Risk Factors for Short- and Long-term Survival of Primary Cadaveric Renal Allografts in Pediatric Recipients: A UNOS Analysis

The impact of multiple donor renal arteries on perioperative complications and allograft survival in paediatric renal transplantation

BACKGROUND

The impact of using allografts with multiple renal arteries in paediatric kidney transplantation has not been clearly established. The aim of this study was to determine whether kidney grafts with multiple arteries pose any adverse effects upon perioperative surgical outcomes, and graft survival up to 12 months post-transplant.

OBJECTIVE

The objective of this study was to perform a comparative analysis of a minimum of 12-month graft survival and transplant renal function in paediatric renal transplant recipients receiving single versus multiple donor arteries, and to assess perioperative and early post-operative surgical outcomes.

STUDY DESIGN

A retrospective divisional chart review of 379 transplants performed (2000-2018), of which 90 (23.7%) contained multiple donor arteries. The number of arteries of the graft, donor type, vascular reconstruction technique, occurrence of urological and vascular complications, estimated GFR and graft survival up to 12 months post-transplantation, graft loss and mortality were analysed. Comparisons in baseline characteristics and outcome measures were made between both groups.

RESULTS

No significant differences were found in age (p = 0.42), BMI (p = 0.39), estimated intraoperative blood loss (p = 0.14), overall (p = 0.63) or warm ischaemic time (p = 0.37). 51.3% patients with multiple donor arteries underwent an ex vivo reconstruction. There were no differences in the site of arterial anastomosis (aorta, external iliac, internal iliac), or anastomotic type (end-side; end-end). Whilst there was a significantly higher post-operative lymphocoele rate in the multiple vessel cohort (p = 0.024), there was no increase in post-transplant urine leaks, rejection episodes, graft loss (1.1% multiple vs 2.1% single), perioperative complications (p = 0.68), or estimated GFR at 1 month (p = 0.9) or at 1 year (p = 0.67).

DISCUSSION

We demonstrated in this study that there was no significant difference in postoperative complications up to 3 months, eGFR and renal function up to 1 year, and graft survival up to 4 years post transplantation irrespective of allograft type or reconstruction technique. There was however, a higher rate of lymphocoeles in the multiple artery cohort. The results seen here broadly mirror trends seen in adult studies, however, there is little data available from paediatric series.

CONCLUSION

Our study demonstrates that multiple renal artery allografts - previously been considered to carry a high complication risk - can be safely used for paediatric renal transplantation with equivalent perioperative complications and graft outcomes to single artery allografts.

Yield and utility of surveillance kidney biopsies in pediatric kidney transplant recipients at various time points post-transplant

BACKGROUND

Due to a lack of consensus on SB for pediatric kidney transplant recipients, we evaluated the yield and clinical utility of SB findings at various time points post-transplant.

METHODS

Patients transplanted at a single institution between 2014 and 2020 with at least one SB at 1.5, 3, 6, 12, and 24 months post-transplant were included. Additional biopsies were done for indication (IB). TCMR was classified by Banff criteria (score ≥i1t1).

RESULTS

Forty-seven patients had 142 biopsies (SB = 113, IB = 29); 19 (40.4%) of whom experienced at least one TCMR episode in the first-year post-transplant. The greatest SB yield of any pathologic abnormality was at 6 months (57.1%; P < .001). Six months also had the highest yield for TCMR (42.9%), compared with 3.3%, 20.8%, 15.0%, and 9.1% at 1.5, 3, 12 months, and 24 months, respectively (P = .003). SB instigated intensification of immunosuppression (28.3% cases), reduction of immunosuppression (2.7% cases), and other non-immunosuppressant changes (1.8% cases). The 6-month SB led to the greatest number of changes in management (53.6%), compared with 1.5, 3, 12, and 24 months (13.3, 20.8, 25.0, and 36.4%, respectively; P = .012). There were no major biopsy-related complications.

CONCLUSIONS

SBs identify an important burden of subclinical rejection and other pathology leading to changes in clinical management. The greatest yield was at 6 months, whereas the least utility was at the 1.5 months. Selection of SB timing may be tailored such that the optimal yield is balanced against the procedural risk.

Acute rejection in pediatric renal transplantation: Retrospective study of epidemiology, risk factors, and impact on renal function

AR is a major relevant and challenging topic in pediatric kidney transplantation. Our objective was to evaluate cumulative incidence of AR in pediatric kidney transplant patient, risk factors for this outcome, and impact on allograft function and survival. A retrospective cohort including pediatric patients that underwent kidney transplantation between 2011 and 2015 was designed. Risk factors for AR were tested by competing risk analysis. To estimate its impact, graft survival and difference in GFR were evaluated. Two hundred thirty patients were included. As a whole, the incidence of AR episodes was 0.16 (95% CI = 0.12-0.20) per person-year of follow-up. And cumulative incidence of AR was 23% in 1 year and 39% in 5 years. Risk factors for AR were number of MM (SHR 1.36 CI 1.14-1.63 P = .001); ISS with CSA, PRED, and AZA (SHR 2.22 CI 1.14-4.33 P = .018); DGF (SHR 2.49 CI 1.57-3.93 P < .001); CMV infection (SHR 5.52 CI 2.27-11.0 P < .001); and poor adherence (SHR 2.28 CI 1.70-4.66 P < .001). Death-censored graft survival in 1 and 5 years was 92.5% and 72.1%. Risk factors for graft loss were number of MM (HR 1.51 CI 1.07-2.13 P = .01), >12 years (HR 2.66 CI 1.07-6.59 P = .03), and PRA 1%-50% (HR 2.67 CI 1.24-5.73 P = .01). Although occurrence of AR did not influence 5-year graft survival, it negatively impacted GFR. AR was frequent in patients assessed and associated with number of MM, ISS regimen, DGF, CMV infection, and poor adherence, and had deleterious effect on GFR.

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.

The Risk of Failure With HLA Mismatch and Recipient Age in First Pediatric (<18 years) Kidney Transplants

BACKGROUND

Even in the modern era of kidney transplantation with improved surgical techniques, immunosuppression, and clinical care, HLA matching has been shown to be important in allograft survival in adults who receive an organ from either a deceased or living donor. We now explore the impact of genetic matching in pediatric first-kidney transplants.

