Autoreactivity against matrilin-1 in a patient with relapsing polychondritis.

Relapsing polychondritis (RP) is a rare inflammatory disease of cartilage. Chondritis of the auricular, nasal, and tracheal cartilages predominates in this disease, suggesting a response to a tissue-specific antigen. One potential antigen is matrilin-1, a cartilage matrix protein found uniquely in the tracheal, auricular, and nasal cartilage of adults. We describe herein a patient with RP who had both a humoral and a cellular immune response directed toward the cartilage matrix protein matrilin-1.