Issue 15

Clinical Question

How common is sacroiliitis in IBD and who has it?

Editor’s Bottom Line

Axial arthropathies may be more common than we think. Abdominal radiologists should be encouraged to routinely comment on the presence or absence of sacroiliitis and ankylosing spondylitis in patients with IBD.

Reference

Kelly OB, Li N, Smith M, et al. The Prevalence and Clinical Associations of Subclinical Sacroiliitis in Inflammatory Bowel Disease. Inflamm Bowel Dis. 2019; 25(6):1066–71; https://doi.org/10.1093/ibd/izy339

Synopsis

Previous estimates of the prevalence of sacroilitis in IBD have ranged from 2% and 45.7%. In this study, investigators retrospectively studied 316 consecutive IBD patients at Mount Sinai Hospital in Toronto who had undergone abdominal and pelvic computed tomography (CT) for any indication between 2006 and 2015. Two blinded readers examined images for signs of sacroiliitis and also analyzed patient demographics, IBD phenotype, and extraintestinal manifestations (EIMS) of IBD. Half of the patients were male and 74% had Crohn’s disease (CD).

Evaluation of CT imaging revealed sacroiliitis in 16% of patients, but radiologists had initially reported sacroiliitis in 16 of these 49 patients (33%). Thirty-three of the 49 patients had also had abdominal x-rays within three months of CT, which revealed ankylosing spondylitis (AS) in 64%. Independent predictors of sacroiliitis were male gender (odds ratio [OR], 1.8; P=0.04), known arthritis (OR, 4.7; P=0.0001), pain as a symptom of IBD, and inflammatory rather than fistulising or penetrating, CD (P=0.01). The prevalence of sacroilitis did not differ by IBD subtype.  Severity, location, and extent of disease did not affect the likelihood of sacroilitis.

The authors concluded that sacroiliitis is underdiagnosed in the IBD population.

Details

Study Design: Case-control
Funding: None
Allocation: Not applicable
Setting: Single tertiary care center
Level of Evidence: 4 (Oxford Levels of Evidence)

The summary and conclusion in this issue of E-mentoring in IBD pertains to the manuscript(s) being reviewed, and should be considered in the context of what is already known surrounding the topic and incorporated into practice as deemed appropriate by the individual learner.