Current management of symptomatic vesicoureteral reflux in pediatric kidney transplantation-A European survey among surgical transplant professionals.

BACKGROUND: Vesicoureteral reflux (VUR) is common in children and adolescents undergoing kidney transplantation (KTx) and may adversely affect allograft kidney function. METHODS: To explore the current management of symptomatic native and allograft VUR in pediatric KTx recipients, an online survey was distributed to European surgical transplant professionals. RESULTS: Surgeons from 40 pediatric KTx centers in 18 countries participated in this survey. Symptomatic native kidney VUR was treated before or during KTx by 68% of the centers (all/selected patients: 33%/67%; before/during KTx: 89%/11%), with a preference for endoscopic treatment (59%). At KTx, 90% favored an anti-reflux ureteral reimplantation procedure (extravesical/transvesical approach: 92%/8%; preferred extravesical technique: Lich-Gregoir [85%]). Management strategies for symptomatic allograft VUR included surgical repair (90%), continuous antibiotic prophylaxis (51%), bladder training (49%), or noninterventional surveillance (21%). Redo ureteral implantation and endoscopic intervention for allograft VUR were equally reported (51%/49%). CONCLUSIONS: This survey shows uniformity in some surgical aspects of the pediatric KTx procedure. However, with regard to VUR, there is a significant variation in practice patterns that need to be addressed by future well-designed and prospective studies. In this way, more robust data could be translated into consensus guidelines for a more standardized and evidence-based management of this common condition in pediatric KTx.

Over Three Decades of Growth Hormone Treatment in Children With Chronic Kidney Disease-Associated Growth Failure Before and After Kidney Transplantation.

BACKGROUND: Growth retardation and short final height is a common complication of chronic kidney disease (CKD) beginning in childhood, with profound deleterious effects on quality of life, mental health, and social achievement. Despite optimal treatments of causative factors for growth retardation in children with CKD, more than 50% of patients reach end-stage renal failure with a height >2 SD below the mean, and most do not demonstrate "catch-up" growth after receiving a kidney transplant. Four decades ago, recombinant human growth hormone (rhGH) treatment was introduced after studies showed increased growth velocity and improved height SDS in uremic subjects. Since then, an abundance of published data showed significant improvements in health-related quality of life, and most studies revealed no significant adverse effects. Clinical practice guidelines recommended rhGH treatment in CKD Stages 3-5D and after transplantation. Despite these guidelines, this therapy remained underutilized. Most commonly cited barriers to the implementation of rhGH treatment were the need for daily injections, financial challenges, physicians' unfamiliarity with guidelines, and fear of adverse events. CONCLUSIONS: rhGH has been shown to improve growth and final height in short children with CKD, with minimal adverse effects. Despite data of its successful use generated over 3 decades, this treatment is underutilized. More judicious utilization of the treatment should emphasize educating patients, their care givers, and members of the multidisciplinary treating team. Additional studies are needed to assess the longer-term rhGH treatment in larger cohorts of patients, leading to additional supportive data and clearer recommendations.

Utilization of donor-derived Cell-Free DNA in pediatric kidney transplant recipients: A single center study.

