Changes in pediatric renal transplantation after implementation of the revised deceased donor kidney allocation policy

Disparities in Access to Timely Waitlisting Among Pediatric Kidney Transplant Candidates

BACKGROUND AND OBJECTIVES

Kidney transplantation with minimal or no dialysis exposure provides optimal outcomes for children with end-stage kidney disease. We sought to understand disparities in timely access to transplant waitlisting.

METHODS

We conducted a retrospective, registry-based cohort study of candidates ages 3 to 17 added to the US kidney transplant waitlist 2015 to 2019. We defined "preemptive waitlisting" as waitlist addition before receiving dialysis and compared demographics of candidates based on preemptive status. We used competing risk regression to determine the association between preemptive waitlisting and transplantation. We then identified waitlist additions age >18 who initiated dialysis as children, thereby missing pediatric allocation prioritization, and evaluated the association between waitlisting with pediatric prioritization and transplantation.

RESULTS

Among 4506 pediatric candidates, 48% were waitlisted preemptively. Female sex, Hispanic ethnicity, Black race, and public insurance were associated with lower adjusted relative risk of preemptive waitlisting. Preemptive listing was not associated with time from waitlist activation to transplantation (adjusted hazard ratio 0.94, 95% confidence interval 0.87-1.02). Among transplant recipients waitlisted preemptively, 68% had no pretransplant dialysis, whereas recipients listed nonpreemptively had median 1.6 years of dialysis at transplant. Among 415 candidates initiating dialysis as children but waitlisted as adults, transplant rate was lower versus nonpreemptive pediatric candidates after waitlist activation (adjusted hazard ratio 0.54, 95% confidence interval 0.44-0.66).

CONCLUSIONS

Disparities in timely waitlisting are associated with differences in pretransplant dialysis exposure despite no difference in time to transplant after waitlist activation. Young adults who experience delays may miss pediatric prioritization, highlighting an area for policy intervention.

The unfinished journey toward transplant equity: an analysis of racial/ethnic disparities for children after the implementation of the Kidney Allocation System in 2014

BACKGROUND

Disparities in pediatric kidney transplantation (KT) result in reduced access and worse outcomes for minority children. We assessed the impact of recent systems changes on these disparities.

METHODS

This is a retrospective cohort study of pediatric patients utilizing data from the US Renal Data System (n = 7547) and Scientific Registry of Transplant Recipients (n = 6567 waitlisted and n = 6848 transplanted patients). We compared access to transplantation, time to deceased donor kidney transplant (DDKT), and allograft failure (ACGF) in the 5 years preceding implementation of the Kidney Allocation System (KAS) to the 5 years post-KAS implementation 2010-2014 vs. 2015-2019, respectively.

RESULTS

Compared to the pre-KAS era, post-KAS candidates were more likely to be pre-emptively listed (26.8% vs. 38.1%, p < 0.001), pre-emptively transplanted (23.8% vs. 28.0%, p < 0.001), and less likely to have private insurance (35.6% vs. 32.3%, p = 0.01), but these were not uniform across racial groups. Compared to white children, Black and Hispanic children had a lower likelihood of transplant listing within 2 years of first dialysis service (aHR 0.590.670.76 and 0.730.820.92, respectively) in the post-KAS era. Time to DDKT was comparable across all racial groups in the post-KAS era. Compared to white children, Black DDKT recipients have more 5-year ACGF (aHR 1.001.432.06 p = 0.05) while there was no difference in 3- or 5-year ACGF among LDKT recipients.

CONCLUSIONS

After KAS implementation, there is equity in time to DDKT. Pre-KAS increased hazard of ACGF among Black children has decreased in the post-KAS era; however, persistent disparities exist in time to transplant listing among Black and Hispanic children when compared to white children. A higher resolution version of the Graphical abstract is available as Supplementary information.

Deceased donor organ allocation in pediatric transplantation: A historical narrative

BACKGROUND

Since the earliest clinical successes in solid organ transplantation, the proper method of organ allocation for children has been a contentious subject. Over the past 30-35 years, the medical and social establishments of various countries have favored some degree of preference for children on the respective waiting lists. However, the specific policies to accomplish this have varied widely and changed frequently between organ type and country.

METHODS

Organ allocation policies over time were examined. This review traces the reasons behind and the measures/principles put in place to promote early deceased donor transplantation in children.

RESULTS

Preferred allocation in children has been approached in a variety of ways and with varying degrees of commitment in different solid organ transplant disciplines and national medical systems.

CONCLUSION

The success of policies to advantage children has varied significantly by both organ and medical system. Further work is needed to optimize allocation strategies for pediatric candidates.

Organ allocation in pediatric abdominal transplant

Pediatric patients constitute an important group within the general transplant population, given the opportunity to significantly extend their lives with successful transplantation. Children have historically received special consideration under the various abdominal solid organ allocation algorithms, but matching patients with size and weight restrictions with appropriate donors remains an ongoing issue. Here, we describe the historical trends in pediatric organ allocation policies for liver, kidney, intestine, and pancreas transplantation. We also review recent changes to these allocation policies, with particular attention to recent amendments to geographical prioritization, with the dissolution of donor service areas and United Network for Organ Sharing (UNOS) regions and the subsequent creation of acuity circles.

Paediatric deceased donor kidney transplant in Australia: A 30-year review-What have paediatric bonuses achieved and where to from here?

BACKGROUND

In this 30-year national review, we describe trends in DD transplantation for paediatric recipients, assess the impact of paediatric allocation bonuses and identify outstanding areas of need for this population.

METHODS

A retrospective review of all DD kidney only transplants to paediatric recipients (<18 years old) in Australia between 1989 and 2018 was conducted using deidentified extracts from the ANZDATA.

