CareDx, Inc. announced the publication of a new analysis from the Kidney Allograft Outcomes AlloSure Registry (KOAR) in the Journal of the American Society of Nephrology. The study establishes a link between elevations in its AlloSure Kidney donor-derived cell-free DNA (dd-cfDNA) test and increased risk of graft dysfunction and loss in kidney transplant recipients. This finding supports the role of AlloSure Kidney as a noninvasive tool for longitudinal risk stratification and clinical decision-making.

The second manuscript from KOAR evaluated the relationship between AlloSure Kidney dd-cfDNA and three-year kidney allograft outcomes in a multi-center cohort of 1,258 adult kidney transplant recipients across 56 U.S. centers. The study applied a multistate modeling framework to assess how longitudinal changes in AlloSure dd-cfDNA levels over time relate to subsequent allograft dysfunction and graft loss. During follow-up, approximately 36% of patients experienced dd-cfDNA elevation, transitioning from low to higher-risk states.

Key Findings from KOAR Analysis

The analysis demonstrated that transitions to elevated AlloSure levels were associated with significantly higher risks of allograft loss. The study also highlighted the ability of the test to detect subclinical injury prior to a measurable decline in estimated glomerular filtration rate (eGFR).

Additional findings include:

• Even a single elevation in AlloSure was associated with a measurable shift in clinical trajectory.
• Most AlloSure elevations occurred while kidney function remained preserved, demonstrating the ability to detect subclinical injury prior to measurable decline in eGFR.
• Patients with persistently low AlloSure levels experienced favorable outcomes, including low rates of rejection, dysfunction, and graft loss over three years.

Clinical Implications

"This analysis from the KOAR registry shows that elevations in dd-cfDNA are associated with meaningful differences in long-term allograft outcomes," said Jeffrey A. Klein, MD, Division of Nephrology, University of Kansas. "Importantly, we observed that many of these elevations occur while kidney function remains preserved, highlighting the potential for dd-cfDNA to provide earlier insight into allograft injury and help inform patient management."

Jonathan S. Bromberg, MD, PhD, Professor of Surgery at the University of Maryland School of Medicine, noted that the registry provides real-world evidence. "These findings suggest that tracking dd-cfDNA over time may offer a useful framework for risk stratification and longitudinal surveillance in kidney transplant recipients," he said.

Jeffrey Teuteberg, MD, Chief Medical Officer of CareDx, emphasized the biomarker's value. "These results from KOAR extend the growing body of evidence supporting AlloSure dd-cfDNA as a clinically meaningful biomarker in kidney transplantation," Teuteberg stated. "By enabling earlier identification of changes in allograft status, AlloSure may help clinicians assess risk over time and support more personalized patient management."