Composition of urinary glycosaminoglycans in a patient with relapsing polychondritis

Objectives: Several investigators have reported an increase in urinary glycosaminoglycans (GAGs) in patients with relapsing polychondritis (RP). The aim of this investigation is to analyze the composition and structure of urinary GAGs from a Brazilian patient with RP. Design and methods: The identification and structural analyses of the GAGs were made by electrophoresis and degradation with specific enzymes and identification of their disaccharides products by HPLC chromatography. Results: The disaccharide products formed from RP urinary chondroitin sulfate (CS) by action of chondroitin ABC lyase showed a substantial relative increase of nonsulfated disaccharides with a relative decrease of 6-sulfated disaccharides compared to control subjects. In addition, a significant change of the ratio of CS and heparan sulfate was also observed in the RP patient. Conclusion: The RP patient analyzed has shown a structural anomaly of the urinary CS and this may contribute to the diagnosis of this disease.