An analysis of 372 patients with anterior uveitis in a large Ibero-American cohort of spondyloarthritis: the RESPONDIA Group.

Objectives: This study analysed the frequency of anterior uveitis (AU) and its correlations in a large cohort of patients with spondyloarthritis (SpA).
Methods: A common protocol of investigation was prospectively applied to 2012 SpA patients in 85 centres from 10 Ibero-American countries. Clinical and demographic variables and disease indexes were investigated. Categorical variables were compared by χ2 and Fisher's exact test, and continuous variables were compared by ANOVA or Kruskal-Wallis test. A value of p<0.05 was considered significant.
Results: AU was referred by 372 SpA patients (18.5%). AU was statistically associated with inflammatory low back pain (p<0.001), radiographic sacroiliitis (p<0.001), enthesopathies (p=0.004), urethritis/acute diarrhoea (p<0.001), balanitis (p=0.002), hip involvement (p=0.002), HLA-B27 (p=0.003), and higher C-reactive protein (p=0.001), whilst it was negatively associated with the number of painful (p=0.03) and swollen (p=0.005) peripheral joints, psoriatic arthritis (p<0.001), psoriasis (p<0.001), nail involvement (p<0.001), and dactilitis (p=0.062; trend). No association with gender, race, and indices (disease activity, functionality and quality of life) was observed. Logistic regression showed that ankylosing spondylitis (p=0.001) and HLA-B27 (p=0.083; trend) was significantly associated with AU, while extra-articular manifestations (predominantly psoriasis) were negatively associated (p=0.016).
Conclusions: Anterior uveitis is a frequent extra-articular manifestation in SpA patients, positively associated with axial involvement and HLA-B27 and negatively associated with peripheral involvement and psoriatic arthritis.