Compositional changes of urinary acidic glycosaminoglycans in progressive systemic sclerosis.

The compositional changes of acidic glycosaminoglycans (AGAG) in the urine of progressive systemic sclerosis (PSS) patients were studied using chondroitinases and heparitinase in appropriate enzyme assays and by electrophoretic characterization. Daily urinary excretion of AGAG in patients with PSS was increased, when compared to normals. The proportion of urinary AGAG in PSS patients, which was undigested by chondroitinase-ABC (most probably representing heparan sulfates (HS)), increased significantly from the normal value. The substance was found to be mainly HS as determined by the electrophoretic pattern, thin-layer chromatographic analysis and by its susceptibility to heparitinase. After digestion of urinary chondroitin sulfate isomers with chondroitinases, the unsaturated disaccharides were mainly separated into 4-sulfated and 6-sulfated disaccharide units by paper chromatography. In all of the patients with PSS, the ratio of the unsaturated 4-sulfated disaccharide to the unsaturated disaccharide was higher than that in normal subjects. These observations indicate an abnormal turnover of AGAG in patients with PSS.