Studies of isolated synovial lining cells of rheumatoid and nonrheumatoid synovial membranes

Abstract

Abstract Synovial membranes from patients with rheumatoid arthritis and other arthritides were digested with tryps.n to produce suspensions of synovial cells. The cells were stained by the direct fluorescent antibody technique for IgG, IgM and the β 1c (C3) component of complement, using fluorescein and rhodamine isothiocyanate‐labeled antisera. A characteristic diffuse staining pattern for IgG and β 1c was observed in the cytoplasm of the phagocytic lining cells of rheumatoid synovium. In seropositive patients, inclusions containing IgG, IgM, and β 1c were also stained in these cells. The role of these immunoglobulins, localized in the lining cells, is discussed in relation to rheumatoid inflammation.