Pre-emptive pediatric kidney transplantation or not?

Review - Renal transplantation for congenital urological diseases

INTRODUCTION

Congenital Anomalies of the Kidney and Urinary Tract (CAKUT) are structural disorders originating prenatally and present at birth. Affecting 4.2 to 1000 per 10,000 births globally, CAKUT includes conditions like posterior urethral valves, cloacal anomalies, and reflux nephropathy. These anomalies can lead to chronic kidney disease (CKD) or end-stage kidney disease (ESKD) in children, necessitating renal replacement therapy or transplantation.

OBJECTIVES

This article aims to provide an updated perspective on pediatric kidney transplantation for children with CAKUT, emphasizing pre-transplant evaluation and management to optimize long-term outcomes.

METHODS

A comprehensive urologic evaluation is essential for children with ESKD being considered for kidney transplantation. Key pre-transplant investigations include kidney/bladder ultrasound (US), voiding cystourethrogram (VCUG), uroflowmetry, and urodynamics (UDS)/video-urodynamics (VUDS). Non-operative interventions such as pharmacotherapy and clean intermittent catheterization (CIC) are also considered. Surgical interventions, like augmentation cystoplasty or continent catheterizable channels, are evaluated based on individual patient needs.

RESULTS

Kidney/bladder US and VCUG provide essential anatomical information. UDS offers comprehensive functional data, identifying hostile bladders needing pre-transplant optimization. Non-surgical measures like anticholinergics and CIC improve bladder function, while surgical options enhance compliance and capacity. Concurrent interventions during transplantation are feasible but require careful consideration of risks and benefits.

DISCUSSION

Children with CAKUT undergoing kidney transplantation exhibit comparable or better graft survival rates than those without CAKUT. However, those with lower urinary tract obstructions (LUTO) may have poorer long-term outcomes. UDS is crucial for evaluating bladder function pre-transplant, guiding the need for interventions. Long-term monitoring for urinary tract infections (UTIs) and bladder dysfunction is essential.

CONCLUSION

Optimal outcomes in pediatric kidney transplantation for CAKUT patients require thorough pre-transplant evaluation and management, particularly for those with LUTO. Multidisciplinary approaches ensure careful monitoring and timely interventions, improving graft survival and quality of life for these patients.

Cytopenias in pediatric kidney transplant recipients: preceding factors and clinical consequences

BACKGROUND

Kidney trans plantation is associated with secondary complications, including the risk of developing posttransplant cytopenias. This study aimed to evaluate the characteristics, identify predictors, and assess the management and consequences of cytopenias in the pediatric kidney transplant population.

METHODS

This is a single-center retrospective analysis of 89 pediatric kidney transplant recipients. Possible factors preceding cytopenias were compared with the goal of recognizing predictors for posttransplant cytopenias. Posttransplant neutropenias were analyzed for the total study period and separately for the period beyond 6 months posttransplant (late neutropenias), to rule out confounding influences of induction and initial intensive therapy.

RESULTS

Sixty patients (67%) developed at least one episode of posttransplant cytopenia. All episodes of posttransplant thrombocytopenias were mild or moderate. Posttransplant infections and graft rejection were found to be significant predictors for thrombocytopenia (HR 6.06, 95% CI 1.6-22.9, and HR 5.82, 95% CI 1.27-26.6, respectively). A total of 30% of posttransplant neutropenias were severe (ANC ≤ 500). Pretransplant dialysis and posttransplant infections were significant predictors for late neutropenias (HR 11.2, 95% CI 1.45-86.4, and HR 3.32, 95% CI 1.46-7.57, respectively). Graft rejection occurred in 10% of patients with cytopenia, all following neutropenia, within 3 months from cytopenia appearance. In all such cases, mycophenolate mofetil dosing had been held or reduced prior to rejection.

CONCLUSIONS

Posttransplant infections are substantial contributors to developing posttransplant cytopenias. Preemptive transplantation appears to reduce risk of late neutropenia, the accompanying reduction in immunosuppressive therapy, and the ensuing risk of graft rejection. An alternative response to neutropenia, possibly using granulocyte colony stimulating factor, may diminish graft rejection. A higher resolution version of the Graphical abstract is available as Supplementary information.

Reduced peripheral and respiratory muscle strength in pediatric patients after kidney transplantation

INTRODUCTION

Reduced muscle strength and low-exercise capacity are well documented in adults, but there are few studies examining those impairments in children and adolescents after kidney transplantation. The objective of this study was to evaluate peripheral and respiratory muscle strength and the association with submaximal exercise capacity in children and adolescents after kidney transplant.

METHODS

Forty-seven patients between six and 18 years of age clinically stable after transplantation were included. Peripheral muscle strength (isokinetic and hand-grip dynamometry), respiratory muscle strength (maximal inspiratory and expiratory pressure), and submaximal exercise capacity (six-minute walk test - 6MWT) were assessed.

RESULTS

Patients had a mean age of 13.1 ± 2.7 years and an average of 34 months had elapsed since the transplantation. Flexors of the knee showed a significant reduction in muscle strength (77.3% of predicted) and knee extensors had normal values (105.4% of predicted). Hand-grip strength and maximal respiratory pressures (inspiratory and expiratory) also were significantly lower than expected (p < 0.001). Although distance walked in the 6MWT was significantly lower than predicted (p < 0.001), no significant correlation was found with peripheral and respiratory muscle strength.

