title: Prevalence of peripheral and extra-articular disease in ankylosing spondylitis versus non-radiographic axial spondyloarthritis: a meta-analysis.
abstract: 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.
  
  
  
  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.
  
  
  
  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 %)).
  
  
  
  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.
authors: Department of Clinical Immunology and Rheumatology, Amsterdam Rheumatology and immunology Center, Academic Medical Center/University of Amsterdam, Meibergdreef 9, 1105, AZ, Amsterdam, The Netherlands.
authors: Janneke J
authors: JJ
authors: de Winter
authors: Department of Clinical Immunology and Rheumatology, Amsterdam Rheumatology and immunology Center, Academic Medical Center/University of Amsterdam, Meibergdreef 9, 1105, AZ, Amsterdam, The Netherlands.
authors: Leonieke J
authors: LJ
authors: van Mens
authors: Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands.
authors: Désirée
authors: D
authors: van der Heijde
authors: Department of Clinical Immunology and Rheumatology, Amsterdam Rheumatology and immunology Center, Academic Medical Center/University of Amsterdam, Meibergdreef 9, 1105, AZ, Amsterdam, The Netherlands.
authors: Robert
authors: R
authors: Landewé
authors: Department of Clinical Immunology and Rheumatology, Amsterdam Rheumatology and immunology Center, Academic Medical Center/University of Amsterdam, Meibergdreef 9, 1105, AZ, Amsterdam, The Netherlands. d.l.baeten@amc.uva.nl.|Department of Experimental Immunology, Academic Medical Center/University of Amsterdam, Amsterdam, The Netherlands. d.l.baeten@amc.uva.nl.
authors: Dominique L
authors: DL
authors: Baeten
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D015995:Prevalence; D025241:Spondylarthritis / Q000473:pathology*; D013167:Spondylitis, Ankylosing / Q000473:pathology*
keywords: Ankylosing spondylitis; Axial spondyloarthritis; Extra-articular manifestations; Meta-analysis; Non-radiographic axial spondyloarthritis; Peripheral manifestations; Spondyloarthritis