Pre-transplant histology does not improve prediction of 5-year kidney allograft outcomes above and beyond clinical parameters

Abstract

Pre-implant kidney biopsy is used to determine suitability of marginal donor kidneys for transplantation. However, there is limited data examining the utility of pre-implant histology in predicting medium term graft outcome. This retrospective study examined kidney transplants over a 10-year period at a single center to determine if pre-implant histology can identify cases of eGFR ≤35 ml/min/1.73m at 5 year follow up beyond a clinical predictive logistic regression model. We also compared outcomes of dual kidney transplants with standard single kidney transplants. Of 1195 transplants, 171 received a pre-implant kidney biopsy and 15 were dual transplants. There was no significant difference in graft and patient survival rates. Median eGFR was lower in recipients of biopsied kidneys compared with standard kidney transplants (44 vs. 54 ml/min/1.73m, p < .001). Median eGFR of dual transplant and standard kidney transplants were similar (58 vs. 54 ml/min/1.73m, p = .64). Glomerular sclerosis (p = .05) and Karpinski Score (p = .03) were significant predictors of eGFR at 5-years in multivariate analysis but did not improve discrimination of eGFR ≤35 ml/min/1.73m at 5-years beyond a clinical prediction model comprising donor age, donor hypertension and terminal donor creatinine (C-statistic 0.67 vs. 0.66; p = .647). Pre-implant histology did not improve prediction of medium-term graft outcomes beyond clinical predictors alone. Allograft function of dual transplant kidneys was similar to standard transplants, suggesting that there is scope to increase utilization of kidneys considered marginal based on histology.

Assessing the discrimination of the Kidney Donor Risk Index/Kidney Donor Profile Index scores for allograft failure and estimated glomerular filtration rate in Ireland’s National Kidney Transplant Programme

“…As a result, the KDRI/KDPI is not likely to be reliable in isolation to predict graft failure or to decide on discarding donor organs in Ireland. This parallels our findings on histological features of pre-implant kidney biopsies [15].…”

Evaluation of donor kidneys prior to transplantation: an update of current and emerging methods

“…As a registry analysis, the study suffered from selection bias. Two more recent studies compared the predictive performance of a clinical score with the performance of a histological score and found no improvement in prediction of post‐transplant allograft survival beyond the moderate prediction provided by the clinical data . In 2006, Remuzzi et al .…”

Deceased Donor Procurement Biopsy Practices, Interpretation, and Histology-Based Decision-Making: A Survey of US Kidney Transplant Centers

“… 7 Multivariable analysis designed to isolate the impact of each lesion separately found that these findings lose significance when controlled for clinical variables, such as donor age. 24 , 25 Although it must be acknowledged that the outcome of grafts which are not transplanted as a result of biopsy results (“true positives”) is not known, comparison to outcomes from similar organs transplanted in Europe (where biopsy results are not available before transplant) suggests that many of these organs would provide benefit if transplanted. 10 …”