RESULTS

Of the 1011 kidney only transplants performed in paediatric recipients during the study period, 426 (42%) were from deceased donors. Paediatric candidates on the DD waiting list had consistently higher rates of transplantation and shorter time from dialysis initiation to transplantation compared with adult candidates (median 372 vs 832 days in 2018, for example). Donor characteristics remained more favourable for paediatric recipients, despite a decline in the overall quality of the donor pool. The mean number of HLA antigen mismatches for paediatric recipients of DD transplants increased each decade (2.86 [1989-1998], 3.85 [1999-2008], 4.01 [2009-2018]). Both patient and graft survival have improved for paediatric DD transplant recipients in the most recent era (5-year graft and patient survival 85% vs 65% and 99% vs 94%, respectively, for 2009-2018 vs 1999-2008).

CONCLUSIONS

The current DD kidney allocation system in Australia provides rapid access to high-quality organs for paediatric recipients, and early graft loss has decreased significantly in recent years; however, additional targeted interventions to address HLA matching may improve long-term outcomes in this population.

Kidney transplantation in children in KwaZulu-Natal, South Africa

BACKGROUND

CKF is an overwhelming illness, especially in children. Kidney transplantation is considered the definitive management of CKF. It has substantial benefits, including increased patient survival, improved skeletal growth, social adjustment, neuropsychological development, and better quality of life compared to chronic dialysis.

METHODS

This is a retrospective, clinical, observational study in 13 children ≤16 years old who underwent kidney transplantation at IALCH in KwaZulu-Natal, South Africa, from May 2015 to December 2019.

RESULTS

Over 4 years and 7 months, 13 kidney transplants were performed; 7 (53.8%) were males, and 6 (46.2%) were females. Eleven (84.6%) were Black African and 2 (15.4%) Indian children. The mean age ± (SD) of transplantation was 10.1 ± 2.8 years (range 5.8-15.8). Eight (61.5%) children were from a rural setting. The mean ± (SD) duration of follow-up was 29.5 ± 15.9 months. All kidney transplants done were from live related donors; 8 (61.5%) were parents of the recipients. None were pre-emptive transplants. Graft loss occurred in 2 (15.4%) children with 100% patient survival. Two (15.4%) children developed acute rejection.

CONCLUSIONS

The commissioning of transplant services in KwaZulu-Natal, South Africa, has improved access to this modality of treatment, particularly in our Black African patients. The significant limitations we experienced were a shortage of cadaveric donors and resource limitations with no dedicated transplant unit for pediatric patients together with staffing constraints. Enhancing patient and healthcare personal education will hopefully overcome cultural and religious barriers to organ donation.

Use of expanded-criteria donors and > 85 KDPI kidneys for pediatric kidney transplantation in the United States

Pediatric kidney transplant outcomes associated with expanded-criteria donors (ECD) and high Kidney Donor Profile Index (KDPI) kidneys are unknown. We reviewed the Scientific Registry of Transplant Recipients data from 1987-2017 to identify 96 ECD and 92 > 85 KDPI kidney recipients (<18 years). Using propensity scores, we created comparison groups of 375 non-ECD and 357 ≤ 85 KDPI recipients for comparisons with ECD and > 85 KDPI transplants, respectively. We used Cox regression for patient/graft survival and sequential Cox approach for survival benefit of ECD and > 85 KDPI transplantationvs remaining on the waitlist. After adjustment, ECD recipients were at significantly increased risk of graft failure (adjusted hazard ratio [aHR] = 1.6; P = .001) but not of mortality (aHR = 1.33; P = .15) compared with non-ECD recipients. We observed no survival benefit of ECD transplants vs remaining on the waitlist (aHR = 1.05; P = .83). We found no significant difference in graft failure (aHR = 1.27; P = .12) and mortality (aHR = 1.41; P = .13) risks between > 85 KDPI and ≤ 85 KDPI recipients. However, > 85 KDPI transplants were associated with a survival benefit vs remaining on the waitlist (aHR = 0.41; P = .01). ECD transplantation in children is associated with a high graft loss risk and no survival benefit, whereas > 85 KDPI transplantation is associated with a survival benefit for children vs remaining on the waitlist.

Transplantation of a single kidney from pediatric donors less than 10 kg to children with poor access to transplantation: a two-year outcome analysis

Background

Access to kidney transplantation by uremic children is very limited due to the lack of donors in many countries. We sought to explore small pediatric kidney donors as a strategy to provide transplant opportunities for uremic children.

Methods

A total of 56 cases of single pediatric kidney transplantation and 26 cases of en bloc kidney transplantation from pediatric donors with body weight (BW) less than 10 kg were performed in two transplant centers in China and the transplant outcomes were retrospectively analyzed.

Results

The 1-year and 2-year death-censored graft survival in the en bloc kidney transplantation (KTx) group was inferior to that in the single KTx group. Subgroup analysis of the single KTx group found that the 1-year and 2-year death-censored graft survival in the group where the donor BW was between 5 and 10 kg was 97.7 and 90.0%, respectively. However, graft survival was significantly decreased when donor BW was ≤5 kg (p < 0.01), mainly because of the higher rate of thrombosis (p = 0.035). In the single KTx group, the graft length was increased from 6.7 cm at day 7 to 10.5 cm at 36 months posttransplant. The estimated glomerular filtration rate increased up to 24 months posttransplant. Delayed graft function and urethral complications were more common in the group with BW was ≤5 kg.

Conclusions

Our study suggests that single kidney transplantation from donors weighing over 5 kg to pediatric recipients is a feasible option for children with poor access to transplantation.

Temporal Changes in the Impact of HLA Mismatching Among Pediatric Kidney Transplant Recipients

BACKGROUND

Allocation for pediatric deceased-donor kidney transplantation (pDDKT) in the United States now de-emphasizes HLA matching to improve equality in access to transplantation, but other national systems still consider HLA matching due to concerns about graft survival. We hypothesized that the impact of HLA mismatching has decreased over time due to advances including improved immunosuppression.

METHODS

Using Scientific Registry of Transplant Recipient data, we analyzed whether the association between the number of HLA mismatches and outcomes of first-time pDDKTs changed between 2 eras: 1995 to 2004 (N = 2854) and 2005 to 2014 (N = 4643).

