A decade of living donor transplantation in North American children: the 1998 annual report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS)

Combination of High-Dose Intravenous Cyclosporine and Plasma Exchange Treatment Is Effective in Post-Transplant Recurrent Focal Segmental Glomerulosclerosis: Results of Case Series

BACKGROUND

Idiopathic focal segmental glomerulosclerosis (FSGS) commonly recurs in the early post-transplant period. The treatment protocols and results are conflictive in recurrent FSGS. We aimed to present the results of our treatment protocol and basic approach to the disease recurrences.

METHODS

This prospective, single-center study was conducted between the years 2015 and 2018. Twelve patients who fit completely the diagnosis of idiopathic FSGS by clinical, laboratory, and biopsy findings were included. A specific treatment protocol which consists of plasma exchange and high dose intravenous cyclosporine was delivered to the patients independently of induction protocols. Twenty-four months of outcomes of graft functions were evaluated.

RESULTS

Nine patients completed the treatment protocol and were documented for evaluation. All patients achieved a complete or partial remission in an average 24 months of follow-up period.

CONCLUSION

Idiopathic FSGS is more commonly recurrent than thought to be. The early detection of proteinuria is crucial because the administration of a plasma exchange-based treatment protocol can reverse proteinuria. We think our treatment protocol is a well-established, efficient, and safe choice for post-transplant recurrent FSGS in adults.

Factors affecting growth and final adult height after pediatric renal transplantation

BACKGROUND

Growth retardation is a common problem for children with chronic kidney disease. Although renal transplantation (RTx) resolves endocrine metabolic and uremic disturbances, growth continues to be suboptimal. This study aims to describe changes in height from diagnosis to final adult height (FAH) in Korean renal allograft recipients and determine factors associated with posttransplantation growth.

METHODS

We retrospectively reviewed 63 renal allograft recipients who underwent RTx at <15 years of age with regular follow-up for >3 years afterwards. Pre- and post-RTx growth was analyzed by height Z scores (Ht_Z) at RTx, 2 and 5 years follow-up, and at FAH.

RESULTS

Ht_Z decreased from diagnosis to dialysis by -0.8 (P = .009) and from dialysis to RTx by -0.46 (P < .001). The mean baseline Ht_Z at RTx was -1.62 ± 1.36. The change in Ht_Z at 2 and 5 years after transplantation was 0.68 ± 0.88 and 0.48 ± 0.86, respectively. Both variables were negatively correlated with baseline age at RTx. Mean FAH was -1.22 ± 1.11 and was positively correlated with baseline height at RTx. Height at start of dialysis and dialysis duration were significant determinants of baseline height at RTx (P < .001).

CONCLUSIONS

Although there is significant posttransplant catch-up growth among younger recipients and among those with greater baseline height deficit, catch-up growth is not sustained and greater FAH is attained in those who are taller at RTx. Achieving greater height before dialysis and decreasing dialysis duration leads to maximal height at RTx as well as greater FAH.

Renal replacement therapy in infants with chronic renal failure in the first year of life

BACKGROUND AND OBJECTIVES

Although results of renal replacement therapy (RRT) in small children have improved during recent years, data about RRT in neonates are scarce.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In a retrospective study, we analyzed the outcome of infants who had chronic kidney disease and started RRT within their first year of life. Between 1997 and 2008, all 29 infants who were younger than 1 yr, had end-stage renal failure, and underwent RRT (dialysis or transplantation) at Hannover Medical School were analyzed for up to 12 yr.

RESULTS

Twenty-seven of 29 infants with chronic kidney disease received peritoneal dialysis, starting at a mean age of 112 d; two children received preemptive renal transplantation (RTx). During follow-up, 21 of 29 children survived with RTx. The 5-yr patient and graft survival rate after RTx was 95.5%. Six of 29 children died, one with a functioning graft and five while on peritoneal dialysis. The main causes of death were severe cardiovascular and cerebral comorbidities. The mean GFR at last follow-up of patients who underwent RTx (mean time after RTx 5.1 yr) was 63.2 ml/min per 1.73 m(2).

CONCLUSIONS

RRT in infants who are younger than 1 year offers excellent chances of survival and should be offered to all infants who do not have severe, life-limiting extrarenal comorbidity. Contrary to previous observations, the long-term outcome of infants may be comparable to that of older children who undergo RRT.

KDIGO clinical practice guideline for the care of kidney transplant recipients

The 2009 Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline on the monitoring, management, and treatment of kidney transplant recipients is intended to assist the practitioner caring for adults and children after kidney transplantation. The guideline development process followed an evidence-based approach, and management recommendations are based on systematic reviews of relevant treatment trials. Critical appraisal of the quality of the evidence and the strength of recommendations followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. The guideline makes recommendations for immunosuppression, graft monitoring, as well as prevention and treatment of infection, cardiovascular disease, malignancy, and other complications that are common in kidney transplant recipients, including hematological and bone disorders. Limitations of the evidence, especially on the lack of definitive clinical outcome trials, are discussed and suggestions are provided for future research.

Outcome after renal transplantation in children from native and immigrant families in Austria

Renal transplantation is the therapy of choice for children with end-stage renal disease (ESRD). Ethnicity affects the transplant survival rates substantially, but there has been no European academic evaluation of the effects of immigration on the pediatric renal transplantation outcome. The aim of this study was to compare the outcomes of renal transplantation between the children of immigrant families and the children of native families at the pediatric nephrology unit of the Medical University of Vienna, Austria. We conducted a retrospective study on all children who underwent renal transplantation at our center between January 1997 and June 2005. The patients were separated into two groups according to their immigration backgrounds. During the time frame of our study, 59 children underwent a total of 63 transplantations. Of these children, 42 were from native Austrian and 17 were from first-generation immigrant families. We analyzed the demographic data and outcome parameters for each of the 59 patients. We found no difference in patient and graft survival rates or long-term function between native and immigrant children. The two groups were also comparable in the rates of acute rejection episodes, 24-h blood pressure, and growth velocity. Living donor source had a positive influence on graft function (p=0.06), 24-h blood pressure (p=0.05), and growth velocity (p=0.02) only in the immigrant group. Our retrospective analysis shows no influence of the migration status on the patient or graft outcome, but we did find that immigrant children benefitted more than native children from living donation as opposed to deceased donation. To explain this fact, biological, heath-economical, psychosocial, and cultural background aspects must be investigated.

