Does pre-emptive kidney transplantation with a deceased donor improve outcomes? Results from a French transplant network

What are the benefits of preemptive versus non-preemptive kidney transplantation? A systematic review and meta-analysis

Opting for a preemptive kidney transplant (PKT) can help avoid costs and morbidity associated with dialysis. However, while multiple studies have shown clinical benefits of PKT, other studies have not demonstrated this, leading to controversy in the literature regarding the exact benefits of PKT. Therefore, this study aimed to determine the clinical outcomes of PKT versus non-preemptive kidney transplantation (nPKT) in adult patients. Multiple databases were searched up to May 4, 2022. Independent reviewers selected studies for inclusion and extracted relevant data. Risk of bias was assessed using the Downs and Black checklist. Eighty-seven studies including 859,715 adult kidney transplant patients were included the review. The risk of patient death (relative risk [95% confidence interval] 0.74 [0.60-0.91]) was significantly lower in PKT versus nPKT patients for living donor (LD) transplants, whereas the risk of overall graft loss was significantly lower in PKT compared to nPKT patients for both LD (0.72 [0.62-0.83]) as well as deceased donor (DD) transplants (0.80 [0.69-0.92]). The evidence suggests that LD PKT patients have a lower risk of patient death and graft loss compared to nPKT patients, and DD PKT patients have a lower risk of graft loss than nPKT patients.

A novel allocation strategy for the difficult-to-allocate donor: audit of deceased donor kidneys utilised for preemptive recipients within Western Australia

Kidney donor allocation can occasionally be difficult in Australia given a small population spread over vast distances. Therefore, between 2017 and 2019 our service allowed transplantation from deceased donors into local (same-state) preemptive recipients, only if no well-matched dialysis-dependent transplant waitlist recipient was available. Transplantation using this novel allocation pathway was associated with good clinical and immunological outcomes.

Effects of Social Deprivation on the Proportion of Preemptive Kidney Transplantation: A Mediation Analysis

Social inequalities in health lead to an increased risk of chronic kidney disease and less access to renal transplantation. The objective of this study was to assess the association between social deprivation estimated by the fifth quintile of the European Deprivation Index (EDI) and preemptive kidney transplantation (PKT) and to explore the potential mediators of this association.

Methods

This retrospective observational multicenter study included 8701 patients who received their first renal transplant in France between 2010 and 2014. Mediation analyses were performed to assess the direct and indirect effects of the EDI on PKT.

Results

Among the 8701 transplant recipients, 32.4% belonged to the most deprived quintile of the EDI (quintile 5) and 16% received a PKT (performed either with a deceased- or living-donor). There was a significant association between quintile 5 of the EDI and PKT (total effect: odds ratio [OR]: 0.64 [95% confidence interval (CI): 0.55-0.73]). Living-donor kidney transplantation was the main mediator of this association (natural indirect effect: OR: 0.92 [0.89-0.95]). To a lesser extent, positive cytomegalovirus and hepatitis C serologies and blood group B were also mediators (respective natural indirect effects: OR: 0.98 [95% CI: 0.95-1.00], OR: 0.99 [95% CI: 0.99-1.00], and OR: 0.99 [95% CI: 0.98-1.00], P < 0.05).

Conclusions

Our study suggests that social deprivation is associated with a decreased proportion of PKT. This association might be mitigated by promoting living-donor transplantation.

Prolonged dialysis duration is associated with graft failure and mortality after kidney transplantation: results from the French transplant database

BACKGROUND

Kidney transplantation (KT) is the treatment of choice for end-stage renal disease. Preemptive KT (PKT) should be considered when glomerular filtration rate is <15 mL/min/1.73 m2 but European reports on the results of PKT and the effect of pretransplant dialysis are scarce.

METHODS

We analysed all first kidney-only transplants performed in adults in France between 2002 and 2012. A Cox multivariable model was used to investigate the association of PKT and of pretransplant dialysis time with the hazard of graft failure defined as death, return to dialysis or retransplant, whichever occurred first.

RESULTS

We included 22 345 patients, with a mean ± SD age at KT of 50.5 ± 13.4 years; 61.9% were men and 3112 (14.0%) received a PKT. Median time of follow-up was 4.7 years. Graft failure occurred in 4952 patients up to 31 December 2013. After adjustment for recipients' age and sex, primary kidney disease, donor type (living or deceased donor, expanded criteria donor), HLA mismatches, cold ischaemia time, centre and year of transplantation, PKT was associated with a decreased hazard of graft failure when compared with pretransplant dialysis [hazard ratio (HR) 0.57; 95% confidence interval (CI) 0.51-0.63], whatever the duration of dialysis, even in the first 6 months. The effect of PKT on the hazard of graft failure was stronger in living kidney donors (HR 0.32; 95% CI 0.19-0.55).

