Markers of collagen and basement membrane metabolism in sera of patients with progressive systemic sclerosis.

The concentrations of the amino terminal propeptide of type III procollagen, the 7S domain of type IV collagen, and the fragment P1 of laminin (PIIINP, 7S, and P1 respectively) and the activity of galactosylhydroxylysyl glucosyltransferase (GGT) in serum were evaluated as indicators of disease activity in a cross sectional study of 84 patients with progressive systemic sclerosis. The mean values of PIIINP, P1, and GGT were raised in progressive systemic sclerosis, 19-32% of patients having abnormal values of the various tests. PIIINP, measured with two different assays, and P1 were associated with active, acute, or subacute disease. GGT also correlated positively with some acute phase proteins in the whole group, without a clear association with the course of the disease. Arthritis was associated with increased PIIINP concentrations as well as with an increased activity of GGT. Kidney disease led to raised concentrations of the degradation products of PIIINP. Raynaud's phenomenon in the hands was related to increased PIIINP concentrations.