Methods. Synovial tissue specimens were obtained from patients with RA or patients with osteoarthritis (OA) who were undergoing joint replacement surgery, and synovial MCs were enzymatically dispersed. Cultured synovium-derived MCs were generated by culturing synovial cells with stem cell factor, and receptor expression was analyzed using fluorescenceactivated cell sorting. Mediators released from MCs were measured using enzyme immunoassays or enzymelinked immunosorbent assays.
Results. Primary synovial MCs and cultured synovium-derived