Antibodies against SS-B/La and SS-A/Ro antigens in patients with primary Sjögren's syndrome.

An enzyme-linked immunosorbent assay for detection of serum antibodies against SS-B/La is described, and the frequency of anti-SS-B/La antibodies in 103 blood donors is tested. 67% of patients with primary Sjögren's syndrome (n = 21), verified by at least two abnormal tests for xerostomia as well as keratoconjunctivitis sicca (the Copenhagen criteria), were found to have IgG anti-SS-B antibodies, and 71% had anti-SS-A/Ro precipitating antibodies, when tested by Ouchterlony immunodiffusion. All patients with anti-SS-B/La antibodies had anti-SS-A/Ro antibodies. Anti-SS-A/Ro and -SS-B/La antibodies correlated with the presence of rheumatoid factor, antinuclear antibodies and hypergammaglobulinemia. The clinical manifestations of pseudolymphoma, Raynaud's phenomenon, fatigue and arthralgia, were more frequent in patients with anti-SS-B/La and/or -SS-A/Ro antibodies.