24 - Antigen-induced Arthritis

Abstract

Antigen-induced arthritis in the rabbit is very similar to human rheumatoid arthritis (RA) in regard to histopathology. The formation of lymphoid follicles and synovial hypertrophy are prominent features, and like RA, the synovitis is persistent, lasting many months to years. The response of antigen-induced arthritis in the rabbit to drug therapy is similar to that in RA, unlike the commonly used rodent models of arthritis in which NSAIDs display disease-modifying activity. This chapter reviews the processes and mediators involved in antigen-induced arthritis and their implications in the understanding of the pathogenesis of RA. It focuses on the rabbit model of antigen-induced arthritis, although comparisons to antigen-induced arthritis in other species are also made. Antigen-induced arthritis has served as a useful model for the study of mechanisms and mediators involved in the pathogenesis of RA. Similarities of antigen-induced arthritis in the rabbit to RA include (1) the synovial histopathology, (2) the chronicity of disease, (3) antibody and T-cell responsiveness to cartilage components, and (4) the levels of inflammatory mediators in diseased joints. In particular, studies investigating the role of infiltrating leukocytes have given insights into the mechanisms involved in both the acute and chronic aspects of the disease.