Expression of interferon beta in synovial tissue from patients with rheumatoid arthritis: comparison with patients with osteoarthritis and reactive arthritis.

Background: IFNbeta may have immunomodulatory effects in rheumatoid arthritis (RA) and its increased production in RA synovium may be a reactive attempt to inhibit inflammation.

Objective: To determine the expression of IFNbeta in the synovial tissue of patients with RA, osteoarthritis, and reactive arthritis.

Methods: Synovial biopsy specimens were obtained by arthroscopy from patients with RA and disease controls for immunohistological analysis using a monoclonal antibody specific for IFNbeta.