Kidney paired donation provides just as good graft survival as other living donor kidney (LDK) transplants, according to new data published online ahead of print in the Clinical Journal of the American Society of Nephrology.
In a comparison of 2363 recipients from the National Kidney Registry, a large nonprofit LDK exchange organization, and 54,497 other LDK recipients (related or unrelated) serving as controls, graft failure (5% vs 6%, respectively) and mortality (9% vs 10%, respectively) were similar over 3.7 years of follow up, David Leeser, MD, of East Carolina University Brody School of Medicine in Greenville, North Carolina, and collaborators reported.
In addition, the investigators observed few differences between kidney paired donation recipients in the National Kidney Registry and similar exchange organizations. The team adjusted their models for donor factors (age, sex, Hispanic ethnicity, body mass index 30 kg/m2 or higher); recipient factors (characteristics mentioned above plus African-American race, diabetes, previous transplant, preemptive transplant, public insurance, hepatitis C, estimated glomerular filtration rate [eGFR], antibody depleting induction therapy, and transplant year); and transplant factors (zero HLA mismatch).
National Kidney Registry recipients had a 36% higher risk of delayed graft function (DGF), but this did not appear to affect outcomes up to 7 years after transplant, Dr Leeser’s team reported.
Registry recipients had a longer dialysis vintage (median 1.3 vs 0.5 years) and were more likely to have received a previous transplant (25% vs 12%) and to have a panel of reactive antibodies (PRA) exceeding 80 (21% vs 4%). They also had longer cold ischemia times (median 8.8 vs 1.0 hours) and a higher rate of DGF (5% vs 3%). Registry recipients had a higher proportion of female, black, older, and public insurance recipients.
“Even after transplanting patients with greater risk factors for worse post-transplant outcomes, nationalized paired donation results in equivalent outcomes when compared to control living donor kidney transplant recipients,” Dr Leeser’s team stated. “These results should reassure the larger transplant community that a national kidney paired donation program is a safe and effective way to treat patients with incompatible living donors.”
Transplanting patients with incompatible donors accounts for 12% of LDK transplants in the United States annually, the authors noted.
In an accompanying editorial, Bushra Syed, MD, and Joshua Augustine, MD, of Cleveland Clinic observed: “The NKR [National Kidney Registry] has led the way in technology and innovation, and outcomes demonstrate success for those classically disadvantaged for living donor transplant, including black recipients and those who are highly sensitized.”
A strength of the registry is its low rates of desensitization (less than 5%), but the study’s relatively short follow up time is a limitation, the editorialists wrote. Future studies with longer follow up times are needed to determine whether long-term survival is negatively affected by the greater cold ischemia time and DGF in the registry cohort, they stated.
Leeser D, Thomas A, Shaffer A, et al. Patient and Kidney Allograft Survival With National Kidney Paired Donation [published online January 28, 2020]. Clin J Am Soc Nephrol. doi: 10.2215/CJN.06660619
Syed B, Augustine JJ. The National Kidney Registry: Time to buy in? [published online January 28, 2020]. Clin J Am Soc Nephrol. doi: 10.2215/CJN.14581119