Clinical Relevance of Donor-Derived Cell-Free DNA in Monitoring Kidney Transplant Rejection

Area of Science:

• Nephrology
• Transplant Surgery
• Molecular Diagnostics

Background:

• Donor-derived cell-free DNA (dd-cfDNA) is a noninvasive biomarker for kidney transplant rejection.
• Its clinical utility in post-transplant monitoring requires further exploration.

Purpose of the Study:

• To evaluate the clinical interpretability of dd-cfDNA for rejection risk stratification.
• To assess the impact of integrating dd-cfDNA into clinical models for post-transplant monitoring.

Main Methods:

• Analysis of 922 plasma samples (472 retrospective, 450 prospective) collected around kidney biopsies.
• Development and validation of logistic regression models incorporating clinical data and dd-cfDNA levels.
• Application of likelihood ratios to estimate post-test probabilities of rejection and assess risk stratification impact.

Main Results:

• dd-cfDNA alone demonstrated strong rejection discrimination (AUCs 0.79-0.80).
• Combining dd-cfDNA with clinical parameters improved discrimination (AUCs 0.82-0.87).
• Integration of dd-cfDNA reclassified intermediate-risk samples, potentially avoiding 482 biopsies (91% protocol biopsies).

Conclusions:

• dd-cfDNA is strongly associated with kidney transplant rejection.
• Integrating dd-cfDNA into risk assessment models can refine rejection risk stratification.
• This approach shows potential for reducing unnecessary kidney biopsies in post-transplant surveillance.