Kidneys From Donors With AKI Safe for Transplant, But Often Unused

Nancy A. Melville

January 14, 2020

Transplanted kidneys from deceased donors who had acute kidney injury (AKI) show no differences in short- or long-term failure, or graft rejection, compared with those that came from donors without AKI, in some of the strongest evidence on the issue to date.

Yet many organs from donors with AKI still go unused in the United States, according to the study authors.

"We estimate there may hundreds of kidneys with AKI each year that are going unused but could be transplanted," senior author Chirag Parikh, MD, PhD, said in a press statement.

"Therefore, we are urging the transplant community to bring AKI kidneys into the donor pool with more confidence," said Parikh, who is director of the Division of Nephrology at the Johns Hopkins University School of Medicine, in Baltimore, Maryland.

Previous research, including a recent study from Parikh's team reported by Medscape Medical News, has supported the use of select AKI kidneys in transplantation, and many centers do transplant such organs.

However, studies on the issue have often involved smaller sample sizes and data are meanwhile lacking on the allocation of such kidneys.

Comparing Transplanted Kidneys From Those With AKI to Those Without

For the new study, published online January 8 in JAMA Network Open by Caroline Liu, MHS, also of Johns Hopkins, and colleagues, researchers evaluated data from 6722 deceased donors with AKI and 15,310 deceased donors without AKI from 2010 to 2013 who donated at least one kidney for transplant.

AKI was defined as having at least a 50%, or 0.3-mg/dL, increase in terminal serum creatinine level from admission.

Using a 1:1 propensity score-matched analysis, donors with and without AKI, and their corresponding kidney recipients, were matched, allowing for accurate comparison of characteristics including age, sex, ethnicity, AKI stage, and other medical conditions.

The deceased donors were a mean age of 40.4 years; 63% were males, and most had AKI stage 1 (69%), followed by stage 2 (21%) and stage 3 (10%). Of the 25,323 recipients that were analyzed, 61% were males and their mean age was 52 years.

At a median follow-up of 5 years (range, 4-6), there were no significant differences between those who received AKI kidneys and the non-AKI kidneys in terms of death-censored graft failure (hazard ratio [HR], 1.01; 95% CI, 0.95 - 1.08) or all-cause graft failure (HR, 0.97; 95% CI, 0.93 - 1.02).

Those receiving AKI kidneys did have significantly higher rates of developing delayed graft function (29% vs 22%; P < .001), which the authors note is consistent with previous studies.

The findings were consistent regardless of the AKI stage of the donor.

Rates of primary nonfunction among recipients were low (120 of 25,323; 0.5%), regardless of donor AKI status.

The authors note that although delayed graft function is an important issue in transplantation, the outcomes are typically similar between AKI and non-AKI kidney recipients.

"Although delayed graft function requires interventions (eg, additional dialysis sessions, modified initial immunosuppression regimens, and closer recipient monitoring) during initial follow-up, the lack of sustained risk suggests that recovery after delayed graft function is comparable between AKI and non-AKI kidneys, without substantial long-term sequelae," they write.

More Than a Third of AKI Kidneys Go Unused

When further looking at the allocation of AKI kidneys, the authors found that among 17,468 (85%) of 20,550 AKI kidneys that were available and harvested over the 3-year study period, only 12,711 (61.8%) were transplanted.

Of the more than 7000 kidneys that remained, 3030 were never procured and 4757 were discarded after recovery.

"This means almost 8000 organs were either rejected after procurement or never obtained at all simply because the donors had acute kidney injury," Parikh said in the statement issued by Johns Hopkins.

The authors note the allocation rates are consistent with the national discard or rejection rate for all potential donor kidneys, which is approximately 18%, and the rate jumps to about 30% for AKI kidneys.

Nearly 9000 of the approximately 95,000 Americans with end-stage renal disease who are awaiting organs drop off the list each year because of death or deteriorating health, according to data from the US Department of Health & Human Services.

Meanwhile, the need for donor kidneys is rising at 8% per year, and the availability of organs is not increasing at a similar rate, according to data from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).

"From our study's findings, we believe that the transplant community should continue to use deceased donor AKI kidneys and consider research to investigate whether currently discarded AKI kidneys from deceased donors without substantial comorbidities can be used more effectively," the authors conclude.

The study received funding from the National Institutes of Health/NIDDK and the George M. O'Brien Kidney Center at the Yale School of Medicine. The authors have reported no relevant financial relationships.

JAMA Netw Open. 2020;3:e1918634. Full text

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