Don't Discard Donor Kidneys Based on Initial Biopsies Pam Harrison February 05, 2020
Concerns about the quality of deceased donor kidneys — based on initial biopsy findings — are frequently unfounded, resulting in many potentially viable donor organs being unnecessarily discarded, new research indicates.
"The most commonly cited reason for deceased donor kidney discard is unfavorable histology on procurement biopsies...accounting for 38% of all discards," write Ali Husain, MD, MPH, and colleagues in their article published online January 23 in the Clinical Journal of the American Society of Nephrology.
"Here we demonstrate in a large cohort of deceased donor kidneys that sequential procurement biopsies (obtained prior to transplantation) on the same kidney often yield considerably discordant results...[and that] misleading first biopsy results in missed opportunities for transplantation for candidates in the procuring donation service areas," they add.
In their retrospective cohort analysis, 85% of kidneys categorized as optimal on first biopsy were again categorized as optimal on the second biopsy, whereas only 27% of kidneys categorized as suboptimal on the first biopsy were again categorized as suboptimal on the second biopsy.
Importantly as well, graft survival was not affected by the status of the first biopsy, as graft survival was equivalent whether the first biopsy was optimal or suboptimal, as Husain explained.
In contrast, if the second biopsy was optimal, "the graft was only half as likely to fail as if the second biopsy was suboptimal ( P = .001)," he added.
"This is a key finding," Husain told Medscape Medical News , "because these biopsies are the number one reason why kidneys are thrown away — people think that the histology is suboptimal — but when the [first] biopsy says the kidney is suboptimal, it is probably wrong so we are misclassifying things," he emphasized.
The researchers also stress that even kidneys with suboptimal histology can be transplanted, with acceptable post-transplant outcomes, providing an overall benefit in appropriate recipients. Donated Kidneys Undergo Numerous Biopsies
A total of 1011 transplanted kidneys were included in the analysis. Of these, 60% had undergone multiple procurement biopsies, the first of which were done at an outside organ procurement organization.
A second round of confirmatory biopsies were done in New York City at the research team's local organ procurement organization.
Information regarding the degree of glomerulosclerosis, interstitial fibrosis/tubular atrophy, and vascular disease, as reported by the outside interpreting pathologist, was obtained for each biopsy. The degree of scarring in each of the three histologic compartments was assigned a score of 0 (most favorable) to 3 (least favorable) by the New York City research team.
"Optimal" histology was defined as having a score of ≤ 1 for all three biopsied compartments, and suboptimal biopsies scored higher on the research team's rating scale. Poor Agreement Between Sequential Biopsies
"Among the 606 kidneys that underwent multiple procurement biopsies, there was poor overall agreement between sequential biopsy findings in each of the three histologic compartments," explain Husain, of the Department of Nephrology at Columbia University Irving Medical Center, New York City, and coauthors.
For example, 63% of kidneys were classified as "optimal" on the first biopsy, whereas on the second biopsy, 82% of kidneys were classified as optimal.
In fact, only 55% of all kidneys analyzed had optimal histology on both biopsies.
Histologic concordance — that is, whether a kidney was judged to have optimal versus suboptimal histology in all three compartments on both the first and second biopsy — was 65%, Husain and colleagues point out.
The researchers also categorized the severity of scarring in the three histologic compartments to see how concordant the biopsies were in terms of degree of severity in each of the two biopsies taken.
In this specific analysis, they found that the two biopsies were in agreement 59% of the time when rating the degree of severity for vascular disease.
This was also true for 71% of the biopsies when rating the degree of interstitial fibrosis/tubular atrophy. For glomerulosclerosis, only 44% of the two procurement biopsies were judged to have the same degree of severity. Standardize Biopsy Procedures
Asked by Medscape Medical News if their findings suggest that biopsies should not be done by outside organ procurement organizations, Husain answered only "maybe."
"What we are saying here is that these biopsy data are not objective because they are not reliable or reproducible so the take-home from this part of the study is that biopsies should be done in a standardized fashion, even though we don't know what that standardized fashion should be," he elaborated.
To begin, the biopsies taken at the New York City center's local organ procurement organization are needle core biopsies, as opposed to wedge biopsies taken by outside organ procurement organizations, and the former may be more accurate than the latter.
The pathologists reading biopsies from the New York City center's local organ procurement organization center are also highly experienced, which may not be the case for pathologists reading biopsies from outside procurement centers, Husain noted.
"We know that something our organ procurement organization is doing seems to be right but we need more research to establish what the best way is to get this information, and once we know that, then we need to standardize it across the country so everyone is doing the best practice," he stressed.
"This is important because we know that transplantation provides a very large survival and quality of life advantage for patients," he concluded.
The authors have reported no relevant financial relationships.
Clin J Am Soc Nephrol. Published online January 23, 2020. Abstract
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Medscape Medical News © 2020 WebMD, LLC Send comments and news tips to . Cite this: Don't Discard Donor Kidneys Based on Initial Biopsies - Medscape - Feb 05, 2020. Authors and Disclosures
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