Different roles of TNF inhibitors in acute anterior uveitis associated with ankylosing spondylitis: state of the art

The purpose of the present review was to provide a comprehensive picture of the efficacy of the different tumor necrosis factor (TNF)-α inhibiting agents in the treatment of acute anterior uveitis (AAU), the most common extra-articular manifestation of ankylosing spondylitis (AS). AS related, AAU may lead to severe visual impairment, due to frequent flare recurrences, anterior, and posterior segment complications and traditional treatment side effects. Considerably higher levels of tumor necrosis factor (TNF) have been assessed in the aqueous humor and inflamed joints of patients with AS. Anti-TNF drugs have shown efficacy in preventing relapses of rheumatological manifestations of spondyloarthropathies. Several studies have underlined the sustained efficacy of the monoclonal anti-TNF antibodies also in reducing the recurrence of anterior chamber flares in patients with AS-related AAU. On the other hand, retrospective studies and observational reports have indicated lower effectiveness and some paradoxical occurrence of uveitis following treatment with the soluble receptor agent etanercept. Growing evidence suggests that a prophylactic strategy could be advocated in subjects with frequent and recalcitrant attacks of AS-AAU. In this regard, the administration of monoclonal anti-TNF antibodies such as adalimumab (ADA) has been shown to significantly reduce the rate of AAU recurrences. Indeed, during ADA treatment about 90 % of patients have shown to remain completely free of attacks for the entire follow-up period, in most studies. Further studies are needed to confirm the long-term efficacy of TNF inhibitors in AS related AAU and also their role in preventing ocular complications and visual impairment.