CONCLUSIONS

In France, PKT was associated with a lower risk of graft failure than KT performed after the initiation of dialysis, whatever the duration of dialysis.

Quantifying lead time bias when estimating patient survival in preemptive living kidney donor transplantation

Preemptive kidney transplantation is the preferred initial renal replacement therapy, by avoiding dialysis and reportedly maximizing patient survival. Lead time bias may account for some or all of the observed survival advantage, but the impact of this has not been quantified. Using the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry, we included adult recipients of living donor kidney transplants during 1998-2017. Patients were transplanted preemptively (n = 1435) or after receiving up to 6 months of dialysis (n = 712). We created a matched cohort using propensity scores, and accounted for lead time (dialysis and estimated predialysis) using left-truncated Cox models with the primary outcome of patient survival. The median eGFR at transplantation was 6.9 mL/min per 1.73 m² in the non-pre-emptive, and 9.6 mL/min per 1.73 m² in the preemptive group. In the matched cohort (n = 1398), preemptive transplantation was not associated with a survival advantage hazard ratio (HR) for preemptive vs non-pre-emptive 1.12 (95% confidence interval [CI] 0.79-1.61). Accounting for lead time moved the point estimates toward a survival disadvantage for preemptive transplantation (eg, HR assuming 4 mL/min per 1.73 m² /year eGFR decline, 1.21 [0.85, 1.73]), but in all cases the 95% CIs crossed 1. The optimal timing of preemptive living donor kidney transplantation requires further study.

Pre-emptive deceased-donor kidney transplant: A matched cohort study

INTRODUCTION

Currently, kidney transplantation is the treatment of choice for patients with kidney disease who require replacement therapy. Dialysis is a necessary step, but not mandatory prior to transplantation. There is the possibility of pre-emptive transplantation or transplantation in pre-dialysis, that is, without previous dialysis. The aim of the present study is to evaluate the result of our experience with a pre-emptive kidney transplant from a deceased donor.

MATERIALS AND METHODS

Retrospective, observational, matched cohort study. We compared 66 pre-emptive with 66 non pre-emptive recipients, who received a first renal graft performed at our centre, matched by age and gender of donors and recipients, time of transplant, immunological risk, immunosuppression and cold ischaemia time. Early graft loss, incidence of acute rejection, delayed graft function, renal function at 12 and 36 months and graft and recipient survival were assessed in this period.

RESULTS

The percentage of recipients who presented early graft loss, delayed graft function and acute rejection was similar in both groups. No differences were observed in their renal function at 12 and 36 months after transplantation, as well as the actuarial survival of patients (P=0.801) and grafts (P=0.693) in the studied period. The total calculated cost of the period on dialysis for the control group was 8,033,893.16 euros.

CONCLUSIONS

Pre-emptive transplantation can yield comparable outcomes to those for post-dialysis kidney transplantation, and results in better quality of life for patients with end-stage kidney disease, as well as a reduced cost.

Variation in Dialysis Exposure Prior to Nonpreemptive Living Donor Kidney Transplantation in the United States and Its Association With Allograft Outcomes

BACKGROUND

The impact of dialysis exposure before nonpreemptive living donor kidney transplantation on allograft outcomes is uncertain.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Adult first-time recipients of kidney-only living donor transplants in the United States who were recorded within the Scientific Registry of Transplant Recipients for 2000 to 2016.

FACTORS

Duration of pretransplantation dialysis exposure.

OUTCOMES

Kidney transplant failure from any cause including death, death-censored transplant failure, and death with allograft function.

RESULTS

Among the 77,607 living donor transplant recipients studied, longer pretransplantation dialysis exposure was independently associated with progressively higher risk for transplant failure from any cause, including death beginning 6 months after transplantation. Compared with patients with 0.1 to 3.0 months of dialysis exposure, the HR for transplant failure from any cause including death increased from 1.16 (95% CI, 1.07-1.31) among patients with 6.1 to 9.0 months of dialysis exposure to 1.60 (95% CI, 1.43-1.79) among patients with more than 60.0 months of dialysis exposure. Pretransplantation dialysis exposure varied markedly among centers; median exposures were 11.0 and 18.9 months for centers in the 10th and 90th percentiles of dialysis exposure, respectively. Centers with the highest proportions of living donor transplantations had the shortest pretransplantation dialysis exposures. In multivariable analysis, patients of black race, with low income, with nonprivate insurance, with less than high school education, and not working for income had longer pretransplantation dialysis exposures. Dialysis exposure in patients with these characteristics also varied 2-fold between transplantation centers.

