Antinuclear antibodies in systemic sclerosis. Clinical and ethnic associations

Antinuclear antibodies were detected, using a sensitive immunofluorescence test, in 96% of 160 patients with systemic sclerosis. Analysis of the patterns of staining revealed that a speckled pattern was commonest (66%), followed by nucleolar staining (37%). In 15% these two co-existed, and in 26% the speckling was of the fine, grainy type, indicative of Scl 70 antibody. Centromere antibody was found in 12%. Black patients made up 54% of the series, and centromere antibody was notably absent from this group, which also had more Scl 70 and nucleolar antibodies than did Indian patients. These serological findings correspond with the clinical features, there being far fewer blacks than Indians with limited cutaneous involvement. The ethnic differences found suggest a genetic influence on the expression of the disease and its auto-antibodies.