Serum and urinary aminoterminal type III procollagen peptide in progressive systemic sclerosis: relationship to sclerodermal involvement, serum hyaluronan and urinary collagen metabolites.

Increased serum values of aminoterminal type III procollagen peptide and hyaluronan (hyaluronate) and enhanced urinary content of hydroxyproline and hydroxylsine containing polypeptides were demonstrated in patients with progressive systemic sclerosis (PSS). The serum propeptide level and the relative urinary excretion of hydroxyproline as polypeptides were related to the extent of cutaneous involvement. Elevated serum propeptide and hyaluronan values were seen in patients who progressed within the following 6 months. Patients with CREST syndrome had normal propeptide values. Reduced renal propeptide clearance is a likely cause of high serum levels of propeptide degradation products demonstrated in PSS. Serum propeptide seems to be a useful novel marker for disease activity and progression in PSS because of its linkage to the actual connective tissue metabolism.