[Anti-Scl-70 antibodies in systemic scleroderma].

We looked for anti-Scl-70 and anti-centromere antibodies in 109 patients (26 men and 83 women). Mean age was 43 +/- 15 years. Forty patients had systemic sclerosis according to ARA criteria. The extension of cutaneous involvement was defined by using Barnett and Coventry criteria: 12 patients were type I (sclerodactyly), 20 type II (acrosclerosis) and 8 type III (diffuse scleroderma). Among the 12 patients with type I, there were 8 cases of CREST syndrome defined as follows: presence of sclerodactyly, Raynaud's phenomenon and 2 of the 3 following criteria: oesophageal dysmotility, calcinosis, telangiectasia. Other organ involvement was recorded. Control patients had idiopathic Raynaud's phenomenon (n = 22), other connective tissue diseases (n = 20), and miscellaneous diseases (n = 28). Ninety-nine patients were prospectively included in this study. Patients' sera were stored at -20 degrees C. Ten previously stored sera obtained from patients with systemic sclerosis were also analyzed. Immunological tests were performed simultaneously and with no information on the diagnosis. When antinuclear antibodies were detected by indirect immunofluorescence, double immunodiffusion and immunoblotting were performed. Anti-Scl-70 antibodies were detected in systemic sclerosis only: 1 of 12 type I, 11 of 20 type II and 4 of 8 type III. One serum negative by immunodiffusion was positive using immunoblotting. We found that the specificity of anti-Scl-70 antibodies for systemic sclerosis was 100 p. 100 and their sensitivity 40 p. 100. There was a correlation between the presence of anti-Scl-70 antibodies and the presence of antinuclear antibodies (p less than 0.05) and the extent of cutaneous involvement (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)