Presence of antibodies specific to cartilage-type collagen in rheumatoid synovial tissue.

Synovial membranes of rheumatoid arthritis patients were examined by fluorescence microscopy for the presence of cells producing different classes of immunoglobulins and for the incidence of antibodies to human collagens. IgG and IgM immunoglobulins were detected while IgA, IgD and IgE were absent. When consecutive tissue sections were incubated with tetramethylrhodamine isothiocyanate-labelled collagen preparations, prominent cellular and extra-cellular staining was observed only with cartilage-derived Type II collagen.