RESULTS

Between eras, the median number of mismatches increased from 4 to 5 (P < 0.001). Overall graft failure risk was higher among HLA-mismatched versus HLA-matched transplants (adjusted hazard ratio 1.211.431.69 for 3-6 versus 0-2 mismatches; P < 0.001), and this association was similar pre-2005 and post-2005 (Pinteraction = 0.5). Median panel-reactive antibody change at relisting increased from 79 to 85 (P = 0.01), but the association between number of HLA mismatches and panel-reactive antibody change was similar between eras (Pinteraction = 0.6).

CONCLUSIONS

Our finding that increased HLA mismatching continues to impact graft survival, with 43% higher risk of graft failure, highlights the tradeoff between transplant access equity and outcomes and calls into question the deemphasis on HLA matching in pDDKT allocation in the United States.

Pediatric deceased donor kidney transplant outcomes under the Kidney Allocation System

The Kidney Allocation System (KAS) has resulted in fewer pediatric kidneys being allocated to pediatric deceased donor kidney transplant (pDDKT) recipients. This had prompted concerns that post-pDDKT outcomes may worsen. To study this, we used SRTR data to compare the outcomes of 953 pre-KAS pDDKT (age <18 years) recipients (December 4, 2012-December 3, 2014) with the outcomes of 934 post-KAS pDDKT recipients (December 4, 2014-December 3, 2016). We analyzed mortality and graft loss by using Cox regression, delayed graft function (DGF) by using logistic regression, and length of stay (LOS) by using negative binomial regression. Post-KAS recipients had longer pretransplant dialysis times (median 1.26 vs 1.07 years, P = .02) and were more often cPRA 100% (2.0% vs 0.1%, P = .001). Post-KAS recipients had less graft loss than pre-KAS recipients (hazard ratio [HR]: _0.35 0.54_0.83 , P = .005) but no statistically significant differences in mortality (HR: _0.29 0.72_1.83 , P = .5), DGF (odds ratio: _0.93 1.32_1.93 , P = .2), and LOS (LOS ratio: _0.96 1.06_1.19 , P = .4). After adjusting for donor-recipient characteristics, there were no statistically significant post-KAS differences in mortality (adjusted HR: _0.37 1.04_2.92 , P = .9), DGF (adjusted odds ratio: _0.94 1.41_2.13 , P = .1), or LOS (adjusted LOS ratio: _0.93 1.04_1.16 , P = .5). However, post-KAS pDDKT recipients still had less graft loss (adjusted HR: _0.38 0.59_0.91 , P = .02). KAS has had a mixed effect on short-term posttransplant outcomes for pDDKT recipients, although our results are limited by only 2 years of posttransplant follow-up.

Renal allograft loss due to renal vascular thrombosis in the US pediatric renal transplantation

BACKGROUND

Renal vascular thrombosis (RVT) is a major cause of early allograft loss in the first year following pediatric kidney transplantation. We examined recent trends in allograft loss due to RVT and identified associated risk factors.

METHODS

We identified 14,640 kidney-only transplants performed between 1995 and 2014 with follow-up until June 30, 2016, in 13,758 pediatric patients aged < 19 years from the US Renal Data System. We examined the 1-year incidence of allograft loss due to RVT by year of transplant, and plotted the trend over time. Cox proportional hazards models were used to investigate the relationship between year of transplant as well as recipient, donor, and transplant characteristics with allograft loss due to RVT.

RESULTS

The incidence of allograft loss due to RVT consistently declined among pediatric kidney transplant performed between 1995 and 2014. Among transplants performed between 1995 and 2004, 128/7542 (1.7%) allografts were lost due to RVT compared to 53/7098 (0.8%) among transplants performed between 2005 and 2014; average 1-year cumulative incidence was 1.5% (95% CI, 1.3-1.9%) and 0.6% (95% CI, 0.5-0.8%), respectively. Increased risk for allograft loss due to RVT was associated with en bloc kidney transplantation (HR, 3.42; 95% CI 1.38-8.43) and cold ischemia time ≥ 12 h (HR, 1.78; 95% CI, 1.15-2.76). Interestingly, these risk factors were more prevalent in the latter decade.

CONCLUSIONS

The incidence of allograft loss due to RVT significantly and continuously declined among pediatric kidney transplants performed between 1995 and 2014. The causes for this improvement are unclear in the present analysis.

Long-Term Outcomes of Kidney Transplantation in Children

Kidney transplantation is the preferred treatment for end-stage renal disease (ESRD) in children and confers improved survival, skeletal growth, heath-related quality of life, and neuropsychological development compared with dialysis. Kidney transplantation in children with ESRD results in 10-year patient survival exceeding 90%. Therefore, the long-term management of these patients is focused on maintaining quality of life and minimizing long-term side effects of immunosuppression. Optimal management of pediatric kidney transplant recipients includes preventing rejection and infection, identifying and reducing the cardiovascular and metabolic effects of long-term immunosuppressive therapy, supporting normal growth and development, and managing a smooth transition into adulthood.

Decreasing deceased donor transplant rates among children (≤6 years) under the new kidney allocation system

The Kidney Allocation System (KAS) was implemented in December 2014 with unknown impact on the pediatric waitlist. To understand the effect of KAS on pediatric registrants, deceased donor kidney transplant (DDKT) rate was assessed using interrupted time series analysis and time-to-event analysis. Two allocation eras were defined with an intermediary washout period: Era 1 (01/01/2013-09/01/2014), Era 2 (09/01/2014-03/01/2015), and Era 3(03/01/2015-03/01/2017). When using Cox proportional hazards, there was no significant association between allocation era and DDKT likelihood as compared to Era 1 (Era 3: aHR: 1.07, 95% CI: 0.97-1.18, P = .17). However, this was not consistent across all subgroups. Specifically, while highly sensitized pediatric registrants were consistently less likely to be transplanted than their less sensitized counterparts, this disparity was attenuated in Era 3 (Era 1 aHR: 0.04, 95%CI: 0.01-0.14, P < .001; Era 3 aHR: 0.33, 95% CI: 0.21-0.53, P < .001) whereas the youngest registrants aged 0-6 experienced a 21% decrease in DDKT likelihood in Era 3 as compared to Era 1 (aHR: 0.79, 95% CI: 0.64-0.98, P = .03). Thus, while overall DDKT likelihood remained stable with the introduction of KAS, registrants ≤ 6 years of age were disadvantaged, warranting further study to ensure equitable access to transplantation.

