SUMMARY
Experimental and clinicai studies on S-antigen (SAg) and other retinal specific antigens have demonstrated their importance not only in the pathogenesis of various endogenous uveitis but also in the elaboration of new forms of immunotherapy. The present study aims to analyze the profile of in vitro cellular immunity to bovine SAg and to two of its immunodominant peptides, peptide M and peptide G, in Brazilian patients with Behçet's disease (BD) with uveitis, Vogt-Koyan agi Harada 's disease (VKH), retinal vasculitis, BD without uveitis and in a contral group. The frequency of positive responses to SAg was 42%, 52%, RO%, 4 7% a n d 25% in patients with BD with uveitis, VKH, retinal vasculitis, BD without uveitis and in the contral group, respectively. The Fequency of positive responses to peptide M was 26%, 60%, 6% a n d 6%, respectively, and, top eptide G was 21 %, 30%, 80%, 6% a n d 6%, respectively. Although there was no statistically significant difference amongth e groups analyzed, the present study demons trated the importance of AgS in patients with endogenous uveitis. Patients with BD without uveitis recognized the whole molecule but not the peptides suggesting that there are different responses to diverse AgS epitopes making possible some speculation about the mechanisms of uveitis induction.