Contributions of the Transplant Registry: The 2006 Annual Report of the North American Pediatric Renal Trials and Collaborative Studies (NAPRTCS)

This summary of the NAPRTCS 2006 Annual Report of the Transplant Registry highlights the significant impact the registry has had in advancing knowledge in pediatric renal transplantation worldwide. This cooperative group has collected clinical information on children undergoing a renal transplantation since 1987 and now includes over 150 participating medical centers in the USA, Canada, Mexico, and Costa Rica. Currently, the NAPRTCS transplant registry includes information on 9837 renal transplants in 8990 patients (NAPRTCS 2006 Annual Report). Since the first data analysis in 1989, NAPRTCS reports have documented marked improvements in outcome after renal transplantation in addition to identifying factors associated with both favorable and poor outcomes. The registry has served to document and influence practice patterns, clinical outcomes, and changing trends in renal transplantation.

Pediatric live-donor kidney transplantation in Mansoura Urology & Nephrology Center: a 28-year perspective

Our objective was to evaluate our overall experience in pediatric renal transplantation. Between March 1976 and March 2004, 1,600 live-donor kidney transplantations were carried out in our center; 216 of the patients were 18 years old or younger (mean age 12.9 years). There were 136 male patients and 80 female patients. The commonest causes of end-stage renal disease (ESRD) were renal dysplasia (22%), nephrotic syndrome (20%), hereditary nephritis (16%), and obstructive uropathy (16%). Of the donors, 94% were one-haplotype matched and the rest were identical. Pre-emptive transplantation was performed in 51 (23%) patients. Triple-therapy immunosuppression (prednisone + cyclosporine + azathioprine) was used in 78.2% of transplants. Rejection-free recipients constituted 47.7%. Hypertension (62%) was the commonest complication. A substantial proportion of patients (48%) were short, with height standard deviation score (SDS) less than -1.88. The overall infection rate was high, and the majority (53%) of infections were bacterial. The graft survival at 1 year, 5 years and 10 years were 93.4%, 73.3% and 48.2%, respectively, while the patients' survival at 1, 5 and 10 years were 97.6%, 87.8% and 75.3%, respectively. Despite long-term success results of pediatric renal transplantation in a developing country, there is a risk of significant morbidity.

Immunosuppression in pediatric solid organ transplantation

This report reviews the immunosuppressive regimens that are used in pediatric transplantation. There are predominant themes developing in the field involving the minimization of the total exposure of immunosuppression through limiting the number of agents and newer pharmacokinetic modeling. Calcineurin inhibitors are the foundation of most immunosuppressive regimens. However, there are new pharmacologic monitoring techniques to reduce the potential for long-term side effects of this class of agents. Although tacrolimus remains one of the mainstays of current protocols, there are strides being made to reduce the patient's long-term exposure to it with transitioning to sirolimus. Corticosteroids are still used predominantly, but there is growing evidence of successful steroid-sparing protocols that are as effective and avoid the chronic morbidity of steroids. Antibody induction therapy remains a standard with clearer evidence of the efficacy of IL-2 receptor antagonists. There is preliminary clinical evidence that polyclonal antibody therapy is efficacious in pediatric transplantation. Future studies will determine the best way to assess the functional immune status of a pediatric transplant recipient to maintain the fine balance and avoid the complications of either excessive or inadequate immunosuppression.

Stable graft function after reduction of calcineurin inhibitor dosage in paediatric kidney transplant patients

BACKGROUND

Chronic calcineurin inhibitor (CNI) toxicity contributes to the development and progression of chronic allograft nephropathy (CAN), which is still the major cause of transplant dysfunction and graft loss. Reduction in dosage of CNI may delay the development of CAN, leading to longer graft survival.

METHODS

Therefore, 19 paediatric kidney transplant patients under immunosuppressive therapy with CNI (12/19 ciclosporin A, CSA, 7/19 tacrolimus, Tac), mycophenolat mofetil and some patients on steroids were included in a prospective study. Over a period of 9 months CNI dosage was stepwise reduced from CSA trough levels of 100-150 ng/ml to 50-70 ng/ml and Tac trough levels of 5-8 ng/ml to 2-3 ng/ml, respectively.

RESULTS

Glomerular filtration rate was stabilized in patients after CSA and Tac reduction. One borderline rejection occurred in a patient prior to reduction of Tac. In patients on CSA, one interstitial cellular rejection (BANFF IA) was noted. Reduction of CNI had no significant effects on blood pressure, lipid status and the infection frequency.

CONCLUSIONS

In paediatric kidney transplant patients, reduction of CNI down to low trough levels stabilizes renal function. However, the risk of acute rejection episodes may be increased. Therefore, further studies based on protocol biopsies within a randomized trial are warranted.

Safety and efficacy of a calcineurin inhibitor avoidance regimen in pediatric renal transplantation

Thirty-four children were entered into a pilot trial of calcineurin inhibitor avoidance after living-donor kidney transplantation, the CN-01 study. Patients were treated with anti-CD25 mAb, prednisone, mycophenolate mofetil, and sirolimus. Twenty patients were maintained on the protocol for up to 3 yr of follow-up. One enrolled patient did not receive the transplant because of a donor problem, eight terminated because of one or more rejection episodes, four terminated because of adverse events, and one was lost to follow-up. Two grafts were lost, one as a result of chronic rejection and the other as a result of posttransplantation lymphoproliferative disorder. There were no deaths. The 6- and 12-mo acute rejection rates were 21.8 and 31.5%, respectively. GFR were stable throughout the course of the study, with a slight downward trend by 6 mo after transplantation followed by a slight upward trend to a mean of 70 ml/min thereafter. Early surveillance graft biopsies frequently showed focal interstitial mononuclear cellular infiltrates without overt vasculitis or tubulitis, but these infiltrates disappeared without treatment. Anti-HLA class I and II antibodies were detected in three patients before transplantation, and all three had acute rejections, including the two patients who lost their grafts. De novo anti-HLA Ab production occurred in only one patient after transplantation. There were two episodes of Epstein Barr virus-related posttransplantation lymphoproliferative disorder, one of which developed after the patient had been terminated from the study. It is concluded that calcineurin inhibitor-free immunosuppression can be safe and effective in pediatric living-donor renal transplantation. However, further modifications that are designed to lessen early rejection rates and decrease complications should be tested before this approach is used routinely.

