LAUSR

OBJECTIVE The aim of this study was to determine whether there is any association with anti-tumor necrosis factor (TNF) agent administration and development of new-onset inflammatory bowel disease (IBD) in ankylosing spondylitis (AS) patients. METHODS Records of the patients who met 1984 modified New York criteria for AS between 1998 and 2016 at Rheumatology Department were evaluated retrospectively and data about the patients, IBD properties and medication were obtained. RESULTS Among 420 patients, 310 were male, the average age was 42.9 ± 1.3 years, average disease duration was 16.7 ± 10.4 years. Anti-TNF agents were in use by 154 patients, 52 patients were receiving etanercept (ETN), infliximab (INF), adalimumab (ADA), and golimumab (GO) treatments were ongoing in 50, 41, and 11 patients, respectively. New-onset IBD developed in 10 patients; 3 from the group treated with non-anti-TNF drugs (1.1%) and 7 from the group treated with anti-TNF agents (4.5%) (p = 0.042). No significant difference was detected between three anti-TNF agent forms in relation with the risk of IBD onset. In AS patients, existence of familial AS (OR 4.69 (95%CI 1.28-17.19, p = 0.020) and anti-TNF agent treatment (OR 4.17 (95%CI 1.06-16.38, p = 0.041) were independent risk factors for new-onset IBD development. CONCLUSION Despite the increased risk of new-onset IBD development during the course of AS, paradoxical response to anti-TNF drugs must also be considered as a source that triggers onset of IBD.