Relapsing polychondritis - pathogenic role of anti-native collagen type II antibodies. A case report with immunological and pathological studies.

A patient with relapsing polychondritis and Sjogren's syndrome is reported. Diagnosis was confirmed by ear cartilage biopsy. Antibodies against rat costal cartilage were present in the patient's serum. Antinative collagen type II antibodies were detected using a passive hemagglutination technique and the titer grossly correlated with the clinical course. Direct immunofluorescence using the patient's ear cartilage as a target suggested that anti-collagen antibodies might play a major pathogenic role in the course of relapsing polychondritis.