[Clinical characteristics of patients with ankylosing spondylitis and inflammatory bowel disease]

Objective: To analyze the clinical characteristics of patients with ankylosing spondylitis (AS) with inflammation bowel disease (IBD). Methods: AS patients fulfilling the 1984 modified New York diagnostic criteria were recruited in Chinese AS Prospective Imaging Cohort (CASPIC) consecutively from April 2016 to June 2017 in Chinese People's Liberation Army General Hospital by using smart management system for spondyloarthritis (SpAMS). The diagnosis of IBD was confirmed by tissue pathology via ileocolonoscopy. Demographic, clinical and biochemical data were collected. Results: In total, 893 patients with AS were recruited with the mean age 30.8 years. The majority were men (739, 82.8%). There were 64 (7.2%) patients concomitant with IBD. The mean age [(34.5±7.5) years vs. (30.5±8.8) years, P<0.001] was older and the disease duration [(10.8±6.9) years vs. (8.1±5.9) years, P=0.001] was longer in patients with IBD than patients without. Compared with patients without IBD, patients with IBD had more frequent involvement of the cervical spine [(21.9% (14/64) vs. 10.5% (87/829), P=0.006) and thoracic spine [29.7% (19/64) vs. 12.3% (102/829), P<0.001]. Uveitis [28.1% (18/64) vs. 16.4% (136/829), P=0.017] and psoriasis [7.8% (5/64) vs. 2.3% (19/829), P=0.009] were also more common in patients concomitant with IBD. In addition, patients with IBD had significantly higher scores in BASDAI (3.3±2.1 vs. 2.4±1.8, P<0.001), BASFI [2.2 (1.0,3.3) vs. 1.1(0.2,2.4), P<0.001)] and ASAS HI (7.1±4.3 vs. 5.3±3.7, P= 0.001) than patients without IBD. Conclusions: Compared with patients without IBD, AS patients concomitant with IBD have more severe disease activity and organ dysfunction. Furthermore, the uveitis and psoriasis are more frequently accompanied in AS patients with IBD.