Predictive Value of Perfusate Cell-free DNA During Hypothermic and Normothermic Machine Perfusion of Donor Kidneys
Karim Bousnina, Julia S. Slagter, Yitian Fang, Ruben G. Boers, Joachim B. Boers, Sebastiaan Heidt, Wilfred F.J. van IJcken, Joost Gribnau, Robert C. Minnee, Martin J. Hoogduijn, Karin BoerBackground.
Cell-free DNA (cfDNA) is a potential biomarker for graft (dys)function during machine perfusion, but its ability to predict posttransplant outcomes in donor kidneys remains unclear.
Methods.
We analyzed perfusate cfDNA from 57 hypothermic machine-perfused (HMP) and 56 normothermic machine-perfused (NMP) deceased donor kidneys. Nuclear cfDNA and mitochondrial cfDNA (mt-cfDNA) were quantified and compared across immediate graft function (IGF), delayed graft function (DGF), primary nonfunction (PNF), and discarded kidneys. Methylated DNA sequencing was used to analyze the cfDNA methylome during HMP to identify differentially methylated regions between IGF and PNF kidneys. Associations with donor characteristics and transplant outcomes, including serum creatinine, estimated glomerular filtration rate, and DGF duration, were assessed.
Results.
Perfusate cfDNA concentrations during HMP were significantly higher in PNF kidneys (0.72 ng/µL) compared with both IGF (0.48 ng/µL) and DGF kidneys (0.43 ng/µL;
Conclusions.
cfDNA—especially mt-cfDNA—measured during machine perfusion is associated with posttransplant graft outcome during both HMP and NMP. Therefore, it may serve as a candidate biomarker that warrants validation in larger prospective studies.