Mycophenolate mofetil introduction stabilizes and subsequent cyclosporine A reduction slightly improves kidney function in pediatric renal transplant patients: a retrospective analysis

Chronic allograft nephropathy (CAN) is the major cause of late graft loss. Among others, chronic calcineurin inhibitor toxicity (CNI) contributes to the development of CAN. Therefore, reduction in CNI dosage may delay the development of CAN, leading to longer graft survival. It was the aim of the present retrospective analysis to investigate the effect of mycophenolate mofetil (MMF) addition with subsequent cyclosporine A (CSA) reduction on renal function in pediatric kidney allograft recipients. Seventeen patients (aged 8.3-17.6 yr) with monotherapy with CSA and progressive loss of renal function at a median of 3.4 yr after kidney transplantation were enrolled. After at least three months of MMF treatment, CSA dosage was stepwise reduced to trough levels of 100, 80, and 60 ng/mL. In all patients, introduction of MMF prevented a further decrease of glomerular filtration rate (GFR). The mean GFR 12 months before study enrollment was 96.1+/-24.5 and 71.0+/-21.0 mL/min/1.73 m2 at start of MMF. After introduction of MMF and unchanged CSA dosage GFR was stabilized to 71.1+/-23.8 mL/min/1.73 m2. After CSA reduction to trough levels of 60 ng/mL, GFR was slightly ameliorated up to 76.3+/-24.1 mL/min/1.73 m2. Within the follow-up period, one borderline rejection occurred in a patient in whom the CSA trough level was 60 ng/mL since seven months. In pediatric kidney allograft recipients with progressive loss of renal function reduction of CSA after introduction of MMF may stabilize and even slightly ameliorate renal function.

Pediatric renal transplantation: comparative study with renal transplantation in the adult population

PURPOSE

To retrospectively review our experience with pediatric renal transplantation and to compare the results with the adult population.

PATIENTS AND METHODS

Between January 1981 and August 2003, 74 renal transplants were performed in patients < or =18 years at the time of the transplant--the pediatric group versus 1153 patients in the adult group. We analyzed various risk factors for actuarial kidney graft and patient survivals using the Kaplan-Meier method.

RESULTS

Median ages were 13.8 +/- 3.5 and 42.6 +/- 2.4 years, respectively. There was no statistically significant difference in the human leukocyte antigen matching or immunosuppression. There was, however, a younger donor age and shorter ischemia time in the pediatric group. Overall, kidney transplant survival rates for patients < or =18 years at 1, 2, 5, and 10 years were 94.4%, 91.3%, 70.6%, and 58.2%, respectively, with no significant difference for patients older than 18 (91.2%, 89.3%, 78.8%, 60.5%, P = .4325). There was a significantly decreased graft survival in the adult group at 10 years when the donor age was over 60 years and when the ischemia time was > or =20 hours. The incidence of delayed graft function and the creatinine levels of functioning grafts did not differ between the two groups. During the follow-up, acute rejections were more frequent in the younger group. Patient survival in the pediatric group at 1, 2, 5, and 10 years was 98.6%, 98.8%, 98.6%, and 90.3%, respectively, significantly lower in the adult group (95.3%, 94.0%, 87.9%, 76.8%, P < .02).

CONCLUSIONS

Renal transplantation may be successfully performed in the pediatric patients with end-stage renal disease. Overall graft survival at 10 years did not differ significantly between the two groups. There is a higher incidence of acute rejections but longer patient survival in the pediatric population.

Laparoscopic donor nephrectomy gene expression profiling reveals upregulation of stress and ischemia associated genes compared to control kidneys

We compared gene expression profiles from six donor kidneys prior to surgical manipulation to six kidneys removed after laparoscopic donor nephrectomy (LDN) and several hours of CO2 pneumoperitoneum. Biopsies were obtained from renal cortex and hybridized to Affymetrix HG-U133A GeneChips. For control kidneys, we identified 1380 genes present on all six samples that had a signal intensity >1,000. Functional classification of these revealed genes for cellular signaling (201; 15%), regulation of transcription (156; 11%), cellular transport (144; 10%) and cellular metabolism (111; 8%). A class comparison between the controls and LDN kidneys yielded 865 differentially expressed genes. Functional classification of the 502 genes differentially upregulated in LDN kidneys identified associations with apoptosis, cell adhesion, cell signaling, regulation of cell growth/proliferation, immune/inflammation, ischemia/stress response and proteolysis/peptidolysis. These data demonstrate an altered renal transcriptome induced by several hours of CO2 pneumoperitoneum and laparoscopic surgery characterized by upregulation of ischemia and injury associated genes.

Determinants of graft survival in pediatric and adolescent live donor kidney transplant recipients: a single center experience

To study the independent determinants of graft survival among pediatric and adolescent live donor kidney transplant recipients. Between March 1976 and March 2004, 1600 live donor kidney transplants were carried out in our center. Of them 284 were 20 yr old or younger (mean age 13.1 yr, ranging from 5 to 20 yr). Evaluation of the possible variables that may affect graft survival were carried out using univariate and multivariate analyses. Studied factors included age, gender, relation between donor and recipient, original kidney disease, ABO blood group, pretransplant blood transfusion, human leukocyte antigen (HLA) matching, pretransplant dialysis, height standard deviation score (SDS), pretransplant hypertension, cold ischemia time, number of renal arteries, ureteral anastomosis, time to diuresis, time of transplantation, occurrence of acute tubular necrosis (ATN), primary and secondary immunosuppression, total dose of steroids in the first 3 months, development of acute rejection and post-transplant hypertension. Using univariate analysis, the significant predictors for graft survival were HLA matching, type of primary urinary recontinuity, time to diuresis, ATN, acute rejection and post-transplant hypertension. The multivariate analysis restricted the significance to acute rejection and post-transplant hypertension. The independent determinants of graft survival in live-donor pediatric and adolescent renal transplant recipients are acute rejection and post-transplant hypertension.

