Background: Within the modern era of kidney transplantation, African American (AA) transplant recipients continue to experience disproportionately higher rates of allograft loss. A combination of biologic and socioeconomic risk factors contribute to these persistent racial disparities. Donor derived-cell free DNA (dd-cfDNA), as a marker of cellular injury, has been shown to have increasing value in risk stratification, for patients with allograft injury and potential acute rejection. The aim of this study is to compare the distribution of dd-cfDNA, stratified by self-reported race, to determine whether dd-cfDNA can predict patients at higher risk for allograft injury.
Method: The DART study followed patients for two years, where dd-cfDNA (AlloSure®) was measured up to 7 times in the first-year post-transplant. 676 samples from AA patients were compared to 1307 non AA patient samples. The cumulative distribution of dd-cfDNA were assessed.
Results: The cumulative distribution of dd-cfDNA was significantly higher in AA patients compared to non AA patients (p=0.0006) see table 1. AA patients had more frequent events of allograft rejection compared to non AA patients (p = 0.0159).When considering the dd-cfDNA cumulative distribution function for the percentage change in eGFR stratified by Race; AA patients had a significant improvement in eGFR compared to non AA patients as a result of interventions to their clinical care.

Conclusion: AA as a significant risk factor for transplant recipients is associated with an increase in dd-cfDNA. The regular use of dd-cfDNA as part of post-transplant surveillance may assist in the assessment, quantification of risk and help allow earlier intervention to improve the overall outcome and eGFR when events occur.