Rubella-virus infection in juvenile rheumatoid arthritis.

Antibody activity against mumps, measles, polio, and rubella viruses was determined in patients with juvenile rheumatoid arthritis (J.R.A.), rubella-vaccine associated arthritis, adult rheumatoid arthritis, other chronic systemic disorders (e.g., systemic lupus and dermatomyositis), and in a matched population of normal, non-rheumatoid (control) children. The antibody levels against mumps, measles, and poliovirus were similar in all patients. Rubella-antibody levels in rheumatoid arthritis and other systemic disorders were similar to those observed in controls. The mean rubella-antibody levels in rubella-vaccine arthritis were 4 times higher than in controls. The IgM and IgG rubella-antibody levels in J.R.A. were found to be 4-6 times higher when compared to titres observed in the controls. Highest antibody levels were seen in younger children with J.R.A. Detection of rubella-virus antigen was attempted by immunofluorescence in the sediment smears of synovial fluid of patients with J.R.A., adult rheumatoid arthritis, and other non-rheumatoid joint diseases. Specific staining for rubella virus antigen was observed in the synovial fluid of 33 percent of patients with J.R.A. No antigen was detected in the synovial fluid from other patients. These observations suggest a possible role of rubella-virus infection in J.R.A.