Virologic studies in rheumatoid arthritis.

Comparison of virus antibody titers in JRA and matched controls failed to implicate rubella, measles, parainfluenza type 1 or Epstein-Barr viruses. Neither RNA viruses or mycoplasma were detected in rheumatoid synovial cell cultures by 3H-uridine incorporation. Mycoplasma were not isolated from rheumatoid synovial membranes or cell cultures using the large specimen-broth culture procedure. The balance of available evidence, including our own, suggests that mycoplasma are not involved in RA. Viruses, however, are better candidates, in spite of similar generally negative studies to date, because methods for detecting known latent infection in animals and in vitro are still in their infancy. Those that are known have not yet been comprehensively applied to RA. Thus, supported by indirect evidence from animal models and human diseases like polyarteritis, the hypothesis that viruses are involved in the pathogenesis of RA remains attractive, although direct evidence is still lacking.