METHODS

Using the United Network for Organ Sharing data, we identified 18 602 first pediatric (<18 years) kidney transplants between October 1, 1987, and December 31, 2016. Recipients were classified by number of HLA mismatches and donor origin. Cox proportional hazard analyses, adjusting for recipient and donor transplant covariates, were performed to study the impact of HLA on kidney allograft survival.

RESULTS

For the fully adjusted Cox model there was a 30% increase in the hazard of allograft failure for 1 HLA mismatch, when compared with 0 mismatched recipients, and a 92% increase in risk for 6 mismatches. Although pediatric allografts from living donors survive as long or longer than those from deceased persons, they have a higher hazard of failure as a function of HLA mismatch. Kidney allografts from deceased donors HLA mismatched 0 to 3 were found to survive as long as organs from living donors HLA mismatched 4 to 6. In the full Cox model, there was a strong, linear effect on the hazard of allograft failure with quartile of age such that the youngest patients at age of transplant had the longest surviving grafts.

CONCLUSIONS

HLA plays an important role in the survival of first pediatric kidney transplants. The better the match, and the earlier the transplant is performed in the child's life, the lower is the risk that the organ will fail.

Impact of the kidney allocation system on young pediatric recipients

The kidney allocation system (KAS) altered pediatric candidate prioritization. We determined KAS's impact on pediatric kidney recipients by examining delayed graft function (DGF) rates from 2010 to 2016. A propensity score-matched pediatric recipients pre- and post-KAS. A semiparametric decomposition analysis estimated the contributions of KAS-related changes in donor characteristics and dialysis time on DGF rate. The unadjusted odds of DGF were 69% higher post-KAS for young (<10 years at listing) recipients (N = 1153, P = .02) but were not significantly increased for older pediatric (10-17 years at listing) recipients (N = 2624, P = .48). Post-KAS, young recipients received significantly fewer pediatric (<18 years) donor kidneys (21% vs 32%, P < .01) and had longer median pretransplant dialysis time (603 vs 435 days, P < .01). After propensity score matching, post-KAS status increased the odds of DGF in young recipients 71% (OR 1.71, 95% CI 1.01-2.46). In decomposition analysis, 24% of the higher DGF rate post-KAS was attributable to donor characteristics and 19% to increased recipient dialysis time. In a confirmatory survival analysis, DGF was associated with a 2.2 times higher risk of graft failure (aHR2.28, 95% CI 1.46-3.54). In conclusion, KAS may lead to worse graft survival outcomes in children. Allocation changes should be considered.

Age-Dependent Risk of Graft Failure in Young Kidney Transplant Recipients

BACKGROUND

The risk of graft failure in young kidney transplant recipients has been found to increase during adolescence and early adulthood. However, this question has not been addressed outside the United States so far. Our objective was to investigate whether the hazard of graft failure also increases during this age period in France irrespective of age at transplantation.

METHODS

Data of all first kidney transplantation performed before 30 years of age between 1993 and 2012 were extracted from the French kidney transplant database. The hazard of graft failure was estimated at each current age using a 2-stage modelling approach that accounted for both age at transplantation and time since transplantation. Hazard ratios comparing the risk of graft failure during adolescence or early adulthood to other periods were estimated from time-dependent Cox models.

RESULTS

A total of 5983 renal transplant recipients were included. The risk of graft failure was found to increase around the age of 13 years until the age of 21 years, and decrease thereafter. Results from the Cox model indicated that the hazard of graft failure during the age period 13 to 23 years was almost twice as high as than during the age period 0 to 12 years, and 25% higher than after 23 years.

CONCLUSIONS

Among first kidney transplant recipients younger than 30 years in France, those currently in adolescence or early adulthood have the highest risk of graft failure.

Effects of acute rejection vs new-onset diabetes after transplant on transplant outcomes in pediatric kidney recipients: analysis of the Organ Procurement and Transplant Network/United Network for Organ Sharing (OPTN/UNOS) database

Improving long-term transplant and patient survival is still an ongoing challenge in kidney transplant medicine. Our objective was to identify the subsequent risks of new-onset diabetes after transplant (NODAT) and acute rejection (AR) in the first year post-transplant in predicting mortality and transplant failure. A total of 4687 patients without preexisting diabetes (age 2-20 years, 2004-2010) surviving with a functioning transplant for longer than 1 year with at least one follow-up report were identified from the OPTN/UNOS database as of September 2014. Study population was stratified into four mutually exclusive groups: Group 1, patients with a history of AR; Group 2, NODAT+; Group 3, NODAT+ AR+; and Group 4, the reference group (neither). Multivariate regression was used to analyze the relative risks for the outcomes of transplant failure and mortality. The median follow-up time was 1827 days after 1 year post-transplant. AR was associated with an increased risk of adjusted graft and death-censored graft failure (HR 2.87, CI 2.48-3.33, P < .001 and HR 2.11, CI 1.81-2.47, P < .001), respectively. NODAT and AR were identified in 3.5% and 14.5% of all study patients, respectively. AR in the first year post-transplant was a major risk factor for overall and death-censored graft failure, but not mortality. However, NODAT was not a risk factor on graft survival or mortality.

Surveillance biopsies after paediatric kidney transplantation: A review

Kidney transplantation is the most effective means of treating children with end-stage kidney disease, and yet, there continues to be a limited "life span" of transplanted kidneys in paediatric recipients. Early graft monitoring, using the surveillance biopsy, has the potential to extend renal allograft survival in paediatric recipients. The surveillance biopsy provides important and timely information about acute and chronic graft pathology, particularly SCR and calcineurin inhibitor-induced nephrotoxicity, which can subsequently guide management decisions and improve long-term graft survival. The ostensible value of the surveillance biopsy is furthered by the limitations of conventional renal functional studies. However, there is still much debate surrounding the surveillance biopsy in paediatric recipients, particularly in regard to its overall utility, safety and timing. This review discusses the current literature regarding the utility, safety, and potential predictive value of surveillance biopsies for guiding post-transplant management in paediatric renal allograft recipients, as well as the viability of other potentially newer non-invasive strategies for renal allograft monitoring.

