In the US, more than 5,000 people die each year while waiting for a kidney transplant.
Dr. Chirag R. Parikh, director of the Program of Applied Translational Research at Yale and senior author of the study, says that "the waiting list has grown to over 100,000 patients as thousands more people are wait-listed each year than actually receive a transplant."
"In addition," Dr. Parikh adds, "the median time it takes for an adult to receive a transplant in the United States increased from 2.7 to 4.2 years between 1998 and 2008, and more than 5,000 people die each year while waiting for a kidney."
The Yale study is the largest multicenter observational study of its kind and looked at cases involving 1,600 deceased donors. The researchers looked for associations in the data between acute kidney injury (AKI) in donors and rates of kidney discard, and evaluated recipient kidney function for the first 6 months following transplantation.
Usually, donated kidneys with acute injury are discarded as a precaution to avoid transplant failure or delayed organ function. And the researchers, as might be expected, did find an association between AKI and organ discard. The injured kidneys were also associated with delayed graft function (DGF), which is the need for continued dialysis in the first week after transplantation.
However, the researchers found no link between kidneys donated from deceased donors and poor kidney transplant function 6 months later. In fact, the researchers found that transplant function at 6 months was worse for recipients with DGF who had received an uninjured kidney than it was for recipients of AKI kidneys.
"What we saw was, with worsening AKI in the donor, the 6-month outcome was actually better for recipients who experienced DGF," says Dr. Isaac E. Hall, investigator in the Program of Applied Translational Research at Yale School of Medicine and first author of the study.
What can explain the improved performance of the AKI kidneys?
Looking for a mechanism to explain this result, Dr. Hall suggests that the injured kidneys could perhaps develop "ischemic preconditioning," which may protect the organs from subsequent injuries.
An alternative explanation is that the successful AKI transplants were of "otherwise higher quality" than the rejected AKI transplants. However, the researchers did adjust their results for variables such as donor age and whether or not donors had two or more chronic conditions, so this should have been taken into account in the study's findings.
"There appears to be room to attempt more transplants using these AKI kidneys rather than throwing them away," says Dr. Parikh.
"Even if it only means a few dozen more kidney transplants each year, those are patients who would come off of the waiting list for transplants sooner and have much better survival than continuing on dialysis in hopes of seemingly higher-quality kidney offers, which may never come in time," he concludes.
Elsewhere on Medical News Today, we look at the new report from The Lancet and the International Society of Nephrology, which suggests that preventable AKI deaths could end by 2025. That report also finds that between 2.3 million and 7.1 million people who could have been kept alive with dialysis or kidney transplantation in 2010 died prematurely because treatment was unavailable.