Clinical Associations of Uveitis in Axial Spondyloarthritis Group and Ankylosing Spondylitis Group: Do They Represent the Same Disease?

Abstract

Objective The aim of this study was to determine the prevalence and associated factors for uveitis in ethnic Chinese patients with axial spondyloarthritis (SpA) and ankylosing spondylitis (AS). Methods This was a cross-sectional study. Patients fulfilling the Assessment of SpondyloArthritis international Society axial SpA criteria were recruited consecutively from 3 rheumatology centers in Hong Kong from March 2014 to July 2017. Clinical and biochemical parameters were collected. History of uveitis was inquired from both history and medical records. All patients received lumbosacral spine x-rays and whole-spine and sacroiliac joint magnetic resonance imaging. Patients were defined as axial SpA if they fulfilled the Assessment of SpondyloArthritis international Society criteria and AS if they fulfilled the modified New York criteria. Clinical and radiological findings were compared between patients with and without uveitis in the 2 groups. Factors associated with uveitis were identified with univariate analyses and multivariate logistic regression analyses. Results Among 252 patients, 67 patients (26.6%) had a history of uveitis. The male-to-female ratio was 55.4 to 44.6. Disease duration was 12.3 ± 11.7 years. In the axial SpA group, multivariate regression showed that older age (odds ratio [OR], 1.05; P = 0.01), human leukocyte antigen B27 positivity (OR, 11.79; P = 0.01), and history of inflammatory bowel disease (OR, 9.74; P = 0.04) were positively associated with uveitis. In the AS group, multivariate regression showed that back pain duration (OR, 1.05; P = 0.01) and male sex (OR, 3.46; P = 0.03) were associated with uveitis. Conclusions Axial SpA represents a spectrum of diseases. Its clinical associations with uveitis should be distinguished from those of traditional AS.