High Risk of Graft Failure in Emerging Adult Heart Transplant Recipients

Emerging adulthood (17-24 years) is a period of high risk for graft failure in kidney transplant. Whether a similar association exists in heart transplant recipients is unknown. We sought to estimate the relative hazards of graft failure at different current ages, compared with patients between 20 and 24 years old. We evaluated 11 473 patients recorded in the Scientific Registry of Transplant Recipients who received a first transplant at <40 years old (1988-2013) and had at least 6 months of graft function. Time-dependent Cox models were used to estimate the association between current age (time-dependent) and failure risk, adjusted for time since transplant and other potential confounders. Failure was defined as death following graft failure or retransplant; observation was censored at death with graft function. There were 2567 failures. Crude age-specific graft failure rates were highest in 21-24 year olds (4.2 per 100 person-years). Compared to individuals with the same time since transplant, 21-24 year olds had significantly higher failure rates than all other age periods except 17-20 years (HR 0.92 [95%CI 0.77, 1.09]) and 25-29 years (0.86 [0.73, 1.03]). Among young first heart transplant recipients, graft failure risks are highest in the period from 17 to 29 years of age.

Identification of subgroups by risk of graft failure after paediatric renal transplantation: application of survival tree models on the ESPN/ERA-EDTA Registry

BACKGROUND

Identification of patient groups by risk of renal graft loss might be helpful for accurate patient counselling and clinical decision-making. Survival tree models are an alternative statistical approach to identify subgroups, offering cut-off points for covariates and an easy-to-interpret representation.

METHODS

Within the European Society of Pediatric Nephrology/European Renal Association-European Dialysis and Transplant Association (ESPN/ERA-EDTA) Registry data we identified paediatric patient groups with specific profiles for 5-year renal graft survival. Two analyses were performed, including (i) parameters known at time of transplantation and (ii) additional clinical measurements obtained early after transplantation. The identified subgroups were added as covariates in two survival models. The prognostic performance of the models was tested and compared with conventional Cox regression analyses.

RESULTS

The first analysis included 5275 paediatric renal transplants. The best 5-year graft survival (90.4%) was found among patients who received a renal graft as a pre-emptive transplantation or after short-term dialysis (<45 days), whereas graft survival was poorest (51.7%) in adolescents transplanted after long-term dialysis (>2.2 years). The Cox model including both pre-transplant factors and tree subgroups had a significantly better predictive performance than conventional Cox regression (P < 0.001). In the analysis including clinical factors, graft survival ranged from 97.3% [younger patients with estimated glomerular filtration rate (eGFR) >30 mL/min/1.73 m(2) and dialysis <20 months] to 34.7% (adolescents with eGFR <60 mL/min/1.73 m(2) and dialysis >20 months). Also in this case combining tree findings and clinical factors improved the predictive performance as compared with conventional Cox model models (P < 0.0001).

CONCLUSIONS

In conclusion, we demonstrated the tree model to be an accurate and attractive tool to predict graft failure for patients with specific characteristics. This may aid the evaluation of individual graft prognosis and thereby the design of measures to improve graft survival in the poor prognosis groups.

Loss of pediatric kidney grafts during the "high-risk age window": insights from pediatric liver and simultaneous liver-kidney recipients

Pediatric kidney transplant recipients experience a high-risk age window of increased graft loss during late adolescence and early adulthood that has been attributed primarily to sociobehavioral mechanisms such as nonadherence. An examination of how this age window affects recipients of other organs may inform the extent to which sociobehavioral mechanisms are to blame or whether kidney-specific biologic mechanisms may also exist. Graft loss risk across current recipient age was compared between pediatric kidney (n = 17,446), liver (n = 12,161) and simultaneous liver-kidney (n = 224) transplants using piecewise-constant hazard rate models. Kidney graft loss during late adolescence and early adulthood (ages 17-24 years) was significantly greater than during ages <17 (aHR = 1.79, 95%CI = 1.69-1.90, p < 0.001) and ages >24 (aHR = 1.11, 95%CI = 1.03-1.20, p = 0.005). In contrast, liver graft loss during ages 17-24 was no different than during ages <17 (aHR = 1.03, 95%CI = 0.92-1.16, p = 0.6) or ages >24 (aHR = 1.18, 95%CI = 0.98-1.42, p = 0.1). In simultaneous liver-kidney recipients, a trend towards increased kidney compared to liver graft loss was observed during ages 17-24 years. Late adolescence and early adulthood are less detrimental to pediatric liver grafts compared to kidney grafts, suggesting that sociobehavioral mechanisms alone may be insufficient to create the high-risk age window and that additional biologic mechanisms may also be required.

The impact of acute rejection in kidney transplantation on long-term allograft and patient outcome

BACKGROUND

Patients with end stage renal disease (ESRD) can be sustained with dialysis therapy.

OBJECTIVES

In this study, we followed up the effect of early acute and late acute rejections on survival rates of patients' grafts.

PATIENTS AND METHODS

We investigated the timing and frequency of acute rejection episodes related to long-term patient-graft survival in Taleghani hospital between 1990 and 2011. Recipients were divided into three groups as Group-1 (no rejection), Group-2 (early acute rejection [EAR]: less than 3-months) and Group-3 (late acute rejection [LAR]: after 3 months of transplant).

RESULTS

One and five-year patient's survival rates were 94.87% and 93.8%, and graft survival (GS) rates were 92.6% and 81.9%. EAR and LAR occurred in 125 (18.8%) and 77 (11.7%) patients, respectively. Graft and patient survival rates at one and five years were as follows; Group-1 (Graft 96.7% and 94.5% patient: 97.4% and 96.8%), Group-2 (Graft: 72% and 61%, patient: 85.6% and 84%), Group-3 (Graft: 84.4% and 36.8%, patient: 92.2% and 89.4%). Recipient age, type and length of dialysis, number of transplantations and the status of panel reactivity antibody (PRA) had no effect on the type of rejection. LAR was more commonly associated with males (P = 0.001) and donors' age was associated with rejection (P = 0.0002). Five-year GS rate among the three groups was lower in the LAR group (P < 0.0001).