Risk for post-transplant lymphoproliferative disorder after polyclonal antibody induction in kidney transplantation

The adjusted relative risk (aRR) for development of post-transplant lymphoproliferative disorder (PTLD) is higher in kidney transplant recipients receiving monoclonal antibody induction therapy, but the aRR between the different available polyclonal agents has not been investigated in detail. We analyzed data from the United Network of Organ Sharing registry on all kidney transplants performed between 1987 and 2003. The aRR for PTLD development was calculated using SAS 9.0 statistical software and Cox proportional hazards modeling, adjusting for multiple covariates. There were 539 cases of PTLD among 84 907 kidney transplant recipients, who received either polyclonal antibody induction or no induction therapy. In adjusted analysis, the aRR for PTLD development (vs. no induction) was significantly higher with use of equine anti-thymocytic globulin (E-ATG; aRR = 1.61, p = 0.0003) or anti-lymphocytic globulin (ALG; aRR = 1.35, p = 0.0055) but not with rabbit anti-thymocytic globulin (R-ATG; aRR = 1.17, p = 0.29, NS). Median follow up times were significantly shorter in the R-ATG cohort than the ALG or E-ATG cohort (median 368 vs. 1433 and 2055 day). However, in an analysis restricted to pediatric recipients, where median times to PTLD are less than 200 days, only E-ATG was associated with a higher aRR for PTLD (aRR = 2.16, p = 0.0078), while R-ATG and ALG were not. There is a higher aRR for PTLD after kidney transplantation with E-ATG, but not R-ATG. This may only partially be explained by shorter follow up time and may represent differential hazard for PTLD among the agents.

A randomized multicenter trial of OKT3 mAbs induction compared with intravenous cyclosporine in pediatric renal transplantation

Acute rejection leading to renal graft failure is more frequent among children. In patients treated with T cell antibody induction, retrospective data from the pediatric registry show a 22% reduction in the risk of graft failure. We conducted a randomized trial (n = 287) using OKT3 mAbs in one (OKT3) arm and intravenous cyclosporine in the other arm (CYS). Maintenance therapy consisted of randomized, double blind Sandimmune or Neoral together with prednisone and either azathioprine (AZA) or mycophenolate mofetil (MMF). Morbidity, mortality, rejection rates and adverse reactions in the two study arms were similar. Through 4 yr, graft failure was 27% in OKT3 and 19% in CYS (p = 0.15). One-year graft survival was 89.1% in OKT3 and 89.2% in CYS (p = .19). In multivariate analysis, OKT3 had a numerically inferior graft survival (RR = 1.4, CI 0.8-2.2, p = 0.22). In OKT3 graft survival was inferior for children aged 6 yr or younger. Our trial demonstrates that the incidence of acute rejection or graft failure in pediatric patients is not improved by OKT3 induction therapy relative to cyclosporine induction.

Thymoglobulin Versus ATGAM Induction Therapy in Pediatric Kidney Transplant Recipients: A Single-Center Report

BACKGROUND

Induction immunosuppressive therapy with the anti-T-cell antibody Thymoglobulin decreases the incidence of acute rejection in adult kidney transplant (KTx) recipients, but limited data are available for pediatric KTx recipients.

METHODS

We conducted a historical cohort study to compare rates of survival, rejection, and infection in pediatric (age <19 years) KTx recipients who received induction therapy with polyclonal antibody, ATGAM (n=127) or Thymoglobulin (n=71), from December 1, 1992, to January 31, 2003. Maintenance immunosuppression included cyclosporine, azathioprine or mycophenolate mofetil, and prednisone. Mean follow-up was 90+/-25 months for ATGAM recipients and 32+/-15 months for Thymoglobulin recipients.

RESULTS

Overall, the incidence of acute rejection was lower in Thymoglobulin recipients versus ATGAM recipients (33% vs. 50%, P=0.02). Epstein-Barr virus (EBV) infection was higher in Thymoglobulin recipients versus ATGAM recipients (8% vs. 3%, P=0.002). But the two groups did not significantly differ in patient and graft survival rates, incidence of chronic rejection, EBV lymphoma, or other infection.

CONCLUSIONS

Thus, Thymoglobulin induction was associated with a decreased incidence of acute rejection and an increased incidence of EBV infection in pediatric KTx recipients. EBV monitoring should be performed in EBV-naive recipients receiving Thymoglobulin.

Open-Label, Multicenter Study on the Safety, Tolerability, and Efficacy of Simulect in Pediatric Renal Transplant Recipients Receiving Triple Therapy With Cyclosporin, Mycophenolate, and Corticosteroids

INTRODUCTION

Basiliximab is a monoclonal antibody directed to the interleukin-2 receptor. Several studies have demonstrated both its efficacy and safety. Even with the use of polyclonal antibodies in renal pediatric transplant recipients, the local incidence of steroid-resistant rejections has been close to 10% of the total incidence of acute rejection episodes (AREs). An open, multicenter prospective study was performed to assess the safety tolerability, and efficacy of induction with basiliximab in renal pediatric transplant patients receiving cyclosporine, mycophenolate, and steroids.

MATERIALS AND METHODS

Eighteen patients (8 boys) of mean age 11.9 +/- 4.5 years and body weight 32 +/- 15 kg received cadaveric (n = 7) or living (n = 11) donor grafts. Simulect was administered on days 0 and 4. Efficacy was assessed by the incidence of biopsy-proven acute rejection (BPAR). Safety assessment consisted of a description of the adverse events (AEs).

RESULTS

Six BPAR (Banff I and II) occurred in 5, (27.7%) children all of which were steroid responsive. Creatinine levels at day 7 and months 3, 6, and 12 were 1.6 +/- 1.5 mg/dL, 1.0 +/- 0.4 mg/dL, 1.0 +/- 0.5 mg/dL, and 1.0 +/- 0.4 mg/dL, respectively. Schwartz calculation at 12 months was 71 +/- 15 mL/1.73 m2 AEs were hypertension (12), anemia (9), abdominal pain (8), metabolic acidosis (8), nausea (7), diarrhea (2), gingival hypertrophy (2), hirsutism (2), lymphocele (2), and infections (15). No deaths, graft losses, PTLDs, or malignancies were observed.

CONCLUSIONS

No steroid-resistant AREs, were observed in this pediatric group using basiliximab. The Schwartz calculation at 12 months was 71 +/- 15 mL/min/1.73 m2.

Improved outcome of pediatric kidney transplantations in the Netherlands -- effect of the introduction of mycophenolate mofetil?

