Analysis of increased urinary acid glycosaminoglycans in a patient with relapsing polychondritis

We analysed the composition of glycosaminoglycans (GAGs) found in an increased amount in the urine from a patient with relapsing polychondritis (RP) by means of electrophoresis, since to our knowledge no analytical studies on the composition of GAGs in the urine from the patients with RP have been performed. Unexpectedly, the major GAGs detected in increased amount in the urine were found to be dermatan sulfate (DS) and hyaluronic acid (HA), the excretion of which correlated with the activity of the disease. Both DS and HA are the major components not of the cartilage but of the skin. Therefore, our findings suggest that the increased GAGs in RP are derived from skin or other tissues containing these GAGs rather than from the cartilage, unless there is an extensive cartilage destruction.