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 Creactive 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.