Collaboration of the Dutch centers for kidney transplantation in children started in 1997 with a shared immunosuppressive protocol, aimed at improving graft survival by diminishing the incidence of acute rejections. This study compares the results of transplantations in these patients to those in a historical reference group. Ninety-six consecutive patients receiving a first kidney transplant were treated with an immunosuppressive regimen consisting of mycophenolate mofetil, cyclosporine and corticosteroids. The results were compared with those of historic controls (first transplants between 1985 and 1995, n = 207), treated with different combinations of corticosteroids, cyclosporine A and/or azathioprine. Cytomegalovirus (CMV) prophylaxis was prescribed to high-risk patients in the study group, and only a small proportion of the reference group. The graft survival at 1 yr improved significantly: 92% in the study group, vs. 73% in the reference group (p < 0.001). In the study group 63% of patients remained rejection-free during the first year; in the reference group 28% (p < 0.001). After statistical adjustment of differences in baseline data, as cold ischemia time, the proportion of LRD, preemptive transplantation, and young donors, the difference between study and reference group in graft survival (RR 0.33, p = 0.003) and incidence of acute rejection (RR 0.37, p < 0.001), as the only factor, remained statistically significant, indicating the effect of the immunosuppressive therapy. In the first year one case of malignancy occurred in each group. CMV disease occurred less frequently in the study group (11%) than in the reference group (26%, p = 0.02). As a new complication in 4 patients bronchiectasis was diagnosed. A new consensus protocol, including the introduction of mycophenolate mofetil, considerably improved the outcome of pediatric kidney transplantation in the Netherlands, measured as reduction of the incidence of acute rejection and improved graft survival.

Laparoscopic live donor nephrectomy: a risk factor for delayed function and rejection in pediatric kidney recipients? A UNOS analysis

The impact of laparoscopic (vs. open) donor nephrectomy on early graft function and survival in pediatric kidney recipients (< or =18 years) is unknown. We studied 995 pediatric live donor txs reported to UNOS from January 2000 to June 2002, in two recipient age groups: 0-5 years (n = 212, 44% laparoscopic donors [LapD]) and 6-18 years (n = 783, 50% LapD). Delayed graft function (DGF) rates were higher for LapD versus open donor (OpD) txs (0-5 years, 12.8% vs. 2.5% [p = 0.004]; 6-18 years, 5.9% vs. 2.8% [p = 0.03]). Acute rejection incidence for LapD versus OpD txs was higher at 6 months for recipients 0-5 years (18.6% vs. 5.9%, p = 0.01) and 6-18 years (22.5% vs. 15.6%, p = 0.03), and 1 year for recipients 0-5 years (24.3% vs. 7.9%, p = 0.004). In multivariate analyses, significant independent risk factors for rejection at 6 months and 1 year were recipient age 6-18 years, pretx dialysis, LapD nephrectomy and DGF. Graft survival was similar for LapD versus OpD txs. In this retrospective UNOS database analysis, LapD procurement was associated with increased DGF and an independent risk factor for rejection during the first year, particularly for recipients 0-5-years old. Future investigations must confirm these findings and identify strategies to optimize procurement and pediatric recipient outcome.

Experience with cyclosporine in pediatric renal transplantation

Three decades ago renal transplantation had become the accepted therapy for end-stage renal disease in children. Cyclosporine (CsA) was introduced into the majority of clinical immunosuppressive protocols in the 1980s and attained a vital place in the armamentarium of antirejection drugs for children. However, CsA therapy is not without adverse effects, notably posttransplant hypertension, hyperlipidemia, and nephrotoxicity. The cosmetic side effects of CsA, principally hirsutism and gum hyperplasia, are significant and very important to children particularly when drug compliance issues are vital to achieve success. The central role CsA has played to date in the development of successful treatment protocols for children undergoing renal transplantation is explored, including the importance of therapeutic drug level monitoring to optimize clinical outcomes.

Medical and surgical aspects of pediatric renal transplantation using living donors

The outcomes of 19 consecutive living-donor renal transplants (LD-RTx) was compared with 41 cadaveric grafts (CD-RTx) performed at our institution using basiliximab, cyclosporine, and prednisone as standard immunosuppression. LD-RTx significantly shortened the waiting time on dialysis. However, patient survival (100% in both groups), 1-year graft survival (94.7% vs 90%), and rejection-free graft survival (76.9% vs 73.5%) was not significantly different. LD-RTx showed better glomerular filtration rates in the early phase after transplantation, a difference that faded with time. Graft function was similar after 1 and 2 years. LD grafts with double renal arteries were used successfully in four cases; heparin therapy was administered to avoid graft thrombosis. A significantly greater number of lymphoceles was observed with LD grafts (7/19 vs 1/41, P < .01). In conclusion with improved immunosuppression producing better results with CD grafts, the advantages of LD-RTx have vanished. LD grafts with double arteries may be used successfully and LD-RTx allows a shorter dialysis period. The high incidence of lymphoceles in our series awaits further evaluation.

Noncompliance with immunosuppressive medications in pediatric and adolescent patients receiving solid-organ transplants

Advances in knowledge in transplantation have improved 1-year renal allograft survival in all age groups of pediatric patients. However, the results from many studies have shown that the long-term allograft survival is least successful in adolescent recipients. The major cause of late graft failure in adolescents can be contributed in large measure to medication noncompliance. Medication noncompliance in teenagers has been shown to be more than four times greater in adolescents than in adults. The teenage years are a time of transition from childhood to adulthood. Important tasks during this transition include the development of an autonomous identity that progresses to full independence. However, the cognitive skills and intellectual maturation of adolescents are still limited, and this is particularly true in adolescents with chronic diseases. They have difficulty with abstract thinking, particularly the conceptualization of future consequences of present actions. This leads to characteristic risk-taking behaviors, including noncompliance with medical treatments. This transition is more intricate for adolescents with chronic illness because of their physical limitations. There are a number of strategies that are helpful in mitigating noncompliance. Adolescents must be dealt with directly. Previous noncompliant behaviors need to be acknowledged and dealt with, because studies show that noncompliance is a "stable" personality attribute that persists over time. Efforts should be made to choose medications that have the least side effects. Psychological and psychiatric conditions such as posttraumatic stress disorder require early recognition, diagnosis, and treatment. It is necessary to build rapport with teenagers, and this should start before transplantation. A multidisciplinary approach with physicians, social workers, nurses, and transplant coordinators is an effective mean of enhancing compliance. These and other strategies outlined in this discussion will enable the adolescent to achieve good compliance rates and prevent graft loss.

Nephrotic syndrome after conversion to alternate day steroids in two children with a history of recurrent FSGS

FSGS is a common indication for kidney transplantation in children. However, transplantation is often complicated by recurrence of FSGS in the transplanted kidney, resulting in nephrotic syndrome and an increased risk of graft loss. Acute treatment strategies for recurrent FSGS include plasmapheresis and increased immunosuppressive therapy. There is little information on the long-term management of immunosuppression in these patients. We describe two children who were successfully treated with plasmapheresis for recurrent FSGS that occurred immediately post-transplant. Nephrotic syndrome reappeared years later when the patients were converted from daily to alternate day prednisone. In children with a history of FSGS, caution is necessary when altering the dosing schedule of prednisone.