CONCLUSIONS

LAR had a negative impact on long-term renal allograft survival and the risk of chronic graft dysfunction increased in patients with a history of LAR.

Racial and ethnic disparities in pediatric renal allograft survival in the United States

This study was undertaken to describe the association of patient race/ethnicity and renal allograft survival among the national cohort of pediatric renal allograft recipients. Additionally, we determined whether racial and ethnic differences in graft survival exist among individuals living in low or high poverty neighborhoods and those with private or public insurance. Among 6,216 incident, pediatric End Stage Renal Disease patients in the United States Renal Data System (kidney transplant from 2000 through September, 2011) 14.4% experienced graft failure, with a median follow-up time of 4.5 years. After controlling for multiple covariates, black race, but not Hispanic ethnicity, was significantly associated with a higher rate of graft failure for both deceased and living donor transplant recipients. Disparities were particularly stark by 5 years post-transplant, when black living donor transplant recipients experienced only 63.0% graft survival compared with 82.8% and 80.8% for Hispanics and whites, respectively. These disparities persisted among high and low poverty neighborhoods and among both privately- and publicly-insured patients. Notably profound declines in both deceased and living donor graft survival rates for black, compared to white and Hispanic, children preceded the 3-year mark when transplant Medicare eligibility ends. Further research is needed to identify the unique barriers to long-term graft success among black pediatric transplant recipients.

The impact of APOL1, CAV1, and ABCB1 gene variants on outcomes in kidney transplantation: donor and recipient effects

Dramatic improvements have been seen in short-term kidney allograft survival over recent decades with introduction of more potent immunosuppressant medications and regimens. Unfortunately, improvements in long-term graft survival have lagged behind. The genomics revolution is providing new insights regarding the potential impact of kidney donor genotypes on long-term graft survival. Variation in the donor apolipoprotein L1 (APOL1), caveolin 1 (CAV1), and multi-drug resistance 1 encoding P-glycoprotein genes (ABCB1) are all associated with graft survival after kidney transplantation. Although the precise mechanisms whereby these donor gene variants confer risk for graft loss have yet to be determined, these findings provide novel opportunities for modifying interactive environmental factors and optimizing kidney allocation with the ultimate goal of improving long-term graft survival rates.

A time-to-event model for acute rejections in paediatric renal transplant recipients treated with ciclosporin A

AIMS

Ciclosporin A (CsA) dosing in immunosuppression after paediatric kidney transplantation remains challenging, and appropriate target CsA exposures (AUCs) are controversial. This study aimed to develop a time-to-first-acute rejection (AR) model and to explore predictive factors for therapy outcome.

METHODS

Patient records at the Children's Hospital in Helsinki, Finland, were analysed. A parametric survival model in NONMEM was used to describe the time to first AR. The influences of AUC and other covariates were explored using stepwise covariate modelling, bootstrap-stepwise covariate modelling and cross-validated stepwise covariate modelling. The clinical relevance of the effects was assessed with the time at which 90% of the patients were AR free (t90).

RESULTS

Data from 87 patients (0.7-19.8 years old, 54 experiencing an AR) were analysed. The baseline hazard was described with a function changing in steps over time. No statistically significant covariate effects were identified, a finding substantiated by all methods used. Thus, within the observed AUC range (90% interval 1.13-8.40 h mg l⁻¹), a rise in AUC was not found to increase protection from AR. Dialysis time, sex and baseline weight were potential covariates, but the predicted clinical relevance of their effects was low. For the strongest covariate, dialysis time, median t90 was 5.8 days (90% confidence interval 5.1-6.8) for long dialysis times (90th percentile) and 7.4 days (6.4-11.7) for short dialysis times (10th percentile).

CONCLUSIONS

A survival model with discrete time-varying hazards described the data. Within the observed range, AUC was not identified as a covariate. This feedback on clinical practice may help to avoid unnecessarily high CsA dosing in children.

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.

Late acute rejection: incidence, risk factors, and effect on graft survival and function

Long-term graft survival and function has not kept pace with short-term success in kidney transplant (Tx) recipients. LAR ≥6 months post-Tx may contribute to lack of improvement; risk factors for LAR are not well known. Of 64 Tx recipients followed over six yr, 23 (35.9%) had LAR (LAR group) and 41 had no LAR (no LAR group). Of all variables, significant risk factors for LAR included DGF, (43.4% LAR vs. 14.6% in no LAR group, p = 0.0096); de novo DSA (65.2% vs. 26.8%, p = 0.003); mean COV% of TAC (41.8% vs. 34.6%, p = 0.03); and non-adherence (34.8% vs. 7.3%, p = 0.0043). DGF and DSA remained statistically significant (p = 0.002 and 0.003, respectively); COV% TAC had borderline significance (p = 0.057), and non-adherence was not significant on multivariate regression analysis. Patients with LAR had inferior graft survival and function, whereas graft function was stable in the no LAR group over a mean follow-up of 31.2 months. Patients with de novo DSA and DGF should be considered at risk of LAR; an early diagnosis and treatment of LAR may improve graft survival and function.

Age at graft loss after pediatric kidney transplantation: exploring the high-risk age window

BACKGROUND AND OBJECTIVE

The risk of graft loss after pediatric kidney transplantation increases during late adolescence and early adulthood, but the extent to which this phenomenon affects all recipients is unknown. This study explored interactions between recipient factors and this high-risk age window, searching for a recipient phenotype that may be less susceptible during this detrimental age interval.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

With use of Scientific Registry of Transplant Recipients data from 1987 to 2010, risk of graft loss across recipient age was quantified using a multivariable piecewise-constant hazard rate model with time-varying coefficients for recipient risk factors.