HLA epitope matching in pediatric renal transplantation

Chronic graft loss due to antibody-mediated rejection (AMR) and the difficulty of re-transplanting highly sensitized patients are two of the major long-term challenges in pediatric renal transplantation. Treatments for AMR are often ineffective and desensitization protocols can be a high risk, making prevention a highly appealing strategy. Insights into the structural determinants of humoral alloantigenicity present an exciting opportunity to reassess our current paradigm of tissue matching and potentially preventing these complications. We review the theory behind human leukocyte antigen (HLA) B cell epitopes and the various systems that have been proposed to define them, including eplets. There is a growing body of clinical evidence suggesting that epitope-based tissue matching may be superior to traditional HLA antigen matching at predicting a range of clinical outcomes. However, additional studies are required to better understand the biological relevance of these systems of defining epitopes and their role in pediatric transplantation.

Organ allocation and utilization in pediatric transplantation

Pediatric transplant candidates include heart, lung, liver, pancreas, small intestine, and kidney. The purpose of this article is to review the history and current methods for determining priority of the above-mentioned transplantable organs. The methods used by the authors involved the review of historical and current manuscripts and UNOS policy documents. We summarized the findings in order to create a concise review of the current policies and wait times for transplantation in pediatric transplant patients.

Delayed graft function and its management in children

Delayed graft function (DGF) is commonly defined as the requirement for dialysis within the first 7 days following renal transplantation. The major underlying mechanism is related to ischaemia/reperfusion injury, which includes microvascular inflammation and cell death and apoptosis, and to the regeneration processes. Several clinical factors related to donor, recipient and organ procurement/transplantation procedures may increase the risk of DGF, including donor cardiovascular instability, older donor age, donor creatinine concentration, long cold ischaemia time and marked body mass index of both the donor and recipient. Some of these parameters have been used in specific predictive formulas created to assess the risk of DGF. A variety of other pre-, intra- and post-transplant clinical factors may also increase the risk of DGF, such as potential drug nephrotoxicity, surgical problems and/or hyperimmunization of the recipient. DGF may decrease the long-term graft function, but data on this effect are inconsistent, partially due to the many different types of organ donation. Relevant management strategies may be classified into the classic clinical approach, which has the aim of minimizing the individual risk factors of DGF, and specific pharmacologic strategies, which are designed to prevent or treat ischaemia/reperfusion injury. Both strategies are currently being evaluated in clinical trials.

Longitudinal analysis of living donor kidney transplant rates in pediatric candidates in the United States

Among adults, living donor kidney transplant rates began declining in the United States after 2004 but whether a similar decline is occurring in the pediatric candidates has not been well studied. Share 35, a change in allocation rules implemented in October of 2005, may also have influenced rates of living donation. We sought to determine whether a decline in rates was occurring in pediatric candidates and whether the Share 35 program was the cause of the decline. All children listed for a kidney transplant or transplanted with a living donor without listing between 1996 and 2011 were identified in the United States (N=14 911) of which 6046 had received a living donor transplant during follow-up. Kaplan-Meier analysis showed a decline in living donor rates in candidates listed after 2001. Logistic regression analysis for living donor kidney transplantation confirmed the timing of the drop but also showed that changes in candidate demographics and center listing practices were impacting rates. A large drop in parental donation was the main cause for the drop. The rate of living donor transplant among pediatric candidates declined after 2001 predating by 4 years the implementation of Share 35, suggesting that factors other than changes in allocation rules are responsible for the decline.

Balancing competing needs in kidney transplantation: does an allocation system prioritizing children affect the renal transplant function?

Children often merit priority in access to deceased donor kidneys by organ-sharing organizations. We report the impact of the new Swiss Organ Allocation System (SOAS) introduced in 2007, offering all kidney allografts from deceased donors <60 years preferentially to children. The retrospective cohort study included all paediatric transplant patients (<20 years of age) before (n = 19) and after (n = 32) the new SOAS (from 2001 to 2014). Estimated glomerular filtration rate (eGFR), urine protein-to-creatinine ratio (UPC), need for antihypertensive medication, waiting times to kidney transplantation (KTX), number of pre-emptive transplantations and rejections, and the proportion of living donor transplants were considered as outcome parameters. Patients after the new SOAS had significantly better eGFRs 2 years after KTX (Mean Difference, MD = 25.7 ml/min/1.73 m² , P = 0.025), lower UPC ratios (Median Difference, MeD = -14.5 g/mol, P = 0.004), decreased waiting times to KTX (MeD = -97 days, P = 0.021) and a higher proportion of pre-emptive transplantations (Odds Ratio = 9.4, 95% CI = 1.1-80.3, P = 0.018), while the need for antihypertensive medication, number of rejections and living donor transplantations remained stable. The new SOAS is associated with improved short-term clinical outcomes and more rapid access to KTX. Despite lacking long-term research, the study results should encourage other policy makers to adopt the SOAS approach.

Application of an epitope-based allocation system in pediatric kidney transplantation

Donor-recipient HLA mismatch remains a leading cause for sensitization and graft loss in kidney transplantation. HLA compatibility at an epitope level is emerging as an improved method of matching compared with current HLA antigen allocation. A novel epitope-based allocation approach to prospectively exclude donors with high-level mismatches was implemented for pediatric KTRs on the DD waiting list. Nineteen consecutive transplants were followed for 12 months, including eight DD KTRs listed with eplet exclusions, as well as three DD KTRs and eight LD KTRs without exclusions. KTRs with eplet exclusions had estimated GFR of 78.5 mL/min/1.73 m² , no episodes of rejection, and time to transplant 6.55 months. HLA-A, HLA-B, HLA-DR antigen mismatches were similar between all groups. KTRs with exclusions had significantly lower class II eplet mismatches (20.4) than the contemporary DD KTRs without exclusions (63.7) and DD KTRs transplanted in the preceding decade (46.9). dnDSAs were identified in two of eight DD KTRs with exclusions, two of three DD KTRs without exclusions and five of eight LD KTRs. Epitope-based allocation achieved timely access to transplantation, low class II eplet mismatches, and low rates of dnDSAs in the first year. This strategy requires longer follow-up and larger numbers, but has the potential to reduce anti-HLA sensitization and improve both graft survival and opportunities for future retransplantation.