Changing trends in pediatric transplantation: 2001 Annual Report of the North American Pediatric Renal Transplant Cooperative Study

The North American Pediatric Renal Transplant Cooperative Study has collected clinical information on children undergoing a renal transplantation since 1987. This cooperative group now includes over 150 participating medical centers in the United States, Canada, Mexico, and Costa Rica. This report covers the years from 1987 through 2001 and includes data on 7545 renal transplants in 6878 patients. This report demonstrates changing trends in many areas of pediatric transplantation including increasing numbers of African American and Hispanic children receiving transplantation, remarkable improvements in the rate of acute rejection, rejection reversal, and short- and long-term allograft survival. In the most recent cohorts of patients, we now see that 1-yr allograft survival is no different in cadaver donor compared to living donor recipients and in infants compared to all other age groups. However, this analysis also reveals areas of continued challenges including inferior outcomes in African American and adolescent populations, chronic rejection, and the adverse effects of immunosuppression.

A longitudinal study of children who received renal transplants 10-20 years ago

BACKGROUND

We have previously reported on our 10-year experience of renal transplantation in children in the cyclosporine era, that is, from December 1981 until December 1991. In this paper, we report on the same children observed for another 10 years.

METHODS

Of 53 children who received a renal transplant between 1981 and 1991, 47 survived and were observed for 10 to 20 years. Immunosuppression consisted of cyclosporine, prednisolone, and azathioprine. Yearly clinical examinations were performed.

RESULTS

Overall, actual patient survival is 91%, 89%, and 89%, and actual graft survival 85%, 77%, and 66% at 1, 5, and 10 years, respectively. No patients have died during the last 10 years. Twenty-six grafts were lost over 20 years. Thirteen of those were lost during the present follow-up (10-20 years): 11 in chronic rejection and 2 because of development of renal cell carcinoma. No other malignancies were noted. Mean glomerular filtration rate decreased from 58+/-19 at 1 year (n=42) to 44+/-16 mL/min/1.73 m2 body surface area at 10 (n=33) years. Hypertension was treated in 46%, 40%, and 66% of the children at 1, 5, and 10 years, respectively; two of them showed left ventricular hypertrophy 10 years after transplant. Minor cataracts without visual disturbance were found in 45% of patients. All children except three with mental retardation are, or have been, attending normal day care or normal school.

CONCLUSION

Social integration is good, and severe complications are scarce, even when renal transplantation occurred at a very young age.

Hyperlipidemia in pediatric kidney transplant recipients treated with cyclosporine

Hyperlipidemia is a risk factor for cardiovascular disease in adult kidney transplant (Tx) recipients. We sought to determine the prevalence of, and the risk factors associated with, hyperlipidemia in pediatric kidney Tx recipients on cyclosporine (CsA). We identified 59 patients (mean age 8.2+/-5.7 years) transplanted between 1 January 1991 and 31 December 1993. Pre Tx, 34% had elevated total cholesterol [TC >200 mg/dl (5.17 mmol/l)]; 54% had elevated triglycerides [TG >200 mg/dl (2.26 mmol/L)]. Mean TG was higher pre Tx in dialysis (versus nondialysis) patients: 306 mg/dl (3.46 mmol/l) versus 228 mg/dl (2.58 mmol/l) ( P=0.04). Mean TC was higher in peritoneal dialysis than hemodialysis patients: 222 mg/dl (5.74 mmol/l) versus 169 mg/dl (4.37 mmol/l) ( P=0.03). Pre Tx and 3-year values correlated (TC, r=0.49, P=0.0008; TG, r=0.41, P=0.001); 3- and 5-year TC values correlated ( r=0.57, P=0.003). At 5 years post Tx, 41% of the recipients had elevated TC; 14% had elevated TG. Recipients with elevated TC had higher mean CsA concentrations at 1 year post Tx ( P=0.03). Recipients with elevated TG tended to receive more prednisone ( P=0.06). At 5 years post Tx, recipients had a high prevalence of hyperlipidemia. The identification and treatment of hyperlipidemia should be included in pediatric kidney Tx protocols.

Growth impairment at renal transplantation--a determinant of growth and final height

Long-term outcome of growth and final adult height (FH) are a major concern of children after a renal transplantation (Tx). We therefore studied the yearly measurements of height (Ht), expressed as the Z-score and bone age (BA), in 58 children (28 girls) transplanted in our departments and followed-up for 5-18 (mean 9.6) yr after the operation. Twenty-four children reached final adult height. Renal function was evaluated as the glomerular filtration rate (GFR), which is estimated from the clearance of inulin. The mean Ht Z-score at Tx was -1.3 in girls and -2.7 in boys and increased to -0.6 and -1.5, respectively, at 5 yr after Tx. The greatest increase, seen in the shortest children and those transplanted before 7 yr of age, occurred during the first 3 yr. Children aged 7-12 yr at Tx showed an increase in height during the first years after the transplant, while those transplanted at >12 yr of age were not growth-retarded and therefore did not change their Ht Z-score. The most growth-retarded were also the most BA retarded. The mean FH Z-score was -1.1. A direct correlation was seen between GFR at 1 yr after Tx and the increase in height Z-score from Tx to 1 and 5 yr after Tx. In summary, the increment in height following Tx was the greatest in the most growth-retarded children and most marked during the first 3 yr after the transplant. FH was within normal range in 75% of the children. A high Ht Z-score at Tx had a positive effect on FH. Thus, growth after Tx was affected by the degree of stunting at Tx and renal function after Tx.

