Prevalence of peripheral and extra-articular disease in ankylosing spondylitis versus non-radiographic axial spondyloarthritis: A meta-analysis

Abstract

Background: Peripheral disease (arthritis, enthesitis and dactylitis) and extra-articular disease (uveitis, psoriasis and inflammatory bowel disease) is common in ankylosing spondylitis (AS) and non-radiographic axial spondyloarthritis (nr-axSpA). So far, however, summary data on the prevalence are lacking. The objective of this meta-analysis was to assess the prevalence of peripheral and extra-articular manifestations in ankylosing spondylitis (AS) and nr-axSpA. Methods: We performed a systematic literature search to identify publications describing the prevalence of peripheral and extra-articular disease manifestations in patients with AS and nr-axSpA. We assessed the risk of bias and between-study heterogeneity, and extracted data. Pooled prevalence and prevalence differences were calculated. Results: Eight studies comprising 2236 patients with AS and 1242 with nr-axSpA were included: 7 of the studies were longitudinal cohort studies. There was male predominance in AS (70.4%, 95% CI 64.4, 76.0%) but not in nr-axSpA (46.8%, 95% CI 41.7, 51.9), which was independent of the prevalence of human leukocyte antigen (HLA)-B27. The prevalence of HLA-B27 was similar in AS (78.0% (95% CI 73.9, 81.9%) and nr-axSpA (77.4%, 95% CI 68.9, 84.9%)). The pooled prevalence of arthritis (29.7% (95% CI 22.4, 37.4%) versus 27.9% (95% CI 16.0, 41.6%)), enthesitis (28.8% (95% CI 2.6, 64.8) versus 35.4% (95% CI 6.1, 71.2)). dactylitis (6.0% (95% CI 4.7, 7.5%) versus 6.0% (95% CI 1.9, 12.0%)), psoriasis (10.2% (95% CI 7.5, 13.2%) versus 10.9% (95% CI 9.1, 13.0%)) and inflammatory bowel disease (4.1% (95% CI 2.3, 6.5%) versus 6.4% (95% CI 3.6, 9.7%)) were similar in AS and nr-axSpA. The pooled prevalence of uveitis was higher in AS (23.0% (95% CI 19.2, 27.1%)) than in nr-axSpA (15.9% (95% CI 11.8, 20.4%)). Conclusion: Peripheral and extra-articular manifestations are equally prevalent in AS and nr-axSpA, except for uveitis, which is slightly more prevalent in AS. These data provide evidence for the largely equal nature of disease manifestations in nr-axSpA and AS.