Preemptive kidney transplantation is associated with survival benefits among pediatric patients with end-stage renal disease

Kidney transplantation is the preferred treatment for pediatric end-stage renal disease (ESRD). Preemptive transplantation avoids the increased morbidity and mortality of dialysis. Yet, previous studies have not demonstrated significant graft or patient survival benefits for children undergoing transplantation preemptively versus nonpreemptively. These previous studies were limited by small samples sizes and low rates of adverse events. Here we compared graft failure and mortality rates using Kaplan-Meier methods and Cox regression among a large national cohort of children with ESRD undergoing preemptive versus nonpreemptive kidney transplantation between 2000 and 2012. Among 7527 pediatric kidney transplant recipients in the United States Renal Data System, 1668 underwent preemptive transplantation. Over a median 4.8 years follow-up, 1314 experienced graft failure, and over a median 5.2 years of follow-up, 334 died. Dialysis exposure versus preemptive transplantation conferred a higher risk of graft failure (hazard ratio 1.32; 95% confidence interval: 1.10-1.56) and a higher risk of death (hazard ratio 1.69; 95% confidence interval: 1.22-2.33) in multivariable analysis. Compared with children undergoing preemptive transplantation, children on dialysis for >1 year had a 52% higher risk of graft failure and those on dialysis >18 months had an 89% higher risk of death, regardless of donor source. Thus, preemptive transplantation is associated with substantial benefits in allograft and patient survival among children with ESRD, particularly when compared with children who receive dialysis for >1 year. These findings support policies to promote early access to transplantation and avoidance of dialysis for children with ESRD whenever feasible.

Pediatric Deceased Donation-A Report of the Transplantation Society Meeting in Geneva

The Ethics Committee of The Transplantation Society convened a meeting on pediatric deceased donation of organs in Geneva, Switzerland, on March 21 to 22, 2014. Thirty-four participants from Africa, Asia, the Middle East, Oceania, Europe, and North and South America explored the practical and ethical issues pertaining to pediatric deceased donation and developed recommendations for policy and practice. Their expertise was inclusive of pediatric intensive care, internal medicine, and surgery, nursing, ethics, organ donation and procurement, psychology, law, and sociology. The report of the meeting advocates the routine provision of opportunities for deceased donation by pediatric patients and conveys an international call for the development of evidence-based resources needed to inform provision of best practice care in deceased donation for neonates and children.

Pediatric deceased donor renal transplantation: An approach to decision making I. Pediatric kidney allocation in the USA: The old and the new

Renal transplantation is the treatment of choice for children with end-stage renal disease. More than 50% of children receive a deceased donor renal transplant. Marked disparity between the number of children on the renal transplant wait list and the supply has prompted numerous advances to increase supply as well as maximize the utility of donor organs. Allocation of deceased donor kidneys is based on several criteria. The organ allocation system policy is continually evaluated and changed incrementally to optimize allocation. We, in the United States, are in the process of transitioning into a new kidney allocation system to enhance post-transplant survival benefit, increase utilization of donated kidneys, and increase transplant access for biologically disadvantaged candidates. This review will provide a brief overview of the organ sharing system in the United States, compare the "old" and the "new" allocation system, and discuss the considerations for the pediatric nephrologist while accepting a deceased donor kidney for a particular pediatric patient.

Australian deceased donor kidney allocation protocols: Transplant waiting and graft quality for children and adolescents

DD kidney allocation protocols may influence timing of transplantation and graft quality for pediatric recipients. This study aimed to evaluate the effects of these protocols, including pediatric priority, on waiting time on dialysis, transplant type, donor age, and HLA matching according to state of transplant in Australia. De-identified information on patients <15 yr of age who commenced RRT in NSW, Qld, and Victoria from 2002 to 2011 was retrieved from the ANZDATA. Transplant type, donor age, and HLA mismatching were compared between states, with competing risk regression used to examine the time to transplant. There were significant differences in waiting time to DD transplantation between the three states. Children in NSW and Qld waited a median of 14 and 11 months vs. 21 months in Victoria. The ratio of LD to DD transplants was lower in NSW and Qld. Differences correlated with DD pediatric priority in NSW and Qld. DDs in NSW were older than in the other states. HLA matching did not differ. DD kidney allocation protocols with pediatric priority in Australian states were associated with shorter waiting times and increased DD proportion.

Living Donor Kidney Transplantation: Overcoming Disparities in Live Kidney Donation in the US--Recommendations from a Consensus Conference

Despite its superior outcomes relative to chronic dialysis and deceased donor kidney transplantation, live donor kidney transplantation (LDKT) is less likely to occur in minorities, older adults, and poor patients than in those who are white, younger, and have higher household income. In addition, there is considerable geographic variability in LDKT rates. Concomitantly, in recent years, the rate of living kidney donation (LKD) has stopped increasing and is declining, after decades of consistent growth. Particularly noteworthy is the decline in LKD among black, younger, male, and lower-income adults. The Live Donor Community of Practice within the American Society of Transplantation, with financial support from 10 other organizations, held a Consensus Conference on Best Practices in Live Kidney Donation in June 2014. The purpose of this meeting was to identify LKD best practices and knowledge gaps that might influence LDKT, with a focus on patient and donor education, evaluation efficiencies, disparities, and systemic barriers to LKD. In this article, we discuss trends in LDKT/LKD and emerging novel strategies for attenuating disparities, and we offer specific recommendations for future clinical practice, education, research, and policy from the Consensus Conference Workgroup focused on disparities.

Vascular access for chronic hemodialysis in children: arteriovenous fistula or central venous catheter?

