Biopsy-Based Discard of Donor Kidneys May Be Misguided
Biopsies are of little value in determining overall risk of delayed organ function.
Methods other than biopsy are needed to help medical personnel determine whether to discard or transplant a kidney from a deceased donor, according to the findings of two studies published online ahead of print in the Clinical Journal of the American Society of Nephrology.
In one investigation, a team that included Bertram L. Kasiske, MD, of the Scientific Registry of Transplant Recipients (SRTR) and the Hennepin County Medical Center in Minneapolis, discovered that routine use of biopsies could lead to unnecessary kidney discards. The group came to this conclusion after examining biopsy reports from 83 kidneys that had been discarded in 2010 due to biopsy findings (cases), and comparing those with biopsy reports from 83 contralateral transplanted kidneys from the same donor (contralateral controls) and 83 deceased donors randomly matched to cases by donor risk profile (randomly matched controls).
Among the biopsies, 69% were wedge biopsies and 94% used frozen tissue. Dr. Kasiske's group found the biopsy reports to be of low quality, with the reports often not indicating amounts of tubular atrophy, interstitial inflammation, arteriolar hyalinosis, and acute tubular necrosis.
A second procurement biopsy was obtained in 64 of 332 kidneys (19.3%); Dr. Kasiske and his colleagues reported poor correlation between first and second procurement biopsies, with only 25% of the variability in glomerulosclerosis explained by biopsies being from the same kidney. The team also found that the percentages of glomerulosclerosis overlapped substantially among the discarded kidneys, the contralateral controls, and the randomly matched controls, at 17.1%, 9%, and 5%, respectively. A finding of glomerulosclerosis of more than 20% was the only biopsy result that was independently correlated with discard, suggesting that this biopsy finding was the only one used in acceptance decisions.
One-year graft survival was 79.5% in contralateral controls and 90.7% in randomly matched controls, compared with 91.6% among all deceased-donor transplants in the SRTR.
“If the discarded kidneys had been transplanted with the same graft survival as the transplanted kidneys from the opposite side, many patients may have benefited,” Dr. Kasiske pointed out in an accompanying statement from the American Society of Nephrology (ASN). “All together, these results question whether routine procurement biopsies result in discarding kidneys that could be acceptable for many of the patients who die waiting for a kidney transplant.”
In the other study, Chirag R. Parikh, MD, PhD, of Yale University in New Haven, Conn., and associates evaluated relationships between deceased-donor biopsy reports of acute tubular necrosis (ATN) and delayed graft function (DGF) in a multicenter study.
Among 651 kidneys from 369 donors and four organ-procurement organizations that had been biopsied and then transplanted between March 2010 and April 2012, ATN was reported in 110 (17%). A total of 262 recipients (40%) experienced DGF, and 38 (6%) experienced graft failure.
DGF occurred in nearly half (45%) of the kidneys with reported ATN, compared with 39% of the kidneys without ATN. No significant difference existed in graft failure for kidneys with ATN and without ATN (8% vs 5%).
Other than the finding of a modest association between DGF and kidneys donated after cardiac death, the study revealed no significant associations overall between pre-implant biopsy-reported ATN and the outcomes of DGF or graft failure, Dr. Parikh and coauthors reported.
“Biopsies are listed as the primary reasons for discarding deceased-donor kidneys; however, as [biopsies] currently related to reported acute kidney injury, they provide little utility for determining the overall risk of delayed organ function or even premature organ failure,” Dr. Parikh said in the ASN statement.