Could a New Risk Score Revolutionize Kidney Transplant Waitlisting?
Every 14 minutes, someone in the US is added to the kidney transplant waiting list. But a surprising number never receive the life-saving organ they need. Current waitlisting practices, relying heavily on a single measure of kidney function, may be missing a critical opportunity to identify and prioritize patients who would benefit most from a transplant – and a new study suggests a way to change that.
The Limitations of eGFR: A One-Size-Fits-All Approach
For years, the primary criterion for kidney transplant eligibility has been an estimated glomerular filtration rate (eGFR) of 20 ml/min/1.73 m2 or less. While eGFR provides a snapshot of current kidney function, it doesn’t predict future risk. This means individuals with similar eGFR levels can have vastly different trajectories of disease progression. A younger patient with rapidly declining kidney function might be overlooked while an older patient with a stable, but low, eGFR is prioritized – a scenario that doesn’t always align with maximizing patient benefit.
Introducing the Kidney Failure Risk Equation (KFRE)
Researchers are now exploring a more nuanced approach, incorporating the kidney transplant waitlist with the Kidney Failure Risk Equation (KFRE). The KFRE, presented at ASN Kidney Week 2025, calculates a patient’s two-year risk of kidney failure based on four key factors: age, sex, urine albumin levels, and eGFR. This provides a more comprehensive assessment of individual risk, moving beyond a single point-in-time measurement.
How Does KFRE Compare to Current Practices?
A study analyzing data from over 10,000 US veterans with chronic kidney disease revealed significant differences between the two criteria. While 60% of patients met both the current eGFR threshold and a KFRE score of ≥25% risk, a substantial 20% qualified under only one. Notably, those qualifying solely based on KFRE were, on average, 18 years younger than those qualifying solely on eGFR (53 vs. 71 years). This suggests the KFRE could identify younger patients at high risk who might otherwise be delayed in the listing process.
Addressing Racial Disparities in Transplant Access
Perhaps even more compelling, the KFRE appears to have the potential to reduce racial disparities in access to kidney transplantation. The study found that using the KFRE criteria alone would lead to more males, and importantly, more individuals from minority groups – including Hispanic, Black, and Asian populations – being added to the waitlist. These groups often experience higher rates of kidney disease progression and historically have faced barriers to accessing transplantation. This isn’t simply about adding names to a list; longitudinal data (2006-2019) showed that patients identified by both criteria or KFRE alone experienced higher rates of successful transplants and lower mortality rates compared to those listed solely on eGFR.
The Role of Albuminuria and Diabetes
The inclusion of urine albumin levels in the KFRE is particularly significant. Albuminuria, the presence of protein in the urine, is an early indicator of kidney damage and is more prevalent in individuals with diabetes – a major risk factor for kidney failure. By factoring in albuminuria, the KFRE provides a more sensitive measure of kidney health, especially for those with diabetes and other comorbidities.
Looking Ahead: Personalized Transplantation and Predictive Modeling
The shift towards incorporating risk prediction into waitlisting criteria represents a broader trend in medicine: personalized care. Instead of treating all patients with the same diagnosis identically, clinicians are increasingly using data-driven tools to tailor treatment plans to individual needs. The KFRE is a prime example of this approach, leveraging predictive modeling to optimize the timing of kidney transplantation.
However, the KFRE isn’t a perfect solution. Further research is crucial to validate its effectiveness in diverse populations beyond veterans and to refine the risk thresholds. The University of Michigan team, led by Jennifer L. Bragg-Gresham, MS, Ph.D., is actively pursuing these investigations. The future of kidney transplantation may well involve even more sophisticated risk assessment tools, incorporating genetic factors, biomarkers, and lifestyle data to create a truly individualized approach to waitlisting and allocation.
What impact will these changes have on the lives of those waiting for a kidney? The potential to save more lives and reduce health inequities is substantial. Share your thoughts on the future of kidney transplantation in the comments below!