BACKGROUND

The choice of vascular access (VA) for hemodialysis (HD) in end-stage renal disease (ESRD) is arteriovenous fistula (AVF) or central venous catheter (CVC). Whereas clinical practice guidelines suggest AVF to preserve the vascular bed, pediatric nephrologists tend to favor CVC for shorter-term dialysis. Our objective was to determine whether pediatric priority allocation policies for deceased-donor kidneys affect VA planning.

METHODS

Pediatric priority for deceased-donor kidneys was instituted in Quebec in 2004. We retrospectively compared clinical practice on AVF, CVC, wait time on transplant list, HD duration in pre-policy (group A) and post-policy (group B) from 1997-2011.

RESULTS

We identified 78 patients with a median age of 14.7 years (range, 0.7-20.5 years) and weight of 46 kg (12.5-95 kg); AVF decreased from 76 % in group A to 41 % in group B (p = 0.002). Wait times on transplant list were significantly reduced: median 413.5 days (range, 2-1,910 days) in group A vs. 89 days (range, 18-692 days) in group B (p = 0.003). Time on HD for deceased-donor recipients was shorter: 705 (range, 51-1,965 days) group A vs. 349.5 days (range, 158-1,060 days) group B (p = 0.01).

CONCLUSIONS

This is the first study to document VA changes related to pediatric priority allocation policy. Our fistula-first center saw a shift toward CVC-first.

Disparities, race/ethnicity and access to pediatric kidney transplantation

PURPOSE OF REVIEW

Kidney transplantation remains the optimal treatment for children with end-stage renal disease; yet, in the United States, profound differences in access to transplant persist, with black children experiencing significantly reduced access to transplant compared with white children. The reasons for these disparities remain poorly understood. Several recent studies provide new insights into the interplay of socioeconomic status, racial/ethnic disparities and access to pediatric kidney transplantation.

RECENT FINDINGS

New evidence suggests that disparities are more pronounced in access to living vs. deceased donors. National allocation policies have mitigated racial differences in pediatric deceased donor kidney transplant (DDKT) access after waitlisting. However, disparities in access to DDKT are stark for minority emerging adults, who lose pediatric priority allocation. Although absence of health insurance poses an important barrier to transplant, even after adjustment for insurance status and neighborhood poverty, disparities persist. Differential access to care and unjust social structures are posited as important modifiable barriers to achieving equity in pediatric transplant access.

SUMMARY

Future approaches to overcome disparities in pediatric kidney transplant access must focus on the continuum of the transplant process, including equitable health care access. Public health advocacy efforts to promote national policies that address disparate multilevel socioeconomic factors are essential.

The consequences of chronic kidney disease mislabeling in living kidney donors

Despite numerous studies that substantiate its long-term safety, barriers to kidney donation persist. These include issues of insurability after donation and its consequent financial and emotional burdens. We present 2 cases in which mislabeling of kidney donors as having chronic kidney disease shortly after kidney donation adversely affected their insurability. A concerted effort should be made to affect public policy such that insurability and the psychosocial well-being of living donors are protected.

National trends over 25 years in pediatric kidney transplant outcomes

OBJECTIVE

To investigate changes in pediatric kidney transplant outcomes over time and potential variations in these changes between the early and late posttransplant periods and across subgroups based on recipient, donor, and transplant characteristics.

METHODS

Using multiple logistic regression and multivariable Cox models, graft and patient outcomes were analyzed in 17,446 pediatric kidney-only transplants performed in the United States between 1987 and 2012.

RESULTS

Ten-year patient and graft survival rates were 90.5% and 60.2%, respectively, after transplantation in 2001, compared with 77.6% and 46.8% after transplantation in 1987. Primary nonfunction and delayed graft function occurred in 3.3% and 5.3%, respectively, of transplants performed in 2011, compared with 15.4% and 19.7% of those performed in 1987. Adjusted for recipient, donor, and transplant characteristics, these improvements corresponded to a 5% decreased hazard of graft loss, 5% decreased hazard of death, 10% decreased odds of primary nonfunction, and 5% decreased odds of delayed graft function with each more recent year of transplantation. Graft survival improvements were lower in adolescent and female recipients, those receiving pretransplant dialysis, and those with focal segmental glomerulosclerosis. Patient survival improvements were higher in those with elevated peak panel reactive antibody. Both patient and graft survival improvements were most pronounced in the first posttransplant year.

CONCLUSIONS

Outcomes after pediatric kidney transplantation have improved dramatically over time for all recipient subgroups, especially for highly sensitized recipients. Most improvement in graft and patient survival has come in the first year after transplantation, highlighting the need for continued progress in long-term outcomes.

Impact of HLA mismatch at first kidney transplant on lifetime with graft function in young recipients

As HLA matching has been progressively de-emphasized in the American deceased donor (DD) kidney allocation algorithm, concerns have been raised that poor matching at first transplant may lead to greater sensitization and more difficulty finding an acceptable donor for a second transplant should the first transplant fail. We compared proportion of total observed lifetime with graft function after first transplant, and waiting times for a second transplant between individuals with different levels of HLA mismatch (MM) at first transplant. We studied patients recorded in the United States Renal Data System (1988-2009) who received a first DD transplant at age ≤21 years (n = 8433), and the subgroup who were listed for a second DD transplant following first graft failure (n = 2498). Compared with recipients of 2-3 MM first grafts, 4-6 MM graft recipients spent 12% less of their time and 0-1 MM recipients 15% more time with a functioning graft after the first transplant (both p < 0.0001); 4-6 MM recipients were significantly less likely (hazard ratio [HR] 0.87 [95% confidence interval 0.76, 0.98]; p = 0.03), and 0-1 MM recipients more likely (HR 1.26 [0.99, 1.60]; p = 0.06) to receive a second transplant after listing. The benefits of better HLA matching at first transplant on lifetime with graft function are significant, but relatively small.