RESULTS

Among 16,266 recipients, graft loss during ages ≥17 and <24 years was greater than that for both 3-17 years (adjusted hazard ratio [aHR], 1.61; P<0.001) and ≥24 years (aHR, 1.28; P<0.001). This finding was consistent across age at transplantation, sex, race, cause of renal disease, insurance type, pretransplant dialysis history, previous transplant, peak panel-reactive antibody (PRA), and type of induction immunosuppression. The high-risk window was seen in both living-donor and deceased-donor transplant recipients, at all levels of HLA mismatch, regardless of centers' pediatric transplant volume, and consistently over time. The relationship between graft loss risk and donor type, PRA, transplant history, insurance type, and cause of renal disease was diminished upon entry into the high-risk window.

CONCLUSIONS

No recipient subgroups are exempt from the dramatic increase in graft loss during late adolescence and early adulthood, a high-risk window that modifies the relationship between typical recipient risk factors and graft loss.

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.

[Outcomes of pediatric renal transplantation in France]

Significant progress has been observed in pediatric renal transplantation over the last 20 years, leading to an increase in graft and patient survival. Mortality is low and is mainly due to infections, neoplasias and complications related to the initial disease. Graft survival is 67% at 10 years. Factors which influence graft survival are: donor type (results are better with a live donor), donor age, recipient age (with 2 periods at risk:<2 years old and teenagers), HLA incompatibilities, and recurrence of the initial disease. Chronic allograft nephropathy (CAN) is the major cause of late graft loss. Poor compliance, especially in teenagers, may lead to late rejections and graft loss. Calcineurin inhibitors nephrotoxicity is in part responsible for the development of CAN, thus treatments and the role of mTOR inhibitors will probably evolve. These different factors are discussed in this article.

The impact of age at transfer from pediatric to adult-oriented care on renal allograft survival

Immaturity among individuals transferred from pediatric to adult-oriented care at a young age may leave them vulnerable to higher graft failure risks than in individuals transferred older. We sought to determine the impact of age at transfer on renal allograft failure rates. We evaluated graft failure rates among 440 kidney recipients recorded in the UNOS database (1987-2007), who had been transferred from pediatric to adult care. Transfers were identified using the center codes recorded at yearly data collection. Failure rates for those transferred early (<21 yr old) were compared with rates for those transferred late (≥21 yr old); time-dependent Cox models were used to estimate the additional risk of graft failure associated with early vs. late transfer. The age-standardized failure rate was 12.9 per 100 person-years among those transferred early, and 8.7 per 100 person-years among those transferred late. Compared with individuals the same age who had transferred late, graft failure rates were 58% higher ([95% confidence interval: 7%, 134%], p = 0.02) among those who had transferred early. Younger age at transfer to adult care is associated with higher graft failure rates. Transfer to adult-oriented care at <21 yr of age should be undertaken with caution.

Estimation of renal allograft half-life: fact or fiction?

INTRODUCTION

Renal allograft half-life time (t½) is the most straightforward representation of long-term graft survival. Since some statistical models overestimate this parameter, we compare different approaches to evaluate t½.

PATIENTS AND METHODS

Patients with a 1-year functioning graft transplanted in Spain during 1990, 1994, 1998 and 2002 were included. Exponential, Weibull, gamma, lognormal and log-logistic models censoring the last year of follow-up were evaluated. The goodness of fit of these models was evaluated according to the Cox-Snell residuals and the Akaike's information criterion (AIC) was employed to compare these models.

RESULTS

We included 4842 patients. Real t½ in 1990 was 14.2 years. Median t½ (95% confidence interval) in 1990 and 2002 was 15.8 (14.2-17.5) versus 52.6 (35.6-69.5) according to the exponential model (P < 0.001). No differences between 1990 and 2002 were observed when t½ was estimated with the other models. In 1990 and 2002, t½ was 14.0 (13.1-15.0) versus 18.0 (13.7-22.4) according to Weibull, 15.5 (13.9-17.1) versus 19.1 (15.6-22.6) according to gamma, 14.4 (13.3-15.6) versus 18.3 (14.2-22.3) according to the log-logistic and 15.2 (13.8-16.6) versus 18.8 (15.3-22.3) according to the lognormal models. The AIC confirmed that the exponential model had the lowest goodness of fit, while the other models yielded a similar result.

CONCLUSIONS

The exponential model overestimates t½, especially in cohorts of patients with a short follow-up, while any of the other studied models allow a better estimation even in cohorts with short follow-up.

Access to Deceased Donor Kidney Transplants for Pediatric Patients in Latin America and the Caribbean

Las condiciones en que se da la asignación de órganos de paciente fallecido para trasplante es motivo de controversia. Objetivo. Conocer los criterios para la asignación de riñones de donante fallecido en el servicio de Pediatría de doce países de América Latina y el Caribe. Resultados. En diez países encuestados las listas de espera en Pediatría para un trasplante renal son regionales, generalmente por razones administrativas más que por disminuir los tiempos de isquemia fría, se realiza el HLA y se toma en cuenta en un sistema de puntaje para la elección del receptor final. En algunos países los riñones de donadores jóvenes (menores de 30 años) no siempre son para receptores pediátricos. Conclusión. La mayoría de los países de Latinoamérica y el Caribe cuentan con sistemas de puntaje para la asignación de órganos de donante fallecido y se privilegia a los niños. Guatemala y Nicaragua no cuentan con programa de donador fallecido, y en el caso de México, si bien tiene una estructura de trasplante en expansión, no se cuenta con un sistema de puntaje, y sólo algunos grupos de trasplante por iniciativa propia privilegian a los pacientes pediátricos. Es deseable que se haga un consenso al respecto en la comunidad de trasplantes latinoamericana para hacer una distribución menos subjetiva y más justa de los riñones de origen no vivo.

