Donor-derived cell-free DNA can discriminate acute rejection types after kidney transplantation / 中华肾脏病杂志

ABSTRACT

Objective:To explore the value of detecting plasma donor-derived free DNA (dd-cfDNA) fraction in distinguishing antibody mediated-rejection (ABMR) and T cell-mediated rejection (TCMR) of renal allografts.Methods:Patients with acute rejection confirmed by allograft biopsy in the First Affiliated Hospital of Medical College of Zhejiang University from December 1, 2017 to July 18, 2019 were retrospectively included. Based on pathological classification of Banff renal allograft rejection in 2017, the patients were divided into ABMR group and TCMR group, and the latter was subdivided into TCMR Ⅰ subgroup and TCMR Ⅱ subgroup. The second generation sequencing and target region capture were used to detect candidates' peripheral blood dd-cfDNA. The demographic and clinicopathological data of the two groups were compared. The receiver operating characteristic curve (ROC) was used to evaluate the differential value of plasma dd-cfDNA and serum creatinine levels in two kinds of acute renal allograft rejection.Results:A total of 60 patients with acute rejection of renal transplantation were enrolled in this study, including 42 patients in TCMR group and 18 patients in ABMR group. The plasma dd-cfDNA percentage (%) in the ABMR group was significantly higher than that in the TCMR group [2.33(1.19, 4.30)% vs 0.98(0.50, 1.82)%, P=0.001]. The absolute value of dd-cfDNA in ABMR group was obviously higher than that in TCMR group [0.94(0.60, 2.27) ng/ml vs 0.43(0.20, 0.96) ng/ml, P=0.003]. ROC analysis to discriminate TCMR from ABMR showed that, the area under the curve ( AUC) of dd-cfDNA% was 0.76(95% CI 0.64-0.88), when the threshold was 1.11%, the sensitivity and specificity were 88.89% and 59.52%, respectively; the AUC of absolute value of dd-cfDNA was 0.74(95% CI 0.61-0.86), when the threshold was 0.53 ng/ml, the sensitivity was 88.89% and the specificity was 54.76%. TCMR subgroups were further analyzed, there was no significant difference between TCMR subgroups on the absolute value and percentage of dd-cfDNA (both P>0.05); dd-cfDNA% in ABMR group was apparently higher than that in TCMRⅠ subgroups ( P=0.008) and TCMRⅡsubgroup ( P=0.030). The absolute value of dd-cfDNA in ABMR group was significantly higher than that in TCMRⅠsubgroups ( P=0.003). Conclusion:Plasma dd-cfDNA level may help to distinguish between ABMR and TCMR rejection.