Use of “synovial” cell cultures in the search for virus in rheumatoid arthritis

Synovial cells obtained from rheumatoid and nonrheumatoid subjects were grown in culture for periods up to 5 months. No spontaneous degeneration, suggestive of latent viral infection, was observed in the rheumatoid cultures. No significant difference could be demonstrated between multiplication of Newcastle disease virus in rheumatoid and nonrheumatoid cultures. No virusinterfering or ‐inactivating activity could be demonstrated in the culture fluid from rheumatoid synovial cultures.