High donor-derived cell-free DNA (dd-cfDNA) levels indicate transplant allograft injury and can identify graft rejection in kidney transplant recipients. Here, we evaluated the use of dd-cfDNA in pediatric kidney transplant rejection monitoring and treatment. METHODS: Forty-two pediatric kidney transplant patients were enrolled between February 2020 and August 2021. Dd-cfDNA was tested before and after biopsy/rejection treatment. There was a total of 61 allograft biopsies (44 for-cause, 17 surveillance). RESULTS: Graft rejection was found in 35/61 biopsies. Rejection was more common in basiliximab induction compared to rATG (77.1% vs. 22.9%, p = .0121). Median dd-cfDNA was higher in those with rejection (1.2% [0.34-3.12] vs. 0.24% [0.08-0.78], p < .0001). Dd-cfDNA was highest in biopsies with AMR and mixed AMR/TCMR. In addition, dd-cfDNA in basiliximab induction was higher compared to rATG (0.92% [0.27-1.8] vs. 0.26% [0.08-2], p = .0437). Median change in dd-cfDNA after rejection treatment was -0.57% (-1.67 to 0.05). Median time to dd-cfDNA <1% post-rejection treatment was 8.5 days (3.0-19.5). Dd-cfDNA in AMR was higher compared to TCMR or mixed rejection, and levels remained higher in AMR after treatment. In surveillance biopsies, 4/17 had rejection. Median dd-cfDNA was not different in those with versus without rejection (0.48% vs. 0.28%, p = .2342). Those without rejection all had dd-cfDNA <1%. In those with rejection, only one patient had dd-cfDNA >1%, and all had TCMR. CONCLUSIONS: Our findings support dd-cfDNA as a useful indicator of graft rejection and response to treatment. Additional studies are needed to determine the role of dd-cfDNA in graft health surveillance.

BK polyomavirus DNAemia, allograft rejection, and de novo donor-specific antibodies after lowering target tacrolimus levels in pediatric kidney transplant recipients.

BACKGROUND: BK polyomavirus (BKV) DNAemia is a challenging infectious complication after kidney transplant (KT). Reduction of immunosuppression is the mainstay of management, and tacrolimus is often the first immunosuppressive medication adjusted upon the diagnosis of BKV DNAemia. This study aimed to evaluate the impact of a new institutional protocol with lower target tacrolimus levels on BKV DNAemia, allograft rejection, and de novo donor-specific antibodies (dnDSA) among pediatric KT recipients. METHODS: We conducted a retrospective chart review of all KT episodes between January 2013 and December 2018. The new protocol with lower target tacrolimus levels was implemented in March 2015. One hundred twenty-seven patients were included in primary analysis. All patients received induction with basiliximab and methylprednisolone and were maintained on a steroid-based immunosuppressive regimen. RESULTS: In the post-intervention cohort, cumulative incidence of BKV DNAemia at 100 days (13.4% vs. 17.8%, p = .605) and 18 months post-KT (34.1% vs. 26.7%, p = .504) was not significantly different from the pre-intervention cohort. Biopsy-proven rejection rate did not change. However, we observed a trend toward earlier development of dnDSA in the post-intervention cohort using the Kaplan-Meier survival analysis (log-rank p = .06). Younger recipient age at the time of transplant was found to slightly increase the risk of BKV DNAemia (OR: 1.09, 95% CI [1.01, 1.16], p = .024). There was an association between BKV DNAemia and biopsy-proven rejection of any type (adjustedOR: 2.77, 95% CI [1.26, 6.23], p = .012), especially acute T-cell-mediated rejection grade 1A and above (adjustedOR: 2.95, 95% CI [1.06, 8.30], p = .037), after adjusted for recipient age at the time of transplant. CONCLUSIONS: Targeting lower tacrolimus levels did not decrease the incidence of BKV DNAemia within 100 days or 18 months post-KT, nor did it increase the risk of biopsy-proven rejection among pediatric KT recipients in our center. However, there was a trend toward earlier development of dnDSA, which may portend worse long-term graft outcome post-KT. Our findings highlight the need for individualized immunosuppressive regimens based on immunologic and infectious risk factors and the importance of implementing innovative biomarkers to guide therapy and improve outcomes.

Anesthesia and intensive care unit care in pediatric kidney transplantation: An international survey.