Geographic determinants of access to pediatric deceased donor kidney transplantation

Children receive priority in the allocation of deceased donor kidneys for transplantation in the United States, but because allocation begins locally, geographic differences in population and organ supply may enable variation in pediatric access to transplantation. We assembled a cohort of 3764 individual listings for pediatric kidney transplantation in 2005-2010. For each donor service area, we assigned a category of short (<180 days), medium (181-270 days), or long (>270 days) median waiting time and calculated the ratio of pediatric-quality kidneys to pediatric candidates and the percentage of these kidneys locally diverted to adults. We used multivariable Cox regression analyses to examine the association between donor service area characteristics and time to deceased donor kidney transplantation. The Kaplan-Meier estimate of median waiting time to transplantation was 284 days (95% confidence interval, 263 to 300 days) and varied from 14 to 1313 days across donor service areas. Overall, 29% of pediatric-quality kidneys were locally diverted to adults. Compared with areas with short waiting times, areas with long waiting times had a lower ratio of pediatric-quality kidneys to candidates (3.1 versus 5.9; P<0.001) and more diversions to adults (31% versus 27%; P<0.001). In multivariable regression, a lower kidney to candidate ratio remained associated with longer waiting time (hazard ratio, 0.56 for areas with <2:1 versus reference areas with ≥5:1 kidneys/candidates; P<0.01). Large geographic variation in waiting time for pediatric deceased donor kidney transplantation exists and is highly associated with local supply and demand factors. Future organ allocation policy should address this geographic inequity.

The decline in living kidney donation in the United States: random variation or cause for concern?

The annual number of living kidney donors in the United States peaked at 6647 in 2004. The preceding decade saw a 120% increase in living kidney donation. However, since 2004, living kidney donation has declined in all but 1 year, resulting in a 13% decline in the annual number of living kidney donors from 2004 to 2011. The proportional decline in living kidney donation has been more pronounced among men, blacks, younger adults, siblings, and parents. In this article, we explore several possible explanations for the decline in living kidney donation, including an increase in medical unsuitability, an aging transplant patient population, financial disincentives, public policies, and shifting practice patterns, among others. We conclude that the decline in living donation is not merely reflective of random variation but one that warrants action by the transplant centers, the broader transplant community, and the state and national governments.

Order of donor type in pediatric kidney transplant recipients requiring retransplantation

BACKGROUND

Living-donor kidney transplantation (KT) is encouraged for children with end-stage renal disease due to superior long-term graft survival compared with deceased-donor KT. Despite this, there has been a steady decrease in the use of living-donor KT for pediatric recipients. Due to their young age at transplantation, most pediatric recipients eventually require retransplantation, and the optimal order of donor type is not clear.

METHODS

Using the Scientific Registry of Transplant Recipients, we analyzed first and second graft survival among 14,799 pediatric (<18 years old) recipients undergoing KT between 1987 and 2010.

RESULTS

Living-donor grafts had longer survival compared with deceased-donor grafts, similarly among both first (adjusted hazard ratio [aHR], 0.78; 95% confidence interval [CI], 0.73-0.84; P<0.001) and second (aHR, 0.74; 95% CI, 0.64-0.84; P<0.001) transplants. Living-donor second grafts had longer survival compared with deceased-donor second grafts, similarly after living-donor (aHR, 0.68; 95% CI, 0.56-0.83; P<0.001) and deceased-donor (aHR, 0.77; 95% CI, 0.63-0.95; P=0.02) first transplants. Cumulative graft life of two transplants was similar regardless of the order of deceased-donor and living-donor transplantation.

CONCLUSIONS

Deceased-donor KT in pediatric recipients followed by living-donor retransplantation does not negatively impact the living-donor graft survival advantage and provides similar cumulative graft life compared with living-donor KT followed by deceased-donor retransplantation. Clinical decision-making for pediatric patients with healthy, willing living donors should consider these findings in addition to the risk of sensitization, aging of the living donor, and deceased-donor waiting times.

Disparities in policies, practices and rates of pediatric kidney transplantation in Europe

We aimed to provide an overview of kidney allocation policies related to children and pediatric kidney transplantation (KTx) practices and rates in Europe, and to study factors associated with KTx rates. A survey was distributed among renal registry representatives in 38 European countries. Additional data were obtained from the ESPN/ERA-EDTA and ERA-EDTA registries. Thirty-two countries (84%) responded. The median incidence rate of pediatric KTx was 5.7 (range 0-13.5) per million children (pmc). A median proportion of 17% (interquartile range 2-29) of KTx was performed preemptively, while the median proportion of living donor KTx was 43% (interquartile range 10-52). The median percentage of children on renal replacement therapy (RRT) with a functioning graft was 62%. The level of pediatric prioritization was associated with a decreased waiting time for deceased donor KTx, an increased pediatric KTx rate, and a lower proportion of living donor KTx. The rates of pediatric KTx, distribution of donor source and time on waiting list vary considerably between European countries. The lack of harmonization in kidney allocation to children raises medical and ethical issues. Harmonization of pediatric allocation policies should be prioritized.

Living unrelated renal transplantation: a good match for the pediatric candidate?

BACKGROUND/PURPOSE

Living donor kidney transplantation is encouraged for children with end-stage renal disease given the superior survival of living donor grafts, but pediatric candidates are also given preference for kidneys from younger deceased donors.

METHODS

Death-censored graft survival of pediatric kidney-only transplants performed in the U.S. between 1987-2012 was compared across living related (LRRT) (n=7741), living unrelated (LURT) (n=618), and deceased donor renal transplants (DDRT) (n=8945) using Kaplan-Meier analysis, multivariable Cox proportional hazards models, and matched controls analysis.

RESULTS

As expected, HLA mismatch was greater among LURT compared to LRRT (p<0.001). Unadjusted graft survival was lower, particularly long-term, for LURT compared to LRRT (p=0.009). However, LURT graft survival was still superior to DDRT graft survival, even when compared only to deceased donors under age 35 (p=0.002). The difference in graft survival between LURT and LRRT was not seen when adjusting for HLA mismatch, year of transplantation, and donor and recipient characteristics using a Cox model (aHR=1.04, 95% CI: 0.87-1.24, p=0.7) or matched controls (HR=1.02, 95% CI: 0.82-1.27, p=0.9).

