Risk Factors Of Uveitis In Ankylosing Spondylitis

OBJECTIVES:Ankylosing spondylitis(AS)is the chronic systematic disorder that usually affects axial skeleton,characterised by the sacroiliitis.Besides,it often affects spine catapophysis,soft tissue around the spine,peripheral arthrosis,and even exhibits extra-articular manifestations.Uveitis is the most common extra-articular manifestation in patients with ankylosing spondylitis(AS),occurring in 20%–30% of the patients with AS.It is reported that about 90% of the cases involve anterior uveitis while posterior uveitis occurs rarely.The prevalence and characteristics of uveitis in AS have been studied in previous literatures while its associated risk factors have not been clarified.Therefore,this study analyzed the risk factors of uveitis in patients with AS.METHODS:Investigatory targets were a total of 390 AS patients from Jiangsu Provincial Hospital of Integrated Traditional and Western Medicine,the First Affiliated Hospital of Soochow University and Shanghai Jiao Tong University Affiliated Sixth People’s Hospital over the entire period of 2015.All the patients with AS fulfilled the modified New York criteria.The history of uveitis was accepted only if diagnosed by ophthalmologists.Meanwhile,we have ruled out the patients with infectious uveitis or other systemic autoimmune rheumatic diseases(SARDs),such as psoriatic disease,inflammatory bowel disease,Reiter’s syndrome and so on.The AS patients accompanied with uveitis were enrolled in the uveitis group,while the others without uveitis were included in the non-uveitis group as control.RESULTS:Of 390 patients with AS(80.5% male,mean age 33.3 years),38(9.7%)had experienced one or more episodes of uveitis.The incidence rate for hip-joint lesion was obviously higher for patients with uveitis than the non-uveitis group(44.7% vs 22.2%;P<0.01).The number of peripheral arthritis was also larger for the uveitis group than non-uveitis group(2.18±0.23 vs 0.55±0.04;P<0.001).Meanwhile,patients with uveitis had a significantly higher level of antistreptolysin O(ASO)and circulating immune complex(CIC)than those without(P<0.05 and P<0.0001,respectively).However,there were no significant differences in disease duration,HLA-B27,erythrocyte sedimentation rate(ESR)and C-reactive protein(CRP)between the two groups.Binary logistic regression results showed that ASO(OR=12.2,95% CI: 3.6-41.3,P<0.01)and the number of peripheral arthritis(OR=4.1,95% CI: 2.6-6.3,P<0.01)are significantly associated with uveitis in AS.CONCLUSIONS:This study provides some evidence that hip-joint lesion,the number of peripheral arthritis,ASO and CIC may be associated with higher rates of uveitis in AS.The results of this comprehensive analysis suggest that the possible occurrence of uveitis in AS should not be neglected if the patients have those concomitant risk factors.