BACKGROUND: Despite the high perioperative risk profile, international guidelines for anesthesia and intensive care unit (ICU) care in pediatric kidney transplantation do not exist. Optimizing hemodynamics can be challenging in these patients, while scientific data to guide decisions in hemodynamic monitoring, hemodynamic targets, and perioperative fluid management are lacking. The limited annual number of pediatric kidney transplantations, even in reference centers, necessitates the urge for international collaboration to share knowledge and develop research and guidelines. The aim of this study was to collect data on current perioperative anesthesia and ICU care practices in pediatric kidney transplantation. METHODS: An international survey with an anonymized link was sent from a validated electronic data capture system (Castor). Inclusion criteria were: medical doctor in anesthesia, (ICU), or pediatric nephrology working in a pediatric kidney transplantation specialized center; and signed informed consent. Data were analyzed using descriptive statistics. RESULTS: Thirty-three records were analyzed. Responders were anesthesiologists (58%), pediatric nephrologists (30%), and pediatric intensivists (12%), representing 13 countries worldwide. About half of the centers (48%) performed more than 10 pediatric kidney transplantations a year. Perioperative hemodynamic support was guided by intra-arterial blood pressure (88%), central venous pressure (CVP; 88%), and cardiac output (CO; 39%). The most variation was seen in the hemodynamic targets CVP and CO, fluid administration, and inotrope/vasopressor use. The protocolized use of furosemide (46%) and mannitol (61%) also varied between centers. Postoperative care for the youngest recipients occurred in the pediatric intensive care unit at all centers. CONCLUSION: The results of this survey reveal a large variation in anesthesia and ICU care in pediatric kidney transplantation centers worldwide, particularly in CVP and CO targets, hemodynamic therapy, and the use of furosemide and mannitol. These data identify areas for further research and can be a starting point for international research collaboration and guideline development.

Limited Sampling Strategies to Predict Ganciclovir Exposure after Valganciclovir Administration and to Reduce Monitoring Constraints in Renal Transplant Children.

Valganciclovir, the ganciclovir prodrug, is an antiviral agent used to prevent cytomegalovirus infection in renal transplant children. Therapeutic drug monitoring is still necessary to ensure optimal therapeutic area under the concentration-time curve from 0 to 24 h (AUC0-24) of 40 to 60 µg·h/mL since valganciclovir presents a high pharmacokinetic variability. To calculate ganciclovir AUC0-24 with the trapezoidal method, 7 samples are needed. The objective of this study was to develop and validate a reliable and clinically applicable limited sampling strategy (LSS) for individualizing valganciclovir dose in renal transplant children. Rich pharmacokinetic data from ganciclovir plasmatic dosages measured in renal transplant children who received valganciclovir to prevent cytomegalovirus infection at Robert Debré University Hospital were collected retrospectively. Ganciclovir AUC0-24s were calculated using the trapezoidal method. The LSS was developed using a multilinear regression approach to predict AUC0-24. The patients included were divided into two groups for model development (50 patients) and validation (30 patients). A total of 80 patients were included between February 2005 and November 2018. Multilinear regression models were developed on 50 pharmacokinetic profiles (50 patients) and validated with an independent group of 43 pharmacokinetic profiles (30 patients). Regressions based on samples collected at T1h-T4h-T8h, T2h-T4h-T8h, or T1h-T2h-T8h presented the best AUC0-24 predictive performances with an average difference between reference and predicted AUC0-24 of -0.27, 0.34, and -0.40 µg·h/mL, respectively. In conclusion, valganciclovir dosage adaptation was required in children to achieve the target AUC0-24. Three LSS models using three pharmacokinetic blood samples instead of seven will be useful for individualizing valganciclovir prophylaxis in renal transplant children.

Use of organs from increased infectious risk deceased donors in pediatric kidney transplantation.

