Organ-specific autoantibodies in non-organ-specific autoimmune diseases with special reference to rheumatoid arthritis.

Sera from 367 patients with rheumatoid arthritis (RA) and from 102 patients with other non-organ-specific (NOS) autoimmune diseases were examined for the presence of organ-specific (OS) autoantibodies. The incidence of these OS autoantibodies was not increased in patients with NOS autoimmune diseases with the exception of thyroglobulin antibodies, which were significantly more frequent in RA (P less than 0.001) and in Sjögren's syndrome (P less than 0.05) patients than in normal controls. Investigation of 169 patients with OS autoimmune diseases did not reveal an increased prevalence of NOS autoantibodies. In RA patients, OS autoantibodies correlated with NOS autoantibodies (P less than 0.04) and with HLA-DR3 antigen (P less than 0.01).