The revised criteria for the classification of rheumatoid arthritis (RA) were formulated from a computerized analysis of 262 contemporary, consecutively studied patients with RA and 262 control subjects with From the Rheumatoid Arthritis Criteria Subcommittee of the Diagnostic and Therapeutic Criteria Committee of the American Rheumatism Association.

A model of arthritis was established by the injection of type II collagen into mice. Only mice bearing the H-2q haplotype were susceptible to the disease. Susceptibility was further mapped by the use of recombinant strains on the Iq locus. Type II collagen arthritis was observed in the (resistant X susceptible) F1 cross. Mice strains were designated high, intermediate, or low responders with respect to the anti-type II antibody levels measured by radioimmunoassay. Arthritis-susceptible strains were all classified as high antibody responders. The clinical and histological appearance of type II collagen arthritis in the mouse indicates that it may be a good animal model for the investigation of various immunogenetic traits in rheumatoid arthritis.

Relapsing polychondritis is a unique, rare autoimmune disorder in which the cartilaginous tissues are the primary targets of destruction but the immune damage can spread to involve noncartilaginous tissues like the kidney, blood vessels, and so forth. The manifestations of the disease can take many different forms and the pathogenesis is still unclear. It may occur in a primary form or it may be associated with other disease states. This article summarizes important aspects of the disease with a focus on recent information regarding clinical manifestations, disease associations, pathogenesis, and advances in therapeutics.