IBD Frequently Observed in Early Axial Spondyloarthritis

Inflammatory bowel disease (IBD) occurs with an incidence of 1/100 patient-years in early spondyloarthritis and is associated with poor outcomes, fulfillment of modified New York criteria, familial history of IBD, and absence of human leukocyte antigen B27 (HLA-B27), according to a study published in The Journal of Rheumatology.

DESIR is a prospective, observational, multicenter, cohort study of French patients aged 18 to 50 with early inflammatory back pain lasting more than 3 months and less than 3 years, suggestive of axial spondyloarthritis (N=708). This study was designed to evaluate cohort factors associated with IBD for participants with and without IBD at baseline and at 5 years and incidence over 5 years of follow-up.

At baseline, 35 of 708 patients had IBD, for a prevalence of 4.94% (95% CI, 3.3-6.5). Multivariable analysis showed associations between IBD and history of uveitis (odds ratio [OR] 3.62 [1.95-6.74]), DKK-1 levels (OR [per unit] 1.03 [1.02-1.05]), and TNF serum levels (OR [per unit] 1.17 [1.08-1.26]), but not with phenotypic presentation (dactylitis, enthesitis, peripheral arthritis, and uveitis) or baseline serum levels of other cytokines.

At 5 years, 480 participants were analyzed, 58 of whom had IBD. At this point, multivariable analysis showed associations with the Bath Ankylosing Spondylitis Disease Activity Index (OR [per unit] 1.10 [1.05-1.16]; P =.04), fulfillment of modified New York criteria (OR 4.85 [2.23-10.57]; P =.04), sick leave (OR 1.01 [1.005-1.014]; P =.04), and smoking (yes/no; OR 2.79 [1.5-5.07]; P =.04).

No associations were found with bone mineral density, enthesitis, MRI scores, or psoriasis. Additionally, 23 incident IBD cases were recorded at an estimated occurrence rate of 0.95/100 (0.57-1.35) patient-years, and multivariable analysis showed that incidence was associated with familial history of IBD (OR 3.31[1.62 – 6.77]), HLA B27 (OR 0.36 [0.22-0.59]), and fulfillment of modified New York criteria (OR 3.35 [1.85-6.08]).

Strengths of the study include the large number of patients in the cohort and the 5-year prospective follow-up with many biological, clinical, and imaging evaluations. Limitations include the lack of systematic gut investigation, which avoids the recognition of asymptomatic gut inflammation, as well as the number of patients lost to follow-up and the low number of events, which could induce a lack of statistical power in analysis.

Nevertheless, study investigators were able to conclude that, “in patients with potentially early [spondyloarthritis] followed for 5 years, IBD is frequent, with an estimated annual incidence of 0.95/100 patients. IBD is associated with worse outcome, familial history of IBD, absence of HLA-B27 and fulfillment of modified New York criteria.”

Study funding was provided by unrestricted grants from both the French Society of Rheumatology and Pfizer Ltd, France.

Reference

Wendling D, Guillot X, Prati C, et al. Impact of gut involvement in patients with high probability of early spondyloarthritis. Data from DESIR cohort [published online June 1, 2019]. J Rheumatol. doi: 10.3899/jrheum.181326