Original article
Serum levels of metalloproteinases-2 and -9 (MMP-2, MMP-9) – correlation with their expression in skin lesions in systemic sclerosis – the preliminary examination

The role of extracellular matrix metalloproteinases (MMPs) is implicated in pathogenesis of systemic sclerosis (SSc). The aim of present study was a comparison of serum levels of two metalloproteinases %u2013 gelatinases MMP-2 and MMP-9 with their expression in lesional skin biopsies from patients with systemic sclerosis. 10 patients with systemic sclerosis (6 with limited SSc and 4 with diffuse SSc) and 10 healthy volunteers without any skin disease were examined. Evaluation of serum levels of MMP-2 and MMP-9 was performed by ELISA method with R&D Systems. Expression of MMPs was determined by immunohistochemistry in DAKO En Vision detection system using immunoperoxidase method with mouse monoclonal antibodies. Mean serum levels of MMP-2 were not statistically different between SSc patients and control group or both clinical types of SSc (lSSc 245.2 ng/ml vs. dSSc %u2013 248.0 ng/ml) and control group (246.4 ng/ml vs. 248.0 ng/ml) (p>0.05). Mean serum level of MMP-9 was statistically higher in SSc patients compared to control group (857.7 ng/ml vs. 431.1 ng/ml; p<0.05). There were no significant differences in MMP-9 mean serum levels between patients with lSSc %u2013 837.2 ng/ml vs. dSSc %u2013 888.5 ng/ml (p>0.05). Statistically significant negative correlation was observed between serum concentrations of MMP-9 and duration of skin sclerosis (ρ = -0.860; p<0.02). Expression of both examined metalloproteinases was stronger in lesional skin in comparison to control group biopsies. Obtained results confirm important role of MMPs in the pathogenesis of systemic sclerosis.