Antibodies to Type II Collagen in Relapsing Polychondritis

Relapsing polychondritis is a disorder of unknown cause characterized by the destruction of cartilage. To test the hypothesis that immunologic mechanisms are involved in the pathogenesis of relapsing polychondritis, we analyzed the serum of 15 patients for the presence of antibodies to cartilage. Antibodies to Type II (cartilage) collagen were found in the serum of five patients at the time of acute symptoms. No antibodies were detected either to cartilage proteoglycan or to other collagen types. The antibodies were detected at the onset of the disease and their titers appeared to correlate with severity of disease. Circulating immune complexes were also detected in the serum of these patients. Our findings support an immunologic involvement in this condition. RELAPSING polychondritis is a disease manifested by recurring episodes of inflammation in cartilaginous tissue throughout the body. Pearson et al. suggested the name relapsing polychondritis in 1960 to emphasize its episodic nature leading to degeneration and replacement of cartilaginous structures by fibrous tissue.¹ The coexistence of various rheumatic and autoimmune diseases in 30 per cent of patients has led to the suggestion that an immunologic dysfunction may be involved in the pathogenesis of relapsing polychondritis.² Attempts to demonstrate anticartilage antibodies in the serum of these patients have yielded variable, but usually negative, results, and the putative antigen (or antigens) has.