Use of dd-cfDNA to Stratify Risk of Allograft Loss in African American Recipients

Despite advances in the modern era of kidney transplantation, the rates of allograft loss remain disproportionately higher among African American transplant recipients than among non-African American recipients. According to A. Langone and colleagues, biologic and socioeconomic risk factors are associated with the persistent racial disparities in outcomes. Donor derived-cell free DNA (dd-cfDNA), as a marker of cellular injury, has been shown to have value in risk stratification.

The researchers conducted a study designed to compare the distribution of dd-cfDNA, stratified by self-reported race, to ascertain whether dd-cfDNA is a predictor of increased risk for allograft failure. Results of the study were reported during a virtual poster session at the American Transplant Congress in a poster titled Value of dd-cfDNA When Considering Recipient Ethnicity to Further Help Risk Stratify Transplant Recipients.

Patients in the DART (Diagnosing Active Rejection in Kidney Transplant Recipients) study were followed for 2 years. During the first year following kidney transplantation, dd-cfDNA (AlloSure®, CareDx, Brisbane, California) was measured up to seven times. A total of 676 samples from African American patients were compared with 1307 samples from patients of other race/ethnicity. The researchers examined the cumulative distribution of dd-cfDNA in both cohorts.

Compared with the non-African American cohort, patients in the African American cohort had significantly higher cumulative distribution of dd-cfDNA: mean 0.69 among African Americans versus 0.45 among non-African Americans, P=.0006. Events of allograft rejection were more frequent among African Americans than in the non-African American cohort (P=.0159).

When considering the dd-cfDNA cumulative distribution function for the percentage change in estimated glomerular filtration rate (eGFR) stratified by race, African American patients had a significant improvement in eGFR compared with the non-African American patients following the clinical care intervention.

In summary the researchers said, “African American [ethnicity] is a significant risk factor for transplant recipients and 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 and quantification of risk, and help allow earlier intervention to improve the overall outcomes and eGFR when events occur.”

Source: Langone A, Fischbach B, Cohen D. Value of dd-cfDNA when considering recipient ethnicity to further help risk stratify transplant recipients. Abstract of a poster presented at the virtual American Transplant Congress (Abstract B-323), May 30, 2020.