Variation of perioperative plasma mitochondrial DNA correlate with peak inflammatory cytokines caused by cardiac surgery with cardiopulmonary bypass

We found that plasma mtDNA might play a key role in CPB-induced post-operative inflammatory responses.

In the present study, we included 38 patients undergoing coronary artery bypass graft (CABG) to analyze their perioperative plasma mtDNA and levels of inflammatory cytokines. Blood samples were collected before aortic cross-clamping (T1), at the end of CPB (T2), 6 h post-CPB (T3), 12 h post-CPB (T4), and 24 h post-CPB (T5). Rt-PCR and specific ELISA kits were used to quantify the plasma mtDNA and inflammatory cytokines, respectively. Bivariate correlations analysis was used to check the correlations between plasma mtDNA and inflammatory cytokines respectively.

Results shown that plasma mtDNA elevated significantly at T2 and peaked at T4. Furthermore, plasma TNF-α, IL-6 and IL-8 levels significantly increased at T2 and peaked at T3 while IL-10 elevated and peaked at T2. Bivariate correlations analysis showed that the peak plasma mtDNA were positively correlated with the peak TNF-α (r = 0.677, P < 0.001), the peak IL-6 (r = 0.706, P < 0.001), the peak IL-8 (r = 0.584, P < 0.001) and the peak IL-10 (r = 0.565, P < 0.001).