Antibodies to ribonucleic acid in systemic lupus erythematosus.

Sera of 16 of 89 patients with systemic lupus erythematosus contained precipitating antibodies to RNA. These antibodies were found infrequently in patients with rheumatoid arthritis and Sjögren's syndrome, and not at all in patients with juvenile rheumatoid arthritis, myeloma, nor in normal individuals. These studies present evidence for the presence of antibodies to double-stranded RNA (both synthetic and viral). The fact that mammalian RNA's are probably single-stranded nucleotides suggests that these anti-RNA antibodies are directed primarily to a foreign, double-stranded RNA antigen.