Serial perioperative cell‐free DNA levels in donors and recipients undergoing living donor liver transplantation

Background Effect of anaesthesia and surgery on cell‐free DNA (cfDNA) is not known. Given that surgical stress augments inflammation and injury, we hypothesized that levels of cfDNA will fluctuate during perioperative period. Therefore, in this study serial perioperative cfDNA concentration was measured in donors and recipients undergoing living donor liver transplantation (LDLT). Methods Baseline, post‐induction, intraoperative and post‐operative plasma cfDNA levels were evaluated in 21 donors and recipients each, by Sytox green method. In addition, qPCR was performed in a subset of samples. Results Baseline cfDNA levels were higher in recipients (37.62 ng/ml) than in donors (25.49 ng/ml). A decrease in cfDNA was observed following anaesthesia induction in both recipients (11.90 ng/ml) and donors (10.75 ng/ml). When the kinetics of the cfDNA was monitored further, an increase was noted intraoperatively in donors (46.18 ng/ml) and recipients (anhepatic phase: 56.25 ng/ml, reperfusion phase: 54.36 ng/ml). cfDNA levels remained high post‐operatively. One recipient who developed post‐operative sepsis had the highest cfDNA level (94.72 ng/ml). Conclusion Plasma cfDNA levels are high in recipients indicative of liver injury. Lower cfDNA levels following induction may be attributed to the subduing effect of anaesthetic agents on cell death. High cfDNA levels seen in intra‐ and post‐operative phases reflect cellular trauma and inflammation. This similar pattern of fluctuation of cfDNA level in donors and recipients is suggestive of its possible utility as a surgical stress marker. In addition, comparable cfDNA levels in anhepatic and reperfusion phase reflect less ischemia reperfusion injury during LDLT.