The successful use of asialylated IgG as an immunogen and arthritogen in the rabbit.

Joint lesions, closely resembling the main features of those seen in rheumatoid patients, were produced by intra-articular injections of asialylated homologous IgG into presensitized rabbits. The inflammatory changes were characterized by areas of extremely dense chronic inflammatory cell infiltration, where the lymphocytes were often aggregated into lymphoid follicles. There were also signs of involvement of the contralateral, saline-injected knee. Formation of an experimental rheumatoid factor-like antibody, detected by its ability to agglutinate sheep erythrocytes sensitized with baboon IgG, was also demonstrated. In addition, the rabbits developed other manifestations associated with rheumatoid arthritis, namely increases in erythrocyte sedimentation rate, serum haptoglobin concentration and joint size.