Recommendations for the assessment and reporting of multivariable logistic regression in transplantation literature

Multivariable logistic regression is an important method to evaluate risk factors and prognosis in solid organ transplant literature. We aimed to assess the quality of this method in six major transplantation journals. Eleven analytical criteria and four documentation criteria were analyzed for each selected article that used logistic regression. A total of 106 studies (6%) out of 1,701 original articles used logistic regression analyses from January 1, 2005 to January 1, 2006. The analytical criteria and their respective reporting percentage among the six journals were: Linearity (25%); Beta coefficient (48%); Interaction tests (19%); Main estimates (98%); Ovefitting prevention (84%); Goodness-of-fit (3.8%); Multicolinearity (4.7%); Internal validation (3.8%); External validation (8.5%). The documentation criteria were reported as follows: Selection of independent variables (73%); Coding of variables (9%); Fitting procedures (49%); Statistical program (65%). No significant differences were found among different journals or between general versus subspecialty journals with respect to reporting quality. We found that the report of logistic regression is unsatisfactory in transplantation journals. Because our findings may have major consequences for the care of transplant patients and for the design of transplant clinical trials, we recommend a practical solution for the use and reporting of logistic regression in transplantation journals.

Renal graft outcome after combined liver and kidney transplantation in children: UCLA and UNOS experience

Although it has been described in adults that renal grafts in the context of CLKT have a lower number of AR episodes and improved renal allograft survival, this has never been examined in pediatrics. We performed a single center retrospective case-control study examining 10 patients aged 10+/-6 yr with a CLKT that survived the post-surgery period of six months, and compared outcomes to a group of 20 KO transplants matched for age, era, and immunosuppression. We observed a significant reduction in the incidence of AR episodes in the CLKT group. To evaluate whether or not this experience was reproducible nationally, we performed an analysis of the 1995-2005 UNOS database. As of March 2007, 111 CLKT and 3798 KO transplants were identified from the OPTN/UNOS data. There was a significant improvement in the late kidney graft survival at five yr post-transplant in the CLKT group. These findings support the concept that liver transplantation is immunologically protective of the kidney allograft in CLKT.

Nucleic acid testing (NAT) of organ donors: is the 'best' test the right test? A consensus conference report

Nucleic acid testing (NAT) for HIV, HBV and HCV shortens the time between infection and detection by available testing. A group of experts was selected to develop recommendations for the use of NAT in the HIV/HBV/HCV screening of potential organ donors. The rapid turnaround times needed for donor testing and the risk of death while awaiting transplantation make organ donor screening different from screening blood-or tissue donors. In donors with no identified risk factors, there is insufficient evidence to recommend routine NAT, as the benefits of NAT may not outweigh the disadvantages of NAT especially when false-positive results can lead to loss of donor organs. For donors with identified behavioral risk factors, NAT should be considered to reduce the risk of transmission and increase organ utilization. Informed consent balancing the risks of donor-derived infection against the risk of remaining on the waiting list should be obtained at the time of candidate listing and again at the time of organ offer. In conclusion, there is insufficient evidence to recommend universal prospective screening of organ donors for HIV, HCV and HBV using current NAT platforms. Further study of viral screening modalities may reduce disease transmission risk without excessive donor loss.

Variables affecting estimated glomerular filtration rate after renal transplantation in children: a NAPRTCS data analysis

Short-term graft survival has improved in renal transplants without significant effect on long-term graft survival. As GFR decline precedes graft loss, an understanding of variables affecting eGFR after TX may help improve graft survival. NAPRTCS data were analyzed to assess effects of donor, recipient, and other variables on Schwartz eGFR after transplantation. For 8438 children with a functioning graft at day 30, data were censored for children dying with a functioning graft, and those with <3 yr follow-up. Multivariate linear regression and repeated measures analyses identified factors related to eGFR at day 30 after TX and during follow-up. Young, female, non-black, children without ATN and acute rejection in the first 30 days, TX after 1995, those with better eGFR at day 30, and receiving tacrolimus had better long-term eGFR. Transplant from ideal (6-35 yr) donors had best short-term eGFR, young donors (<5 yr) had lower eGFR and poor graft survival. After one yr, eGFR improved in surviving grafts of young donors and matched ideal donors. Acute rejection, BP medications, and hospitalizations in prior six months had negative association with subsequent eGFR. Regardless of variables, eGFR deteriorated with time. Slope of eGFR decline has not changed in the recent era indicating the need for innovative therapies.

Long-term outcome of intensive initial immunosuppression protocol in pediatric deceased donor renal transplantation

To report the long-term outcome of deceased donor kidney transplantation in children with emphasis on the use of an intensive initial immunosuppression protocol using R-ATG as antibody induction. Between January 1991 and December 1997, 82 deceased donor kidney transplantations were performed in 75 pediatric recipients. Mean recipient age at transplantation was 12.9 yr and the mean follow-up period was 12.6 yr. All patients received quadruple immunosuppression with steroid, cyclosporine, azathioprine, and antibody induction using R-ATG-Fresenius. Actual one, five, and 10 yr patient survival rates were 99%, 97%, and 94%, respectively; only one patient (1.2%) developed PTLD. Actual one, five, and 10 yr overall graft survival rates were 84%, 71%, and 50%, respectively; there were five cases (6%) of graft thrombosis and the actual immunological graft survival rates were 91%, 78%, and 63% at one, five, and 10 yr, respectively. The use of an intensive initial immunosuppression protocol with R-ATG as antibody induction is safe and effective in pediatric recipients of deceased donor kidneys with excellent immunological graft survival without an increase in PTLD or other neoplasms over a minimum 10-yr follow up.

Cyclosporine Versus Tacrolimus in Immunosuppressive Maintenance Regimens in Renal Transplants in Brazil: Survival Analysis from 2000 to 2004

BACKGROUND

In Brazil, the National Health System (SUS) is responsible for almost all renal transplants. SUS protocols recommend using cyclosporine, in association with azathioprine and corticosteroids, to maintain the immunosuppression that is essential for successful renal transplant. Alternatively, cyclosporine can be replaced by tacrolimus.

OBJECTIVE

To evaluate the effectiveness of therapeutic schema involving cyclosporine or tacrolimus after renal transplant during a 60-month follow-up period.

METHODS

A historical cohort study, from 2000 to 2004, was conducted using 5686 patients who underwent renal transplant and received cyclosporine or tacrolimus. Uni - and multivariate analyses were performed using the Cox model to examine factors associated with progression to treatment failure.

