Clinical implications of elevated serum interleukin-6, soluble CD40 ligand, metalloproteinase-9, and tissue inhibitor of metalloproteinase-1 in patients with acute ST-segment elevation myocardial infarction.

BACKGROUND: Atherosclerosis is widely accepted as a chronic inflammatory disease. Research paid much attention to sensitive specific serum biomarkers for vulnerable plaques. The markers not only serve as diagnostic tools for the identification of patients with acute coronary syndrome (ACS), but also help us to identify high-risk patients. However, the existing data are limited and have been conflicting. HYPOTHESIS: Circulating interleukin-6 (IL-6), soluble CD40 ligand (sCD40L), metalloproteinase-9 (MMP-9), and tissue inhibitor of metalloproteinase-1 (TIMP-1) might correlate with the onset and the cardiac mortality of patients with ST-segment elevation myocardial infarction (STEMI). METHODS: Serum levels of IL-6, sCD40L, MMP-9, and TIMP-1 were measured by sandwich enzyme-linked immunosorbent assay (ELISA) in 263 patients with STEMI and 262 age- and gender-matched control subjects without coronary artery disease (CAD). The patients with STEMI were then followed prospectively for 24 mo for the occurrence of cardiac mortality. RESULTS: Compared with the control subjects, patients with STEMI exhibited higher levels of IL-6 (p<0.001), sCD40L (p<0.001), MMP-9 (p<0.001), TIMP-1 (p=0.045), and MMP-9/TIMP-1 ratio (p=0.007). Significant and positive correlations between MMP-9 and TIMP-1 (r=0.610, p