Arterial Intimal Fibrosis in Reperfusion Biopsy Correlates with Graft Function after Kidney Transplant

Introduction: Alterations to the procurement biopsy are one of the main reasons that kidneys are not suitable for transplant and are discarded. The literature on procurement and reperfusion biopsy is inconsistent and heterogeneous. The objective of this study is to describe the correlation of the different histological characteristics detected by the procurement and reperfusion biopsies in relation to graft function.

Methods: This is a retrospective cohort study of deceased donor kidney transplants performed from 2013 to 2017. All of the different histological components of procurement and reperfusion biopsies were analyzed with nonparametric tests and multivariate regressions. Graft function was expressed as glomerular filtration rate (GFR) at 1, 3, 6, and 12 months after transplant. All tests were based on a level of significance of α = 0.05.

Results: A comparison of procurement and reperfusion biopsies revealed that 60.4% of the grafts exhibited more arterial intimal fibrosis and 55.6% more arteriolar hyalinosis in the reperfusion biopsy than in the procurement biopsy. Arterial intimal fibrosis in reperfusion biopsy correlated with GFR at all time points, and it was the only histological characteristic of the reperfusion biopsy that remained significant in multivariate analysis. Glomerulosclerosis in the procurement biopsy correlated with graft function and remained significant in multivariate analysis, but only at 6 months. Arterial intimal fibrosis in the reperfusion biopsy is significantly associated with graft function independently of clinical characteristics.

Conclusion: Our study highlights the importance of arterial intimal fibrosis in predicting kidney function after transplant. Because arterial intimal fibrosis is a chronic change not related to ischemia-reperfusion injury, the differences between the 2 biopsies may be due to the biopsy technique. In order to increase the prognostic accuracy of the procurement biopsy, the technique should be improved to better evaluate the vasculature.