Local synovial synthesis of oligoclonal measles virus antibodies and of smooth muscle antibodies in a case of atypical rheumatoid arthritis.

Abstract

A patient with atypical rheumatoid arthritis (RA) and local synovial synthesis of oligoclonal Ig[immunoglobulin]G in an arthritic knee joint is described. Measles virus-specific antibodies isolated from the synovial fluid (SF) were oligoclonal IgG proteins, but they constituted only a fraction of the total oligoclonal IgG of the SF. Smooth muscle antibodies were markedly increased in the SF compared with the serum and were associated with an electrophoretically restricted fraction of IgG. A local synovial synthesis of measles virus-specific antibodies and of smooth muscle antibodies apparently occurred within the affected joint of the patient.