Human recombinant interferon alfa-2a for the treatment of Behcet's disease with sight threatening posterior or panuveitis

Background: Behcet's disease is a multisystem vasculitis of unknown origin. Standard treatment mainly comprises systemic immunosuppressive agents. Ocular involvement, mostly posterior uveitis with retinal vasculitis, leads to blindness in 20-50% of the involved eyes within 5 years. The efficacy of interferon alfa-2a was studied in patients with sight threatening posterior uveitis or retinal vasculitis. Methods: 50 patients were included in this open, non-randomised, uncontrolled prospective study. Recombinant human interferon alfa-2a (rhIFNalpha-2a) was applied at a dose of 6 million units subcutaneously daily. Dose reduction was performed according to a decision tree until discontinuation. Disease activity was evaluated every 2 weeks by the Behcets disease activity scoring system and the uveitis scoring system. Results: Response rate of the ocular manifestations was 92% (three non-responder, one incomplete response). Mean visual acuity rose significantly from 0.56 to 0.84 at week 24 (p<0.000 1). Posterior uveitis score of the affected eyes fell by 46% every week (p<0.001). Remission of retinal inflammation was achieved by week 24. Mean Behcet's disease activity score fell from 5.8 to 3.3 at week 24 and further to 2.8 at week 52. After a mean observation period of 36.4 months (range 12-72), 20 patients (40%) are off treatment and disease free for 7-58 months (mean 29.5). In the other patients maintenance IFN dosage is three million units three times weekly. Conclusions: rhIFNalpha-2a is effective in ocular Behcet's disease, leading to significant improvement of vision and complete remission of ocular vasculitis in the majority of the patients.