US Kidney Transplants Grow in Number and Success

Mitchel L. Zoler, PhD

August 24, 2021

Kidney transplantation has recently been happening at a record pace and with unprecedented success despite patients having more risk factors than ever before.

During 2016-2019, US centers performed kidney transplants in nearly 77,000 patients, a jump of almost 25% compared with 4-year averages of about 62,000 patients throughout 2004-2015. That works out to about 15,000 more patients receiving donor kidneys, Sundaram Hariharan, MD, and associates reported in the New England Journal of Medicine in a review of all US renal transplantations performed during 1996-2019.

Coupled with the volume uptick during this 24-year period were new lows in graft losses and patient deaths. By 2018, mortality during the first year following transplantation occurred at about a 1% rate among patients who had received a kidney from a living donor, and at about a 3% rate when the organ came from a deceased donor, nearly half the rate of 2 decades earlier, in 1996. Rates of first-year graft loss during 2017 were also about half of what they had been in 1996, occurring in about 2% of patients who received a living donor organ and in about 6% of those who got a kidney from a deceased donor during 2017.

"Twenty years ago, kidney transplantation was the preferred option compared with dialysis, and even more so now," summed up Hariharan, a senior transplant nephrologist and professor of medicine and surgery at the University of Pittsburgh Medical Center and first author of the report. Kidney transplantation survival at US centers "improved steadily over the past 24 years, despite patient variables becoming worse," he said in an interview.

Kidney Recipients Are Older, More Obese, and Have More Prevalent Diabetes

During the period studied, kidney transplant recipients became on average older and more obese, and had a higher prevalence of diabetes; the age of organ donors grew as well. The prevalence of diabetes among patients who received a kidney from a deceased donor increased from 24% during 1996-1999 to 36% during 2016-2019, while diabetes prevalence among recipients of an organ from a living donor rose from 25% in 1996-1999 to 29% during 2016-2019.

The improved graft and patient survival numbers "are very encouraging trends," said Michelle A. Josephson, MD, professor and medical director of kidney transplantation at the University of Chicago, who was not involved with the report. "We have been hearing for a number of years that short-term graft survival had improved, but I'm thrilled to learn that long-term survival has also improved."

The report documented 10-year survival of graft recipients during 2008-2011 of 67%, up from 61% during 1996-1999, and a 10-year overall graft survival rate of 54% in the 2008-2011 cohort, an improvement from the 42% rate in patients who received their organs in 1996-1999, changes Hariharan characterized as "modest."

These improvements in long-term graft and patient survival are "meaningful, and particularly notable that outcomes improved despite increased complexity of the transplant population," said Krista L. Lentine, MD, PhD, professor and medical director of living donation at Saint Louis University. But "despite these improvements, long-term graft survival remains limited," she cautioned, especially because of risks for substantial complications from chronic immunosuppressive treatment including infection, cancer, glucose intolerance, and dyslipidemia.

The analysis reported by Hariharan and his associates used data collected by the Scientific Registry of Transplant Patients, run under contract with the US Department of Health & Human Services, which has tracked all patients who have had kidney transplants at US centers since the late 1980s, said Hariharan. The database included just over 362,000 total transplants during the 24-year period studied, with 36% of all transplants involving organs from living donors with the remaining patients receiving kidneys from deceased donors.

Living Donations Still Stagnant; Deceased-Donor Kidneys Rise

The data showed that the rate of transplants from living donors was stagnant for 2 decades, with 22,525 patients transplanted during 2000-2003, and 23,746 transplanted during 2016-2019, with very similar rates during the intervening years. The recent spurt in transplants during 2016-2019 compared with the preceding decade depended almost entirely on kidneys from deceased donors. This rate jumped from the steady, slow rise it showed during 1996-2015, when deceased-donor transplants rose from about 30,000 during 1996-1999 to about 41,000 during 2012-2015, to a more dramatic increase of about 12,000 additional transplants during the most recent period, adding up to a total of more than 53,000 transplants from deceased donors during 2016-2019.

"I strongly recommend organs from living donors" when feasible, said Hariharan. "At some centers, a high proportion of transplants use living donors, but not at other centers," he said.

It's unknown why transplants using organs from deceased donors has shown this growth, but Hariharan suggested a multifactorial explanation. Those factors include growth in the number of patients with end-stage renal disease who require dialysis, increased numbers of patients listed for kidney transplant, new approaches that allow organs from older donors and those infected with pathogens such as hepatitis C virus or HIV, greater numbers of people and families agreeing to donate organs, and possibly the opioid crisis that may have led to increased organ donation. The number of US centers performing kidney transplants rose from fewer than 200 about a quarter of a century ago to about 250 today, he added.

"Immuno Bill" Guarantees Medicare Coverage for Immunosuppression

Hariharan voiced optimism that graft and patient survival rates will continue to improve going forward. One factor will likely be the passage in late 2020 of the "Immuno Bill" by the US Congress, which among other things mandated ongoing coverage starting in 2023 for immunosuppressive drugs for all Medicare beneficiaries with a kidney transplant. Until then, Medicare provides coverage for only 36 months, a time limit that has resulted in nearly 400 kidney recipients annually losing coverage of their immunosuppression medications.

Hariharan and coauthors called the existing potential for discontinuation of immunosuppressive drug an "unnecessary impediment to long-term survival for which patients and society paid a heavy price."

"Kidney transplantation, especially from living donors, offers patients with kidney failure the best chance for long-term survival and improved quality of life, with lower cost to the health care system," Lentine said in an interview. Despite the many positive trends detailed in the report from Hariharan and coauthors, "the vast majority of the more than 700,000 people in the United States with kidney failure will not have an opportunity to receive a transplant due to limitations in organ supply." And many patients who receive a kidney transplant eventually must resume dialysis because of "limited long-term graft survival resulting from allograft nephropathy, recurrent native disease, medication nonadherence, or other causes." Plus many potentially transplantable organs go unused.

Lentine cited a position statement issued in July 2021 by the National Kidney Foundation that made several recommendations on how to improve access to kidney transplants and improve outcomes. "Expanding opportunities for safe living donation, eliminating racial disparities in living-donor access, improving wait-list access and transport readiness, maximizing use of deceased-donor organs, and extending graft longevity are critical priorities," said Lentine, lead author on the statement.

"For many or even most patients with kidney failure transplantation is the optimal form of renal replacement. The better recent outcomes and evolving management strategies make transplantation an even more attractive option," said Josephson. Improved outcomes among US transplant patients also highlights the "importance of increasing access to kidney transplantation" for all people with kidney failure who could benefit from this treatment, she added.

Hariharan and Lentine had no relevant disclosures. Josephson has been a consultant to UCB and has an ownership interest in Seagen.

N Engl J Med. 2021;385:729-43. Abstract

This article originally appeared on MDedge.com, part of the Medscape Professional Network.

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