Correlation Between Graft-derived CfDNA And Delayed Graft Function

BACKGROUND: Regular follow-up after renal transplantation is one of the key factors affecting the long-term survival and graft survival of patients.At present,serum creatinine(SCR),color Doppler ultrasound and biopsy are the main monitoring methods after renal transplantation,but there are some limitations.PURSOSES: This study aims to analyze the correlation between graft-derived cell free DNA(GcfDNA)in plasma and delayed graft function(DGF)in renal transplant recipients,and to evaluate its relatioonoship with the occurrence and outcome of DGF.METHODS: A total of 168 renal transplant recipients from July 1,2018 to March 1,2020 were enrolled in this study.We detected the level of GcfDNA in the peripheral blood of renal transplant recipients on the 1st,8th,15 th and 22 nd day after operation by using the droplet digital PCR(dd PCR)to study the level of GcfDNA in DGF group and non DGF group after renal transplantation,and to explore the risk factors of donor,recipient and operation.RESULTS: On the first day after operation,there was no significant difference in the level of GcfDNA(%)between DGF group and no-DGF group,but for severe DGF group(dialysis time>14 days),the level of GcfDNA(%)was significantly higher than that of mild DGF group(dialysis time≤14 days)(P=0.0026)and no-DGF group(P<0.05).There was no significant difference in GcfDNA(%)between mild DGF group and noDGF group(P=0.786),and there was no significant difference in creatinine at the same time point(P>0.05).In Kaplan Meier analysis,the one-year graft survival rates of severe DGF group and mild DGF group were 81.82% and 93.10%,respectively(P=0.290).Binary logistic regression analysis showed that the main risk factors of severe DGF were warm ischemia time(WIT)[ OR(95%CI)2.783(1.018-7.605);P=0.046],and the type of donation(OR=2.387)and donor BMI(OR=1.139)also increased the relative risk of severe DGF.CONCLUSION: Compared with creatinine,the level of GcfDNA(%)can better distinguish severe DGF group from no-DGF group and mild DGF group.Meanwhile,warm ischemia time more than 25 minutes may cause renal function damage,and may prolong the dialysis time in patients with cardiac death(DCD)and higher BMI.