RESULTS

Most of the patients were male, aged 38 years or older, for whom the most frequent primary diagnosis of chronic renal failure (CRF) was glomerulonephritis/nephritis. Higher risk of treatment failure was associated with: therapeutic regimen (tacrolimus, HR 1.38, 95% CI 1.14 to 1.67), patient age at transplantation (additional year, HR 1.01, 95% CI 1.00 to 1.02), donor type (deceased, HR 1.60, 95% CI 1.35 to 1.89), median time of dialysis prior to transplantation (>24 mo, HR 1.29, 95% CI 1.09 to 1.52), and primary CRF diagnosis (diabetes, HR 1.54, 95% CI 1.09 to 2.17).

CONCLUSIONS

The risk of treatment failure of patients receiving tacrolimus was observed to be 1.38 times that of those receiving cyclosporine, after adjusting the model for possible confounding factors such as patient sex, patient age, graft origin, prior time of dialysis, and cause of CRF. Our results were obtained from an observational study, and further studies are necessary to evaluate whether compliance with SUS clinical protocols could result in more effective care for renal transplant recipients.

Ciclosporina versus tacrolimus no transplante renal no Brasil: uma comparação de custos

No Brasil, o Sistema Único de Saúde (SUS) é responsável maioria dos transplantes renais. Para a manutenção dessas intervenções, os protocolos recomendam uso da ciclosporina ou tacrolimus, associado com corticosteróides e azatioprina ou micofenolato. Na perspectiva do SUS, realizou-se análise econômica sobre recursos ambulatoriais, hospitalares e medicamentos utilizados por paciente e grupo terapêutico. Foi construída coorte de 2000 a 2004, com 5.174 pacientes em transplantes renais e em uso de ciclosporina ou tacrolimus, identificados por relacionamento probabilístico em registros do SUS. A coorte continha 4.015 pacientes em uso de ciclosporina e 1.159 com tacrolimus. A maioria era do sexo masculino, idade < 38 anos, cujos diagnósticos primários mais freqüentes eram nefrites, doenças cardiovasculares e causas indeterminadas. Após 48 meses, observou-se gasto superior para transplantes renais em hospitais do Nordeste, doador cadáver, naqueles em diálises > 24 meses antes do transplantes renais e no grupo do tacrolimus. Constatou-se maior gasto total com recursos hospitalares, ambulatoriais e medicamentos para os transplantes renais em pacientes com esquemas com tacrolimus, quando comparados com o grupo da ciclosporina.

The relationship of donor source and age on short- and long-term allograft survival in pediatric renal transplantation

Limited pediatric data on allograft survival from advanced aged kidney donors exist. To determine the influence of donor source and age on allograft survival in pediatric renal transplant recipients, we analyzed the OPTN database. Allograft survival for 7291 pediatric renal transplants was evaluated. Up to five yr post-transplantation, graft survival was higher for LD vs. DD recipients. At seven yr, allograft survival was 71% in 18-54 yr-old LD recipients, 59.1% in >or=55 yr-old LD, and 45.1% in >or=50 yr-old DD recipients. An approximate 35% improvement in allograft survival in 18-54 yr-old LD recipients was observed. Multivariate results showed that recipients of LD 35-49 (aRR 0.66, 95% CI 0.55-0.80) and LD 50-54 (aRR 0.65, 95% CI 0.45-0.94) have a graft survival advantage over the ideal DD. In LD >or=55 yr, no improvement in graft survival was observed when compared with the 18-34 yr-old DD. In summary, we observed in a pediatric population, <55 yr-old LD kidneys afford improved long-term allograft survival when compared with DD kidney recipients. Increasing awareness of the long-term graft survival advantage for children receiving an LD kidney, even from older donors, should be a priority.

Quantitative patterns of azathioprine adherence after renal transplantation

BACKGROUND

Renal transplant recipients regularly fail to take their prescribed immunosuppressive medications, frequently leading to adverse outcomes.

METHODS

Medication vials incorporating electronic monitor circuits in their caps compiled prospective data files on the azathioprine dosing patterns of 180 adult renal transplant recipients monitored up to 4 years. These patients were followed for a mean of 8.7 years posttransplantation.

RESULTS

Patients were divided into three groups by the medication doses missed during the first 6 months posttransplant. These initial dosing patterns remained remarkably consistent up to 4 years. Patients (n=47) missing the most doses (>or=5%) experienced earlier and more frequent acute rejection episodes (P=0.025). This group also demonstrated significantly longer interdose intervals (P=0.005), with more frequent (P<0.001) and longer (P<0.001) "drug holidays." A patient subgroup with early declining medication adherence (n=23) experienced dramatically poorer outcomes, with significantly increased acute rejection (P<0.001), chronic rejection (P=0.034), graft loss before death (P<0.001), and death (P=0.04). In all tertiles there was a trend toward missing more medication over time.

CONCLUSIONS

Excellent posttransplant medication adherence is critical to improved outcomes. Individual dosing patterns are established early after hospital discharge and remain remarkably consistent, despite gradual erosion in adherence over time. The later consequences of medication nonadherence, especially early declines in adherence, include increased frequencies of rejection, graft loss, and death.

Kidney transplantation and donation in children

It has been shown that kidney transplantation results in superior life expectancy and quality of life compared with dialysis treatment for patients with end-stage renal disease. However, kidney transplantation in children differs in many aspects from adult kidney transplantation. This review focuses on specific issues of surgical care associated with kidney transplantation in children, including timing of transplantation, technical considerations, patient and graft survival, growth retardation and post-transplant malignancy. At the same time, there is a large discrepancy between the number of available donor kidneys and the number of patients on the waiting list for kidney transplantation. There is a general reluctance to use paediatric donor kidneys, because of relatively frequent complications such as graft thrombosis and early graft failure. We review the specific aspects of kidney transplantation from paediatric donors such as the incidence of graft thrombosis, hyperfiltration injury and 'en bloc' transplantation of two kidneys from one donor with an excellent long-term outcome, which is comparable with adult donor kidney transplantation. We also discuss the potential use of paediatric non-heart-beating donor kidneys, from donors whose heart stopped beating with the preservation techniques used.

