Release of mitochondrial DNA correlates with peak inflammatory cytokines in patients with acute myocardial infarction

OBJECTIVE: The present study is an exploration of the dynamic changes of plasma mitochondrial deoxyribonucleic acid (mtDNA) and inflammatory level in patients with acute myocardial infarction (MI). METHODS: Thirty-eight patients with acute MI and 33 control participants were included in the study. Blood samples were collected on admission, 12 hours post-percutaneous coronary intervention (PCI), 24 hours post-PCI, and 48 hours post-PCI. White blood cell (WBC) count and C-reactive protein (CRP) level were determined. Plasma was isolated from whole blood. Plasma mtDNA was measured using real-time polymerase chain reaction, and tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were measured using enzyme-linked immunosorbent assay kits. Bivariate correlation analysis was used to find correlation between plasma mtDNA and inflammatory level on admission. RESULTS: Plasma mtDNA was significantly higher in patients with acute MI than controls on admission (p<0.01). Plasma mtDNA decreased significantly after PCI treatment (p=0.01). WBC count, TNF-α, IL-6 and CRP showed similar pattern: elevation after onset of acute MI and contraction after PCI treatment (p<0.05). Positive correlations between plasma mtDNA and WBC count (r=0.435; p<0.001), TNF-α (r=0.538; p<0.001), IL-6 (r=0.518; p<0.001), and CRP (r=0.524; p<0.001) were identified. CONCLUSION: Plasma mtDNA elevated after onset of acute MI and positive correlation was observed between plasma mtDNA and inflammatory level, suggesting that mtDNA may play a key role in inflammatory responses in patients with acute MI.