Living donors are the main source of transplanted kidneys for children and young people in many countries, but there still remains a significant need for deceased donor kidney transplantation. Given the waiting times associated with deceased donor kidney transplantation and the morbidity or mortality that can occur in those on the waiting list, it is essential that the utilization of kidneys from deceased donors is optimized. The use of organs from deceased donors at increased risk of transmitting human immunodeficiency virus, hepatitis B virus, or hepatitis C virus is relatively common in adults, but far less so in children. The risks and benefits of the use of kidneys from increased infectious risk donors (IIRD) are discussed. The variation of definitions of IIRD between countries is explored as is the need for pediatric nephrologists and transplant surgeons to have an understanding of the prevalence of viral diseases within the country in which they work. The role of screening tests such as nucleic acid tests is examined, along with the concept of residual risk. Finally, considerations in acquiring informed consent in the use of kidneys from IIRDs in children and young people are discussed.

Fibroblast growth factor 23-Klotho and mineral metabolism in the first year after pediatric kidney transplantation: A single-center prospective study.

BACKGROUND: The role of fibroblast growth factor 23 (FGF23) levels in mineral metabolism before and after kidney transplantation in pediatric patients is poorly understood. METHODS: We prospectively evaluated 24 patients under 18 years of age (4.5 [3.3-9.8] years) who underwent living kidney transplantation between July 2016 and March 2018, and measured intact FGF23 and serum αKlotho levels, and other parameters of mineral metabolism before and after transplantation (Day 7, 1 and 4 months, and 1 year). Relationships between parameters were examined by linear analysis. RESULTS: FGF23 level was 440.8 [63.4-5916.3] pg/ml pre-transplant and decreased significantly to 37.1 [16.0-71.5] pg/ml at Day 7 post-transplant (-91.6%, p < .001). Thereafter, it remained at normal levels until 1 year. αKlotho level was 785 [568-1292] pg/ml pre-transplant and remained low at Day 7 and 1 month post-transplant, with an increasing trend at 4 months. Post-transplant phosphorus levels were significantly decreased compared with pre-transplant, with a lowest level of 1.7 [1.3-2.9] mg/dl, -5.7 [-6.8, -3.8] SD at Day 4, followed by gradual recovery. Phosphorus levels and the ratio of tubular maximum phosphate reabsorption were significantly and negatively associated with pre-transplant FGF23 until 4 months of post-transplant. Pre-transplant αKlotho was negatively associated with pre-transplant FGF23 but not FGF23 or other parameters after transplantation. CONCLUSION: FGF23 in pediatric kidney transplant patients decreased rapidly after transplantation and associated with post-transplant hypophosphatemia and increased phosphorus excretion. Post-transplant αKlotho was low early post-transplant but tended to increase subsequently. Post-transplant αKlotho was unaffected by pre-transplant FGF23 or other factors, suggesting pre-transplant chronic kidney disease status has no effect.

Systematic use of magnetic double J stent in pediatric kidney transplantation: A single-center experience.

BACKGROUND: The intraoperative insertion of a double J stent (DJS) is known to reduce urological complications and is broadly accepted in kidney transplant (KTx) patients. The magnetic ureteral DJS (mDJS) represents a valid alternative device as it can be removed without cystoscopy, using a transurethral magnet. This is of particular importance in the pediatrics, allowing us to avoid cystoscopy requiring general anesthesia (GA) in this population. To date, few data are available on the systematic use of mDJS in pediatric patients undergoing KTx. METHODS: We report a retrospective analysis of 32 consecutive pediatric KTx at our center from July 2020 to December 2021. RESULTS: Ureteral stents remained in place for a median of 35 days (range: 12-76). Non-surgical magnetic removal of the mDJS was attempted in all cases without complications. In most cases (69%), the removal procedure was performed in an outpatient clinic. In 10 cases, the mDJS was removed in the operating room under sedation before removal of the abdominal Tenckhoff catheter. All patients were clinically followed (range: 3-15 months). CONCLUSIONS: We confirm the safety and feasibility of systematic use of mDJS in the setting of pediatric KTx. The systematic use of this device contributes to reduce the need for GA and the rate of hospital admission.

Diagnostic and therapeutic management of vesico-ureteral reflux in pediatric kidney transplantation-Results of an online survey on behalf of the European Society for Paediatric Nephrology.