Long-term outcome after renal transplantation in childhood

The purpose of this article is to review: 1. Factors influencing long-term outcome data after transplantation 2. Patient survival overall, the effect of recipient age and donor type, causes of death, comparison of mortality after transplantation with that on dialysis, and effect of pre-emptive transplantation and race 3. Transplant survival overall, and the effect of recipient and donor age, donor type, pre-emptive transplantation, recurrent diseases, human leukocyte antigen (HLA) matching, immunosuppression, concordance, hypertension, bladder dynamics and type of donor nephrectomy 4. Final height and obesity 5. Psycho-social outcome.

Racial disparity trends for graft failure in the US pediatric kidney transplant population, 1980-2004

Graft survival among adult African American kidney transplant patients remains low compared to whites, but little information is available for children and adolescents. We examined trends in graft failure among US incident primary kidney transplant patients aged <19 years (n = 13 692), 1980-2004. Trends in 1-year and 2- to 5-year graft failure (for patients whose grafts survived the first year) were analyzed in 5-year intervals. One-year graft failure declined 70% for white and 77% for African American patients over the 25-year period, and 1-year graft failure rates improved at a slightly higher rate for African American compared to white patients (p = 0.02). In contrast, the graft failure rates for years 2-5 declined 53% for white and only 41% for African American patients over the 25 years (p = 0.29). In fully adjusted Cox proportional hazards analysis, the rate of graft failure among African Americans was approximately 2-fold higher than for white patients over the entire study period. Graft survival has improved slightly more for African American than white pediatric patients over the past 25 years. However, graft survival for African American pediatric patients remains poor compared with white patients.

Factors related to long-term renal transplant function in children

Short-term renal allograft survival in children has improved. It is therefore important to determine the factors leading to long-term graft function. To this end, we evaluated patients in the NAPTRCS registry who were <12 years old when they received their renal transplant between 1987 and 1993. Children with 10 years of post-transplant follow-up were compared to those in whom the transplant failed within 10 years. Children with a failed transplant within 10 years of the surgery tended to be older, female, and non-Caucasian; they also manifested obstructive uropathy less often and had focal segmental glomerulosclerosis more often, and they received more deceased donor kidneys. Children with a failed renal transplant had fewer HLA donor and recipient matches, received pre-transplant dialysis compared to a preemptive transplant, required dialysis in the first week post-transplant, and required more antihypertensives the first month post-transplant. Allograft function was examined at 10 years. Patients with continued allograft function and a serum creatinine <or=2 mg/dl at 10 years tended to be female and younger, received a younger donor kidney, and received a primary transplant. Serum creatinine, estimated glomerular filtration rate, weight Z score at 10 years, azathioprine use at 10 years, and antihypertensive use at transplant significantly predicted allograft function beyond 10 years. Pediatric transplant physicians should optimize the factors associated with improved long-term allograft function.

Balancing organ quality, HLA-matching, and waiting times: impact of a pediatric priority allocation policy for deceased donor kidneys in Quebec

Deceased donor kidney allocation policy must balance the desire for high-quality organs, good human leukocyte antigen (HLA) matching, and minimal waiting times. We describe a 10-fold reduction in waiting times and an improvement in nonimmunologic indices of organ quality for child recipients after a change in organ allocation policy in Quebec, Canada. The new policy gives first priority to children (<18 yr) irrespective of HLA matching or waiting time. HLA matching after the policy change was predictably much worse. This study highlights the trade-offs that must be considered both in setting allocation policy and in decisions for individual recipients. We also consider potential unintended negative effects of such a policy change.

Renal Transplantation in High-Risk Patients

Renal transplantation in high-risk patients is a growing phenomenon. More patients are progressing to endstage renal failure, in the setting of an increased incidence of diabetes mellitus and cardiovascular disease. Current organ shortages and the use of more marginal donors have affected both patient and graft survival. Acute rejection has been minimised under modern immunosuppression; however, patient and long-term allograft outcomes have not improved concurrently. Specific understanding of donor, recipient and allograft variables associated with stratification of patients as 'high risk for renal transplantation' is necessary to facilitate appropriate peri- and post-transplant pharmacotherapy. Induction and maintenance immunosuppression choices are different for high-risk patients and must be made to ensure optimal immunosuppression, while limiting patient and allograft toxicity.

Long-term outcome of paediatric renal transplantation: follow-up of 300 children from 1973 to 2000

BACKGROUND/AIM

To report our experience of paediatric renal transplantation at Great Ormond Street and Royal Free Hospitals since the inception of the programme.

METHODS

Retrospective review of the patient and transplant survival and influencing factors in the 300 children transplanted between 1973 and 2000.

RESULTS

300 children had received a total of 354 transplants; 56 were living-related donations. The median age at transplantation was 10.3 (range 1.4-17.9) years. Forty-four percent had congenital structural abnormalities of the urinary tract. Forty-six children required a second and 8 a third transplant before transfer to an adult unit. The overall patient survival at 5, 10, and 20 years was 97, 94, and 72%, respectively. In the overall cohort, the donor type (deceased donor or living-related donor) did not affect mortality, nor did age at transplantation, but those transplanted before 5 years of age had a significantly shorter post-transplant survival time (p < 0.0001). Transplant survival (first transplant) for deceased and living-related donors was 66 and 87% at 5 years (p < 0.01), 51 and 54% at 10 years, and 36% at 20 years (deceased-donor transplants only). Although the overall transplant survival was inferior in children transplanted before 2 years of age (p < 0.03), in the most recent cohort (1990-2000), age did not affect the outcome. On multiple regression analysis, the only predictor of transplant survival was the era of transplantation (p < 0.001). The median final height was within the normal range for males and females; 7 patients received growth hormone after transplantation.

CONCLUSIONS

The outlook for successful transplantation is improving, and in the last decade was unaffected by age at transplantation. The survival of living-related donor transplants is superior to deceased-donor transplants for the first 5 years. From the above data, we can predict that a 10-year-old child receiving a renal transplant in 2000 and on ciclosporin-based immunosuppression can expect a transplant half-life of 13.1 years from a living-related donor and one of 10.8 years from a deceased-donor transplant.