Initial biopsy of deceased donor kidneys not reliable for predicting post-transplant outcomes
Initial biopsies of deceased donor kidneys, also known as procurement biopsies, often provided information that was neither reproducible nor associated with allograft outcomes, according to a recently published study. Therefore, researchers contended that procurement biopsy results should not be the deciding factor as to whether a kidney is suitable for transplant.
“Much of our prior work has focused on understanding how to reduce the discard of deceased donor kidneys in order to address the organ shortage,” Syed Ali Husain, MD, MPH, assistant professor of medicine in the division of nephrology at Columbia University Irving Medical Center, told Healio Nephrology. “Currently, about one in five kidneys recovered for the purpose of transplantation is instead discarded, and procurement biopsy findings is the most commonly cited reason for discard. We wanted to better understand the utility of these biopsy findings, and identify limitations that clinicians considering organ offers should be aware of.”
Husain and colleagues considered 606 deceased donor kidneys that were transplanted at Columbia University Medical Center between 2006 and 2016 and that had multiple procurement biopsies performed before transplantation. Based on the information determined through biopsy (regarding presence of glomerulosclerosis, interstitial fibrosis and tubular atrophy and vascular disease), each kidney was assigned a score of 0 (“most favorable”) to 3 (“least favorable”). Kidneys were then categorized by histology as “optimal” or “suboptimal.” The association between biopsy histology and patient and allograft survival was also assessed.
On first biopsy, optimal histology was identified in 63% of transplanted kidneys vs. 82% on second biopsy. Researchers found no association between optimal histologic classification on first biopsy and likelihood of death-censored allograft survival when compared with suboptimal first biopsy histology. However, on second biopsy, optimal histology was associated with allograft survival (HR for graft failure = 0.54).
When considering only kidneys with optimal histology on the second biopsy, researchers observed no difference in death-censored allograft survival among those whose first biopsy showed suboptimal histology vs. those with optimal histology on both biopsies. Further, there was no association found between first biopsy results and post-transplant outcomes (either patient or allograft survival).
Syed told Healio Nephrology these results suggest standardizing both biopsy technique and interpretation “can help yield results that are more informative to organ offer decisions.” However, he said, the best way to standardize biopsies remains unclear. Pointing out the lack of information on whether core or wedge biopsies are more accurate, as well as the lack of clarity on how much impact training the interpreting pathologist has on biopsy utility, he argued that future research must be done “to determine the best and most efficient way to identify which kidneys should undergo further histologic assessment, and how to perform that assessment.”
Husain reiterated that unfavorable procurement biopsy histology should not be used alone to make organ use decisions. “Rather,” he said, “such findings may be the result of sampling error, and repeating a biopsy in a standardized fashion may help identify kidneys whose quality was underestimated by their first biopsies.” – by Melissa J. Webb
Disclosures: Husain reports no relevant financial disclosures.