CONCLUSION

Children and adolescents after kidney transplantation have reduced peripheral muscle strength of knee flexors, hand-grip, and maximal respiratory pressures. No associations were found between peripheral and respiratory muscle strength and submaximal exercise capacity.

Is Preemptive Kidney Transplantation Associated With Improved Outcomes when Compared to Non-preemptive Kidney Transplantation in Children? A Systematic Review and Meta-Analysis

Main Problem: Preemptive kidney transplantation (PKT) is performed prior to dialysis initiation to avoid dialysis-related morbidity and mortality in children and adolescents. We undertook a systematic review to compare clinical outcomes in PKT versus kidney transplantation after dialysis initiation in paediatric patients.

Methods: The bibliographic search identified studies that compared paediatric recipients of a first or subsequent, living or deceased donor PKT versus non-preemptive kidney transplant. Methodological quality was assessed for all studies. Data were pooled using the random-effects model.

Results: Twenty-two studies (n = 22,622) were included. PKT reduced the risk of overall graft loss (relative risk (RR) .57, 95% CI: .49–.66) and acute rejection (RR: .81, 95% CI: .75–.88) compared to transplantation after dialysis. Although no significant difference was observed in overall patient mortality, the risk of patient death was found to be significantly lower in PKT patients with living donor transplants (RR: .53, 95% CI: .34–.83). No significant difference was observed in the incidence of delayed graft function.

Conclusion: Evidence from observational studies suggests that PKT is associated with a reduction in the risk of acute rejection and graft loss. Efforts should be made to promote and improve rates of PKT in this group of patients (PROSPERO).

Systematic Review Registration:https://clinicaltrials.gov/, CRD42014010565

Acute Rejection Is a Strong Negative Predictor of Graft Survival in Living-Donor Pediatric Renal Transplant: 10-Year Follow-Up in a Single Mexican Center

OBJECTIVES

Kidney transplant is the optimal treatment for children with end-stage renal disease. Multiple factors affect patient and graft survival. We assessed determinants of long-term patient/graft survival in our center by a retrospective review of pediatric living donor (< 18 years) kidney transplants from February 2003 to December 2016.

MATERIALS AND METHODS

Donor and recipient demo-graphic data and immunosuppression use were gathered for analyses. Transplant outcomes included patient/graft survival, acute rejection, and 1-year estimated glomerular filtration rate. Patient/graft survival results were analyzed by Kaplan-Meier, and Cox proportional hazards regression model was used for risk factors (univariate/multivariate). P ≤ .05 was statistically significant.

RESULTS

Ninety-nine patients were included. Age was 13.4 ± 3.08 years, 64.6% were male, and 88.9% were on dialysis with time of 17.1 ± 12.6 months. Mean donor age was 36.6 ± 7.7 years, and most were females (63.6%). Donor estimated glomerular filtration rate was 89.4 ± 16.9 mL/min/1.73 m2. HLA match was 3.2 ± 1.05. Panel reactive antibody showed 8.6 ± 20.5%. Of total patients, 47.5% used induction, 88.9% used cyclo-sporine, and 100% used mycophenolate mofetil. Five- and 10-year patient survival rates were 93.2% and 93.2%. One-year acute rejection was 14.1%, with rate of 24.2% throughout follow-up. One-year estimated glomerular filtration rate was 76.4 ± 25.6 mL/min/1.73 m2. Five- and 10-year graft survival rates were 62.6% and 43.3%. Multivariate analysis confirmed donor age and acute rejection episodes throughout follow-up as risk factors for graft survival (P < .05).

CONCLUSIONS

Acute rejection and donor age are important risk factors for 10-year graft survival in living-donor pediatric kidney transplant in our program.

Renovascular hypertension: results in adulthood of renal autotransplantation performed in children

BACKGROUND

This study describes the long-term results of renal autotransplantation for renovascular hypertension performed in children who are now 21 years of age or older.

METHODS

Sixteen children (4 boys, 12 girls) with a mean age of 11.2 years at the time of the procedure underwent ex-vivo surgery at the university hospital of Saint-Etienne between 1992 and 2008. Acetylsalicylic acid was used for antiplatelet therapy in the postoperative period, without routine anticoagulation. The mean follow-up period was 15 years. The clinical course of these patients was retrospectively reviewed in adulthood and the results analyzed.

RESULTS

The children were treated with a mean of 2.37 drugs per patient, and the mean preoperative blood pressure of the entire patient population was 151/89 mmHg. Mean preoperative creatinine clearance was 80 ml/min/1.73 m². There was no postoperative death. One patient experienced a thrombosis immediately after the surgery, leading to a redo surgery. In this patient diuresis was restarted, but without efficient concentration and filtration, ultimately leading the patient to have a renal transplant after 1 year. At the end of the follow-up period, eight of the 16 patients (50%) were cured and the others were improved. At the last follow-up the mean blood pressure was 127/70 mmHg, and the mean number of drugs per patient was 0.68. The mean creatinine clearance at last follow-up was 104.3 ml/min/1.73 m². Three patients had secondary procedures, with two undergoing percutaneous angioplasty (at postoperative months 9 and 12, respectively) and one having an hepatorenal bypass at postoperative year 4. Primary patency was 12/16 (75%); primary assisted patency was 15/16 (94%); secondary patency was 16/16 (100%).

CONCLUSION

This study shows that renal autotransplantation has good and stable long-term results and is an effective conservative strategy for treating renovascular hypertension in children, thus avoiding nephrectomy.