CONCLUSION

Survival of LURT grafts is superior to grafts from younger deceased donors and equivalent to LRRT grafts when adjusting for other factors, most notably differences in HLA mismatch.

Pediatric kidney transplant practice patterns and outcome benchmarks, 1987-2010: a report of the North American Pediatric Renal Trials and Collaborative Studies

The NAPRTCS transplant registry has collected clinical information on children undergoing kidney transplantation since 1987 and now includes information on 11 603 kidney transplants in 10 632 patients. Since the first data analysis in 1989, NAPRTCS reports have documented marked improvements in outcome after kidney transplantation in addition to identifying factors associated with both favorable and poor outcomes. Patient demographics have changed over the course of the registry with a decrease in the percentage of white recipients from a high of 72% in 1987 to less than 43% in 2007. The percentage of living donors decreased to its lowest point in 2007 at 37%. Acute rejection rates continue to decline with improvements in short- and long-term graft survival. Recently, NAPRTCS data have been used as a source of benchmark data for pediatric kidney transplant centers.

Use of nurse practitioners in pediatric kidney transplant: a model for providing comprehensive care to children and families

It is well documented that kidney transplantation is the treatment of choice for children with end-stage renal disease. Pediatric kidney transplant patients are a complex population because of their need for lifelong immunosuppression, potential for delayed growth and development, and increased risk of heart disease and cancer. Although many large pediatric kidney transplant programs use nurse practitioners, the role of the nurse practitioner is still emerging in relation to the transplant coordinator role. This article describes the practice of pediatric nurse practitioners caring for children who require a kidney transplant and why nurse practitioners are ideal for providing comprehensive care to this population. Transplant programs are regulated by the United Network for Organ Sharing and the Centers for Medicare and Medicaid Services. Both organizations require transplant programs to designate a transplant coordinator with the primary responsibility of coordinating clinical aspects of transplant care. Incorporating transplant coordinator activities into the role of the pediatric nurse practitioner is discussed as a model for providing care throughout the process of kidney transplantation. Transplant pediatric nurse practitioners are in a unique position to expand the care for pediatric kidney transplant patients by assuming the role of clinician, educator, administrator, and coordinator.

Racial disparities in access to pediatric kidney transplantation since share 35

Share 35 was enacted in 2005 to shorten transplant wait times and provide high-quality donors to children with ESRD. To investigate the possible effect of this policy on racial disparities in access to pediatric transplantation, we analyzed data from the US Renal Data System before and after Share 35. Among 4766 pediatric patients with incident ESRD, the probability of receiving a deceased-donor kidney transplant increased 46% after Share 35, with Hispanics experiencing the greatest improvements (increases of 81% for Hispanics, 45% for blacks, and 37% for whites). On average, patients received a deceased-donor kidney transplant earlier after Share 35, but this finding varied by race: 63 days earlier for whites, 90 days earlier for blacks, and 201 days earlier for Hispanics. Furthermore, a shift from living- to deceased-donor sources occurred with Share 35 for all races, with a 25% reduction in living donors for whites compared with 48% and 46% reductions for Hispanics and blacks, respectively. In summary, Share 35 seems to have attenuated racial disparities in the time to and probability of children receiving a deceased-donor kidney transplant. These changes coincided with changes in the rates of living-donor sources, which vary by race. Future studies should explore how these changes may impact racial differences in long-term graft outcomes.

Inferior allograft outcomes in adolescent recipients of renal transplants from ideal deceased donors

OBJECTIVE

To measure the impact of the Share-35 policy on the allocation of ideal deceased donor kidneys and to examine the impact of age on outcomes after kidney transplantation using ideal donor kidneys.

BACKGROUND

In the United States, through Share-35, transplant candidates aged 18 years or younger receive priority for the highest-quality deceased donor kidneys. Adolescent (15-18 years) kidney transplant recipients (KTRs), however, may be more susceptible to allograft loss due to elevated rates of acute rejection and a possible increased risk of primary renal disease recurrence.

METHODS

We used registry data to perform a retrospective cohort study of 39,136 KTRs from January 1, 1994, to December 31, 2008. Ideal donors were defined as 2 to 34 years old with creatinine <1.5 mg/dL and absence of hypertension, diabetes, and hepatitis C.

RESULTS

After Share-35, the percentage of ideal donor kidneys allocated to pediatric recipients increased from 7% to 16%. In multivariable Cox regression, compared with adolescent KTRs, all age strata except recipients older than 70 years had a lower risk of allograft failure (P < 0.01 for each comparison); results were similar after excluding KTRs with diseases at high risk of recurrence. Adolescent recipients had higher mortality rates than KTRs younger than 14 years, similar mortality compared with that of KTRs older than 18 and younger than 40 years, and lower mortality than KTRs older than 40 years.

CONCLUSIONS

The allocation of "ideal donors" to adolescent recipients may not maximize graft utility. Reevaluation of pediatric allocation priority may offer opportunities to optimize ideal renal allograft survival.

Use of Nurse Practitioners in Pediatric Kidney Transplant: A Model for Providing Comprehensive Care to Children and Families

It is well documented that kidney transplantation is the treatment of choice for children with end-stage renal disease. Pediatric kidney transplant patients are a complex population because of their need for lifelong immunosuppression, potential for delayed growth and development, and increased risk of heart disease and cancer. Although many large pediatric kidney transplant programs use nurse practitioners, the role of the nurse practitioner is still emerging in relation to the transplant coordinator role. This article describes the practice of pediatric nurse practitioners caring for children who require a kidney transplant and why nurse practitioners are ideal for providing comprehensive care to this population. Transplant programs are regulated by the United Network for Organ Sharing and the Centers for Medicare and Medicaid Services. Both organizations require transplant programs to designate a transplant coordinator with the primary responsibility of coordinating clinical aspects of transplant care. Incorporating transplant coordinator activities into the role of the pediatric nurse practitioner is discussed as a model for providing care throughout the process of kidney transplantation. Transplant pediatric nurse practitioners are in a unique position to expand the care for pediatric kidney transplant patients by assuming the role of clinician, educator, administrator, and coordinator.