Reproducibility of Deceased Donor Kidney Procurement Biopsies

Abstract

Background and objectives: Unfavorable histology on procurement biopsies is the most common reason for deceased donor kidney discard. We sought to assess the reproducibility of procurement biopsy findings.

Design, setting, participants, & measurements: We compiled a continuous cohort of deceased donor kidneys transplanted at our institution from 1/1/2006 to 12/31/2016 that had at least one procurement biopsy performed, and excluded cases with missing biopsy reports and those used in multiorgan transplants. Suboptimal histology was defined as the presence of advanced sclerosis in greater than or equal to one biopsy compartment (glomeruli, tubules/interstitium, vessels). We calculated κ coefficients to assess agreement in optimal versus suboptimal classification between sequential biopsy reports for kidneys that underwent multiple procurement biopsies and used time-to-event analysis to evaluate the association between first versus second biopsies and patient and allograft survival.

Results: Of the 1011 kidneys included in our cohort, 606 (60%) had multiple procurement biopsies; 98% had first biopsy performed at another organ procurement organization and their second biopsy performed locally. Categorical agreement was highest for vascular disease (κ=0.17) followed by interstitial fibrosis and tubular atrophy (κ=0.12) and glomerulosclerosis (κ=0.12). Overall histologic agreement (optimal versus suboptimal) was κ=0.15. First biopsy histology had no association with allograft survival in unadjusted or adjusted analyses. However, second biopsy optimal histology was associated with a higher probability of death-censored allograft survival, even after adjusting for donor and recipient factors (adjusted hazard ratio, 0.50; 95% confidence interval, 0.34 to 0.75; P=0.001).

Conclusions: Deceased donor kidneys that underwent multiple procurement biopsies often displayed substantial differences in histologic categorization in sequential biopsies, and there was no association between first biopsy findings and post-transplant outcomes.

Keywords: allografts; atrophy; biopsy; cohort studies; confidence intervals; deceased donor kidney; humans; kidney; kidney biopsy; kidney transplantation; probability; procurement; reproducibility of results; sclerosis; tissue and organ procurement; tissue donors; transplant pathology; vascular diseases.

Graphical abstract

Figure 1.

Flow diagram of study cohort. CUMC, Columbia University Medical Center; OPO, organ procurement organization.

Figure 2.

Concordance between histologic findings on first and second procurement biopsies. Agreement between first and second biopsies was poor overall, with strongest agreement for vascular disease (κ=0.17, concordance 59%), followed by interstitial fibrosis/tubular atrophy (κ=0.12, concordance 71%), and glomerulosclerosis (κ=0.12, concordance 44%).

Figure 3.

Unadjusted Kaplan–Meier curves of death-censored allograft survival on the basis of first procurement biopsy histology (log rank P=0.72) and second procurement biopsy histology (log rank P=0.002) showing that only second biopsy histology was associated with death-censored allograft survival.