=0.031), and have taken antibiotics in the 28-90 days prior to enrollment (p=0.003). No difference in age, race, ethnicity, or disease duration was observed between groups. In a multivariate GLMM-PQL comparing those with vs without joint EIMs, female sex (OR= 2.5, p=0.014), presence of concomitant autoimmune and inflammatory disorders (OR= 2.5, p=0.038), and CD relative to ulcerative colitis (OR= 2.9, p=0.026) were associated with the presence of joint EIMs; recent antibiotic use was no longer significant in the multivariate model (p=0.223). Conclusions: To our knowledge, this is the first analysis to recognize patients with IBD-associated arthritis are more likely to have concomitant autoimmune disorders. Further studies are needed to confirm this association, understand the mechanisms underlying the common pathogenesis of these concurrent disorders, and evaluate their impact on the treatment of IBD-associated arthritis.