Propensity score–based comparison of the graft failure risk between kidney transplant recipients of standard and expanded criteria donor grafts: Toward increasing the pool of marginal donors

Abstract

From a prospective and multicentric French cohort, we proposed an external validation study for the expanded criteria donor (ECD), based on 4833 kidney recipients transplanted for the first time between 2000 and 2014. We estimated the subject-specific effect from a multivariable Cox model. We confirmed a 1.75-fold (95% confidence interval [CI] 1.53-2.00, P < .0001) increase in graft failure risk if a given patient received an ECD graft compared to a graft from a donor with standard criteria (standard criteria donor [SCD]). Complementarily, we estimated the population-average effect using propensity scores. We estimated a 1.34-fold (95% CI 1.09-1.64, P = .0049) increase in graft failure risk among ECD patients receiving an ECD graft compared to receiving a SCD graft. With a 10-year follow-up, it corresponded to a decrease of 8 months of the mean time to graft failure due to ECD transplantation (95% CI 2-14 months). The population-average relative risk due to ECD transplantation and the corresponding absolute effect seem finally not so high. Regarding the increase of quality of life in transplantation, our study constitutes an argument to extend the definition of marginality by considering more grafts at high risk and thereby enlarging the pool of kidney grafts.

Renal transplants from older deceased donors: Is pre-implantation biopsy useful? A monocentric observational clinical study

“…The overwhelming majority of our ECD (84%) were “high risk” according to the above definition. Despite this donor connotation, our medium (in DKT) and long-term data (in SKT (1-4) and SKT (> 4) ) shows not inferior graft and patient survival in recipients of these donor grafts than that commonly described for ECD in general[ 9 , 10 ], and confirms the potential wealth of older donor organs. Survival figures did not change, too, by restricting survival analysis to donors older than 70 years, indicating that also very old donors may be safe, if renal function is permissive.…”

“…Survival figures did not change, too, by restricting survival analysis to donors older than 70 years, indicating that also very old donors may be safe, if renal function is permissive. Others have described similar survival in recipients of grafts from donors older than 75 years as compared to grafts from younger ECD[ 10 ], or in recipients of grafts from ECD donors which differed by decades in the range from 60 to 80 years[ 12 ].…”

“…DKT was proposed as a means to reduce discard rate of grafts from marginal donors (defined on the basis of vascular disease and/or older age)[ 34 ]; organs from these donors have been often perceived to offer inadequate function if used as SKT. Indeed, survival in time of these organs allocated to SKT is lower in comparison with grafts from younger, or standard, donors[ 9 , 10 ]. In one study early graft loss from any cause was 10.1% (4.2% from unexplained PNF) in recipients of ECD grafts against 4.1 (all causes) and 1.5 (PNF), respectively, in standard donor grafts[ 35 ]; these and other’s[ 36 ] figures in ECD transplants are not far from ours in all SKT (7.1% early loss for any cause, with 4.0% PNF).…”

“…Despite worse performance than transplants from young donors in terms of delayed graft function (DGF), primary non function (PNF), short and long term renal function and overall graft survival[ 2 - 4 ], transplants from ECD may offer a survival advantage in comparison with not-being transplanted and remaining on wait list, at least for specific patient categories[ 5 - 7 ]. In quantitative terms, several reports indicate that graft survival from adequately selected ECD may not be much lower as compared to grafts from “standard” donors[ 8 - 10 ]. In our series, a retrospective analysis of death-censored graft-survival of transplants from clinically suitable, i.e ., with preserved renal function and anatomy, donors older than 60 years was only 8.2% lower than that from younger than 60-year donors after 10 years (84.0% vs 92.2%).…”

Maybe ECD kidneys aren’t as bad as I thought?

“…In this issue of AJT , Querard et al estimate the population average effect of graft loss of an Extended Criteria Donor (ECD) kidney compared to Standard Criteria Donor (SCD) kidney . This manuscript can be best summarized as… “ Maybe ECD kidneys aren't as bad as I thought?”…”