Elevated MMP-7 levels in patients with systemic sclerosis: correlation with pulmonary involvement

Background: Fibrosis is characterized by an excessive accumulation of connective tissue because of an imbalance between synthesis and I degradation of extracellular matrix proteins. Systemic sclerosis (SSc) is a prototypic chronic inflammatory disease leading to a severe fibrosis of the skin and many internal organs. Questions Addressed: We investigated whether serum MMP-7 levels reflect the activity of the fibrotic reaction in systemic sclerosis. Experimental Design: Serum samples were obtained from 123 patients with systemic sclerosis. MMP-serum levels of all patients with SSc were compared with age-matched healthy controls. Results: Significantly increased median serum MMP-7 levels were found in patients with SSc when compared with controls. The median MMP-7 serum level of patients with lung fibrosis (LF) was significantly higher compared with those without LE. Accordingly, patients with dyspnea and DLCO (diffusion capacity of the lung for carbon monoxide) levels below 60% showed significantly higher median MMP-7 levels. Conclusions: Elevated MMP-7 levels are associated with an advanced stage of SSc and LF. These data suggest that in SSc MMP-7 is involved in the process of fibrotic tissue remodelling.