Why are some people more likely to develop polychondritis than others?

Not known: It is a chronic inflammatory condition involving the cartialge. Its cause is unknown. It is felt to be autoimmune and people can have antibodies to cartilage and collagen. There is an assocaition of other autoimmune disorders - systemic vasculitis, inflammatory eye disease, thyroid disease, sjogren's, systemic lupus and inflammatory bowel disease.