Therapy for acute rejection in pediatric organ transplant recipients

Despite the availability of potent immunosuppressive drugs, rejection after organ transplantation in children remains a serious concern, and may lead to significant morbidity, graft loss, and death of the patient. Acute graft rejection in pediatric recipients is first treated with methylprednisolone pulses, followed by progressive taper of corticosteroid doses. After control of the rejection episode, baseline immunosuppression has to be adjusted and closely monitored since rejection (especially late episodes, occurring more than 6 months after transplantation) may be due to a lack of compliance or sub-therapeutic drug concentrations. The management of corticosteroid resistant rejection is not standardized, and depends on the transplanted organ and previous immunosuppressive regimen. In patients experiencing corticosteroid resistant acute rejection while on a cyclosporine-based immunosuppressive regimen, cyclosporine is generally changed to tacrolimus. In case of tacrolimus-based immunosuppression, tacrolimus blood levels may be increased, and/or mycophenolate mofetil (which nowadays tends to replace azathioprine) or sirolimus may be added, although pharmacodynamic data and clinical studies with these agents are still scarce in pediatric recipients. The use of antithymocyte globulins or monoclonal anti-CD3 antibodies, muromonab CD3 (OKT3) is hampered by numerous adverse effects, including a significant risk of over-immunosuppression. These therapies are nowadays indicated in very selected cases. Other treatments such as plasmapheresis and high dose immunoglobulins may be useful in difficult cases. In patients with refractory rejection despite therapeutic escalation, the risks of over-immunosuppression, including opportunistic infections and malignancies (especially the Epstein-Barr virus related post-transplant lymphoproliferative disease) have to be balanced with the consequences of graft loss due to rejection. Detransplantation or retransplantation may, in some instances, be preferable to severe infectious or tumoral complications.

Outcome of reaching end stage renal failure in children under 2 years of age

AIMS

To determine the outcome of children who reach end stage renal failure before the age of 2 years.

METHODS

Using a retrospective questionnaire, 10 years' data were collected from the paediatric nephrology units in Britain and Ireland (1988 to 1997, follow up 1.3-11.5 years).

RESULTS

A total of 192 children were identified; 0.31/million/year. Most had congenital or inherited conditions, and there were more boys. Latterly, half were diagnosed antenatally. Ninety per cent were dialysed initially, most using home peritoneal cyclers, some by haemodialysis through central lines. Five per cent recovered sufficient function to come off dialysis. Most required tube feeding (often gastrostomy) and erythropoietin; some needed growth hormone. A total of 56% received a transplant (2% without prior dialysis) at (medians) 2.6 years and 12.3 kg. The 2 and 10 year survival of first kidneys was 78%. Growth improved following transplantation. Fourteen per cent died because treatment was not started or was withdrawn. Most had particularly complex renal conditions, or additional major non-renal diagnoses. Typically, decisions not to treat were made mutually between clinicians and families. When treatment was continued, 71% survived, and few had serious non-renal conditions. Most attended normal schools, and by 6 years of age, less than 10% still required dialysis. Infants starting treatment under and over 1 month of age fared equally well.

CONCLUSIONS

By school age, most infants treated for end stage renal failure will have a functioning transplant, reasonable growth, and will attend a normal class, regardless of the age at which they commence treatment. Treatment is seldom sustained in children who have serious additional medical conditions. It is reasonable to treat infants with uncomplicated renal failure.

Renal transplant outcomes in adolescents: a report of the North American Pediatric Renal Transplant Cooperative Study

Recipient age at transplant is an important predictor of outcome. The age most commonly associated with increased risk is infancy. An important, but less recognized, age group at high risk is the adolescent. We analyzed the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) database to determine the patient and graft outcomes of adolescents (13-17 yr of age) compared with younger children. The adolescent age group had a similar percentage patient survival rate compared to that of the younger age groups, except for the infants (0-1 yr), who had a dramatic drop-off in the early post-transplant period. Regarding the long-term graft survival for living donor recipients, adolescents had the poorest percentage graft survival compared to the other age groups, including the infants (p < 0.001). Among cadaver donor recipients, the adolescent group had a significantly poorer graft survival than the 2-5 yr and 6-12 yr age groups (p < 0.001). Although the infants had the poorest graft survival (p < 0.001), after the sharp drop-off in the immediate post-transplant period the slope of their graft-survival curve was similar to that of the 13-17 yr age group. The percentage of late acute rejection episodes among the 6-12 yr (26.0%) and 13-17 yr (22.2%) age groups was significantly higher than in the younger age groups (p < 0.001). The adolescents had relatively poor rejection reversal outcomes compared to the other age groups, with fewer complete rejection reversals and a greater number of partial reversals (p < 0.001). The increased risk of graft loss, late acute rejection, and incomplete rejection reversal observed in the adolescent age group demands further investigation. Lack of compliance with immunosuppression regimens may be an important contributory factor. Strategies to address the unique concerns of this high-risk population will be essential to improve outcomes.

Immunosuppressive therapy for paediatric transplant patients: pharmacokinetic considerations

Immunosuppressive therapy in paediatric transplant recipients is changing as a consequence of the increasing number of available immunosuppressive agents. Generic and other new formulations are now emerging onto the market, clinical experience is growing, and it is expected that clinicians should tailor immunosuppressive protocols to individual patients by optimising dosages and drugs according to the maturation and clinical status of the child. Most information about the clinical pharmacokinetics of immunosuppressive drugs in paediatrics is centred on cyclosporin, tacrolimus and mycophenolate mofetil in renal and liver transplant recipients; data regarding other immunosuppressants and transplant types are limited. Although the clinical pharmacokinetics of these drugs in paediatric transplant recipients are still under investigation, it is evident that the pharmacokinetic parameters observed in adults may not be applicable to children, especially in younger age groups. In general, patients younger than 5 years old show higher clearance rates irrespective of the organ transplanted or drug used. Another important factor that frequently affects clearance in this patient population is the post-transplant time. In accordance with these findings, and in contrast with the usual under-dosage in children, the need for higher dosages in younger recipients and during the early post-transplant period seems evident. To achieve the best compromise between prevention of rejection and toxicity, dosage individualisation is required and this can be achieved through therapeutic drug monitoring (TDM). This approach is particularly useful to ensure the cost-effective management of paediatric transplant recipients in whom the pharmacokinetic behaviour, target concentrations for clinical use and optimal dosage strategies of a particular drug may not yet be well defined. Although TDM may be a tool for improving immunosuppressive therapy, there is little information concerning its positive contribution to clinical events, including outcomes, for paediatric patients. Substantial information to support the use of TDM exists for cyclosporin and, to a lesser extent, for tacrolimus, but a diversity of options affects their implementation in the clinical setting. The role of TDM in therapy with mycophenolate mofetil and sirolimus has yet to be defined regarding both methods and clinical indications. Pharmacodynamic monitoring appears more suited to other immunosuppressants such as azathioprine, corticosteroids and monoclonal or polyclonal antibodies. If coupled with pharmacokinetic measurements, such monitoring would allow earlier and more precise optimisation of therapy. Very few population pharmacokinetic studies have been carried out in paediatric transplant patients. This type of study is needed so that techniques such as Bayesian forecasting can be applied to optimise immunosuppressive therapy in paediatric transplant patients.