LIMITATIONS

Why longer dialysis exposure is associated with transplant failure could not be determined.

CONCLUSIONS

Longer pretransplantation dialysis exposure in nonpreemptive living donor kidney transplantation is associated with increased risk for allograft failure. Pretransplantation dialysis exposure is associated with recipients' sociodemographic and transplantation centers' characteristics. Understanding whether limiting pretransplantation dialysis exposure could improve living donor transplant outcomes will require further study.

Preemptive second kidney transplantation is associated with better graft survival compared with non-preemptive second transplantation: a multicenter French 2000-2014 cohort study

The impact of preemptive second kidney transplantation (2KT) on graft and patient survival is poorly established. The association between preemptive 2KT (p2KT, N = 93) and outcomes was estimated in a multicenter French cohort of 2KT (N = 1314) recipients using propensity score methods. During the follow-up, there were 274 returns to dialysis and 134 deaths. p2KT was associated with lower death-censored graft loss (HR = 0.39 [0.18-0.88], P = 0.024) and graft failure from any cause including death (HR = 0.42 [0.22-0.80], P = 0.008). Similar associations were observed for death with a functioning graft, although not reaching statistical significance (HR = 0.47 [0.17-1.26], P = 0.13). There was a significant interaction between donor type and p2KT (P for interaction = 0.016). Indeed, p2KT was not significantly associated with the risk of graft failure from any cause including death in living donor 2KT (P = 0.39), whereas the association was substantial in the deceased donor subset (HR = 0.30 [0.14-0.64], P = 0.002). Of note, the adjusted graft survival of p2KT with deceased donor paralleled that of 2KT with living donor, either preemptive or not (93.8% vs. 88.6% at 4 years and 76.1% vs. 70.5% at 8 years, P = 0.13). This large French multicenter study analyzed using propensity scores suggests that p2KT is associated with better graft prognosis.

Preemptive kidney transplantation: has it come of age?

The benefits of preemptive kidney transplantation are manifold. By avoiding complications associated with dialysis, preemptive kidney transplantation offers significant benefits in terms of patient welfare and societal cost-saving. Patients transplanted preemptively also tend to enjoy better patient and graft survival, especially when done with a living-donor organ. While dialysis exposure limited to 6 to 12 months may not significantly impact post-transplant outcomes, longer period of dialysis has been shown to increase the risk of mortality, delayed graft function, acute rejection, and death-censored graft loss. The benefits of preemptive transplantation also extend to different age groups and end-stage kidney disease (ESKD) diagnoses. However, multiple barriers have prevented wider adoption of preemptive transplantation as the primary treatment of ESKD around the world. Timely preparation for ESKD and identification of living donors should be encouraged in all patients with advanced chronic kidney disease to increase the chance of preemptive transplantation.

The influence of low donor age, living related donation and pre-emptive transplantation on end-organ damage based on arterial hypertension after paediatric kidney transplantation

BACKGROUND

To date, no study has described the pre-transplant and transplant risk factors for end-organ damage based on arterial hypertension in children after kidney transplantation (KTX).

METHODS

A retrospective chart review was performed of 206 children with KTX between 1991 and 2007. Patients<120 cm were excluded as no validated percentiles for 24-h ambulant blood pressure monitoring (ABPM) exist. Complete data sets were available for 116 patients. Data were recorded at 12, 24 and 36 months post- KTX. We analysed the influence of donor age, age at transplantation, pre-emptive transplantation, living or deceased transplantation and glomerular filtration rate (GFR) on the presence of end-organ damage, ABPM, ABPM standard deviation score and the numbers of anti-hypertensives used.

RESULTS

Lower donor age and the decade of transplantation were associated with less detection of end-organ damage (P=0.001). A lower need for anti-hypertensive medication (P=0.001) was detected in children who received organs from living donors and from deceased donors with a donor age<35 years and who were transplanted pre-emptively. Low recipient age was the only factor associated with lower ABPM (P=0.001). In our study, the type of immunosuppressive regimen and the GFR had no influence on the blood pressure.

CONCLUSIONS

It may be speculated that the risk of arterial hypertension and associated end-organ damage in children after KTX could be reduced by using organs from young donors with an advantage for living related and pre-emptive donation.