Assessment of the Utility of Kidney Histology as a Basis for Discarding Organs in the United States: A Comparison of International Transplant Practices and Outcomes

Abstract

BackgroundMany kidneys donated for transplant in the United States are discarded because of abnormal histology. Whether histology adds incremental value beyond usual donor attributes in assessing allograft quality is unknown.MethodsThis population-based study included patients who received a deceased donor kidney that had been biopsied before implantation according to a prespecified protocol in France and Belgium, where preimplantation biopsy findings are generally not used for decision making in the allocation process. We also studied kidneys that had been acquired from deceased United States donors for transplantation that were biopsied during allocation and discarded because of low organ quality. Using donor and recipient characteristics, we fit multivariable Cox models for death-censored graft failure and examined whether predictive accuracy (C index) improved after adding donor histology. We matched the discarded United States kidneys to similar kidneys transplanted in Europe and calculated predicted allograft survival.ResultsIn the development cohort of 1629 kidney recipients at two French centers, adding donor histology to the model did not significantly improve prediction of long-term allograft failure. Analyses using an external validation cohort from two Belgian centers confirmed the lack of improved accuracy from adding histology. About 45% of 1103 United States kidneys discarded because of histologic findings could be accurately matched to very similar kidneys that had been transplanted in France; these discarded kidneys would be expected to have allograft survival of 93.1% at 1 year, 80.7% at 5 years, and 68.9% at 10 years.ConclusionsIn this multicenter study, donor kidney histology assessment during allocation did not provide substantial incremental value in ascertaining organ quality. Many kidneys discarded on the basis of biopsy findings would likely benefit United States patients who are wait listed.

A kidney discard decision strategy based on zero‐time histology analysis could lead to an unjustified increase in the organ turndown rate among ECD

“…However, our study shows that the ‘virtual’ graft survival and function at one and five years post‐transplant of an ECD cohort matched on discarded kidneys donor characteristics was similar to the global ECD cohort, suggesting that zero‐time histology may not be the major factor associated with graft survival and that strategy could lead to an unjustified increase in the organ turndown rate. That conclusion is also supported by a recent study evaluating zero‐time histology in the United States and France [27]. Given these findings, our transplant centre stopped the practice of using zero‐time biopsies to support the accept/decline decision.…”

Variations in deceased donor kidney procurement biopsy practice patterns: A survey of U.S. organ procurement organizations

“…5,7,8 Although early studies about the prognostic value of procurement biopsy findings demonstrated an apparent association between extent of glomerulosclerosis and post-transplant outcomes, multiple subsequent studies have suggested that these findings add little to other donor characteristics that are already taken into account. [9][10][11] The practice is further complicated by differences in how biopsies are performed and interpreted. For example, wedge biopsies have been reported to overestimate glomerulosclerosis, interstitial fibrosis, and tubular atrophy while frozen sections with hematoxylin and eosin staining do not provide visualization of subtle pathology that may become apparent when tissue is formalin-fixed and paraffin embedded.…”

Association between procurement biopsy findings and deceased donor kidney outcomes: a paired kidney analysis

“…Given the limited value of these biopsies, reducing the reliance on procurement biopsies during deceased donor kidney allocation is a necessary step to improve organ utilization without sacrificing organ quality assessment. A recent analysis comparing kidneys discarded in the United States to histologically matched kidneys transplanted in France (where procurement biopsy findings are not used to inform allocation or organ acceptance) showed that the French kidneys had excellent outcomes, suggesting that waitlisted patients would have benefited had the discarded American kidneys been accepted for transplantation [16]. In addition to improving kidney utilization, the reduction or elimination of procurement biopsies may also improve allocation efficiency by eliminating the time and cost associated with performing, processing and interpreting these biopsies.…”

“…Multiple procurement biopsies performed on the same kidney very often yield discrepant results, and findings on these biopsies do not approximate findings on gold standard biopsies performed after implantation [11][12][13][14]. Further, although procurement biopsy findings may be associated with post-transplant outcomes in unadjusted analyses, nephrosclerosis on these biopsies is not associated with graft longevity after accounting for donor characteristics already available during allocation such as age and comorbidities [10,[15][16][17][18][19][20][21][22]. However, these studies have been limited by selection biases, as kidneys with procurement biopsies showing more severe nephrosclerosis are less likely to be transplanted.…”