Pediatric Kidney Transplantation: Growth, Development, and Nursing Implications

The complex issues related to the growth and development of pediatric kidney transplant recipients are explored in this paper. We divide the pediatric population into 3 age groups—toddlers and preschoolers, school age children, and adolescents—and review the literature describing growth and development in kidney transplant recipients and the normal population briefly for each age group. Planning and delivery of nursing care that is based on the implications of growth and development are discussed, and have relevance for all allied healthcare professionals caring for pediatric kidney transplant recipients and their parents. Allied healthcare professionals in adult settings who provide care to recipients who received a transplant before the age of 18 may also benefit from reviewing this article.

Pediatric kidney transplantation: growth, development, and nursing implications

The complex issues related to the growth and development of pediatric kidney transplant recipients are explored in this paper. We divide the pediatric population into 3 age groups--toddlers and preschoolers, school age children, and adolescents--and review the literature describing growth and development in kidney transplant recipients and the normal population briefly for each age group. Planning and delivery of nursing care that is based on the implications of growth and development are discussed, and have relevance for all allied healthcare professionals caring for pediatric kidney transplant recipients and their parents. Allied healthcare professionals in adult settings who provide care to recipients who received a transplant before the age of 18 may also benefit from reviewing this article.

[Terminal and pre-terminal chronic renal insufficiency in newborns in French neonatal intensive care units: survey of the French pediatric nephrologic society of resuscitation and emergency]

OBJECTIVES

The aim of this study was to describe the intensive care unit neonatologists' attitudes about a neonate with terminal or pre-terminal renal failure.

METHODS

A questionnaire was sent to all French neonatal intensive care units. Physicians were asked to describe their attitude about neonatal chronic renal failure (Would you agree with dialysis and graft for these children?). Physicians were also presented with two clinical observations involving neonates with varying degrees of renal insufficiency and a complicating comorbidity, including neurological abnormality or socioeconomic circumstances.

RESULTS

Responses were obtained from 92% of the university neonatal care units. The will to take care of a neonate with end-stage renal failure till the renal graft, varied greatly from a centre to another one. Three (9%) university-teams said they had a strong will to bring the baby from the neonatal period to the time of renal graft. Eleven other centres (32%) did not have any will for accompanying the baby till the renal graft. Eight centres (24%) would be rather favourable to the idea of dialysis and graft, and 12 others (35%) would be rather unfavourable.

CONCLUSION

The results of this study show great differences between French neonatologists when they are faced to newborns with end stage renal failure. Ethical, medical and organisational difficulties are matters of controversy. The epidemiological impact of the perinatal discussion could be a 20% variation of all the renal grafts in children.

Single-center analysis of early recurrence of nephrotic syndrome following renal transplantation in children

Recurrence of nephrotic syndrome (NS) after transplantation (Tx) occurs in 20-50% of renal transplant recipients, with a median time to recurrence of 14 days and a 50% rate of graft loss. We performed a retrospective analysis of 22 pediatric patients with NS who received renal transplants at the Children's Hospital, Boston, between 1982 and 1999. During the first 14 days following Tx, 13 (59%) patients developed clinical recurrent nephrotic syndrome (RNS). RNS developed in 50% of living donor recipients and in 70% of cadaveric donor recipients (p= non-significant). Seven of the 13 patients with RNS were treated with plasmapheresis, while six received standard immunosuppressive induction therapy only. Two of the seven treated patients and one of the six untreated patients lost their grafts to RNS, yielding a total RNS graft loss rate of 23%. However, patients with RNS who achieved remission had significantly higher cumulative graft survival at 5 yr than did RNS patients who did not achieve remission (p< 0.001). Overall cumulative graft survival at 5 yr was not significantly different between the two groups: 67% in those with non-recurrent nephrotic syndrome (NRNS) vs. 64% in those with RNS, p= non-significant. We conclude that successful reversal of early RNS improves long-term graft survival in pediatric RNS. Multi-center studies are sorely needed to develop novel, less toxic therapies for native and recurrent NS.

Building the Evidence in Peritoneal Dialysis: Use of Randomized Controlled Trials, and Observational and Registry Data

Renal replacement therapy (RRT) has achieved widespread acceptance without being subjected to the rigors of randomized controlled clinical trials (RCCTs). The RCCT remains the “gold standard” of evidenced-based medicine, but ethical, logistic, and financial limitations mean that not all questions are amenable to a RCCT.

Renal registries collect, aggregate, analyze, and interpret data on the occurrence and outcome of renal failure in a defined population. Observational data can be used only to show associations, not causality. Nevertheless, most clinical practice guidelines in nephrology are derived from observational data.

The nephrology community needs to join forces to decide the questions that deserve the time, energy, and resources of an RCCT. Prospective observational data can be enhanced by collaboration, standardized definitions, development of a risk-adjustment tool, and consensus among the key players, including professional associations, government, industry, and hospitals. The challenge is to provide evidence-based practice guidelines for the delivery of care to the end-stage renal patient.

Rejection profile of recent pediatric renal transplant recipients compared with historical controls: a report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS)

Historically, higher acute rejection rates, earlier first rejection, and an inability to reverse the rejection characterize pediatric renal transplantation. In recent years, short-term (1-year) graft survival of pediatric renal transplants has steadily improved. To test the hypothesis that these improvements were mediated by changes in acute rejection, we considered the rejection profile of patients who received a renal allograft between 1987 and 1989 (cohort A) and compared it with recipients transplanted between 1997 and 1999 (Cohort B). Cohort A comprised 1469 transplants and cohort B comprised 1189 transplants. Restricting the data to the first year of follow-up, rejection ratios were 1.6 and 0.7, respectively (p < 0.001). Sixty per cent of the later cohort (B) were rejection free at 1 year, compared with 29% for the earlier cohort (A) (p < 0.001). Controlling for donor source, the rejection reversal rate for the later cohort was significantly better than that of the early cohort (p < 0.001). Cumulative distribution of times to first rejection was significantly better for cohort B (p < 0.001). One-year graft survival for cohort B at 94% was significantly better than 80% for cohort A (p < 0.001). We conclude that the improved short-term graft survival is mediated by improvements in the rejection profile in more recently transplanted patients and that this may translate into a better half-life for pediatric renal transplant recipients who received an allograft in the years 1997-99.