Clinical significance of serum levels of matrix metalloproteinase-13 in patients with systemic sclerosis

Abstract

Objectives: To investigate the clinical significance of serum matrix metalloproteinase-13 (MMP-13) levels in patients with systemic sclerosis (SSc). Methods: Serum MMP-13 levels were determined by using a peptide substrate cleavage assay in 20 patients with diffuse cutaneous SSc (dcSSc), 20 with limited cutaneous SSc (lcSSc) and 10 normal controls. Results. The serum MMP-13 levels in patients with dcSSc or lcSSc were significantly lower than those in normal controls (53.4 ± 14.1 vs 73.2 ± 11.5 ng/ml, <0.0005; 59.4 ± 14.8 vs 73.2 ± 11.5 ng/ml, P <0.005, respectively), but there was no significant difference in the serum MMP-13 levels between patients with dcSSc and those with lcSSc. Disease duration prior to the diagnosis was significantly shorter in SSc patients with decreased serum MMP-13 levels than in those with normal levels (3.0 ± 2.2 vs 8.6 ± 7.6 yr, P <0.0005). In addition, serum MMP-13 levels were moderately correlated with the duration of the disease (r = 0.451, P <0.05). Though there was no significant difference in the frequencies of pulmonary fibrosis or reduced %DLco (diffusing capacity of lung for carbon monoxide), the frequency of reduced %VC (vital capacity) was significantly greater in patients with decreased serum MMP-13 levels than in those with normal levels (73 vs 24%, P <0.05). Conclusions: Matrix metalloproteinase-13 may be involved in the fibrotic process of SSc, especially in the initiation of fibrosis. The serum MMP-13 levels may serve as a useful marker for the severity of pulmonary fibrosis in patients with SSc. © 2006 Oxford University Press.