OBJECTIVES: to study the frequency and specificity of sclera-specific and non-sclera-specific autoantibodies in the sera of patients with anterior non-infectious scleritis. METHODS: prospective study involving 25 patients examined at the sector of Cornea and External Disease of the Department of Ophthalmology and Immuno-Rheumatology Laboratory at Federal University of São Paulo/Paulista Medicine School, during one year. The diagnosis of scleritis was according to Watson and Hayreh's (1976) classification criteria. The exclusion criterion was infectious scleritis. All the patients underwent a full clinical and ophthalmologic evaluation, including serological tests for syphilis and tuberculosis investigation. The following autoantibodies were tested: rheumatoid factor, antinuclear antibodies, anticardiolipin antibodies, ANCA (anti-neutrophil cytoplasmic antibodies), anti-SS-A/Ro, anti-SS-B/La, anti-Sm, anti-DNA and anti-APF (antiperinuclear factor). For sclera-specific autoantibodies, sera of all patients were subjected to indirect immunofluorescence and Western blot assays, using human sclera from eye banks as a substrate. Sera from 25 healthy individuals were used as a normal control in the immunologic assays. RESULTS: as non-sclera-specific autoantibodies we detected one patient with positive rheumatoid factor, two patients with positive antinuclear antibodies, two patients with positive anticardiolipin antibody and two patients with positive anti-APF. Sclera-specific autoantibodies were detected by Western blot and immunofluorescence in the serum of two patients with scleritis. The two patients with sclera-specific autoantibodies did not show non-sclera-specific autoantibodies and also presented no evidence of autoimmune rheumatic disease. Normal controls were negative for all tested autoantibodies. CONCLUSIONS: Sclera-specific autoantibodies were detected solely in the serum of patients with isolated non-infectious anterior scleritis. Non-sclera-specific autoantibodies were observed in patients with scleritis associated with autoimmune rheumatic disease and in patients with isolated scleritis.
autoantibodies; scleritis; autoimmunity; autoantigens