BACKGROUND: Vesico-ureteral reflux (VUR) is considered to be a risk factor for recurrent febrile urinary tract infections and impaired renal transplant survival. METHODS: An online survey supported by the European Society for Paediatric Nephrology was designed to evaluate current management strategies of VUR in native and transplanted kidneys of recipients aged <18 years. RESULTS: Seventy-three pediatric transplant centers from 32 countries contributed to the survey. All centers performed urological evaluation prior to pediatric kidney transplantation (KTx) with subsequent interdisciplinary discussion. Screening for VUR in native kidneys (30% in all, 70% in selected patients) led to surgical intervention in 78% (11% in all, 89% in selected patients) with a decided preference of endoscopic intervention over ureterocystoneostomy. Following KTx, continuous antibiotic prophylaxis was applied in 65% of the patients and screening for allograft VUR performed in 93% of selected patients. The main management strategies of symptomatic allograft VUR were continuous antibiotic prophylaxis (83%) and surgical treatment (74%) (endoscopic intervention 55%, redo ureterocystoneostomy 26%). CONCLUSIONS: This survey demonstrates the high variability in the management of VUR in pediatric KTx recipients, points to knowledge gaps, and might serve as a starting point for improving the care for patients with VUR in native and transplanted kidneys.

Emulation of the control cohort of a randomized controlled trial in pediatric kidney transplantation with Real-World Data from the CERTAIN Registry.

BACKGROUND: Randomized controlled trials in pediatric kidney transplantation are hampered by low incidence and prevalence of kidney failure in children. Real-World Data from patient registries could facilitate the conduct of clinical trials by substituting a control cohort. However, the emulation of a control cohort by registry data in pediatric kidney transplantation has not been investigated so far. METHODS: In this multicenter comparative analysis, we emulated the control cohort (n = 54) of an RCT in pediatric kidney transplant patients (CRADLE trial; ClinicalTrials.gov NCT01544491) with data derived from the Cooperative European Paediatric Renal Transplant Initiative (CERTAIN) registry, using the same inclusion and exclusion criteria (CERTAIN cohort, n = 554). RESULTS: Most baseline patient and transplant characteristics were well comparable between both cohorts. At year 1 posttransplant, a composite efficacy failure end point comprising biopsy-proven acute rejection, graft loss or death (5.8% ± 3.3% vs. 7.5% ± 1.1%, P = 0.33), and kidney function (72.5 ± 24.9 vs. 77.3 ± 24.2 mL/min/1.73 m2 P = 0.19) did not differ significantly between CRADLE and CERTAIN. Furthermore, the incidence and severity of BPAR (5.6% vs. 7.8%), the degree of proteinuria (20.2 ± 13.9 vs. 30.6 ± 58.4 g/mol, P = 0.15), and the key safety parameters such as occurrence of urinary tract infections (24.1% vs. 15.5%, P = 0.10) were well comparable. CONCLUSIONS: In conclusion, usage of Real-World Data from patient registries such as CERTAIN to emulate the control cohort of an RCT is feasible and could facilitate the conduct of clinical trials in pediatric kidney transplantation. A higher resolution version of the Graphical abstract is available as Supplementary information.

Precise clinicopathologic findings for application of genetic testing in pediatric kidney transplant recipients with focal segmental glomerulosclerosis/steroid-resistant nephrotic syndrome.

BACKGROUND: Establishing a molecular genetic diagnosis of focal segmental glomerulosclerosis (FSGS)/steroid-resistant nephrotic syndrome (SRNS) can be useful for predicting post-transplant recurrence. Monogenic causes are reportedly present in approximately 20-30% of patients with FSGS/SRNS. However, the characteristics of patients who are likely to have a monogenic cause remain to be determined. METHODS: Pediatric recipients with SRNS and/or biopsy-proven FSGS who underwent their first kidney transplantation at our center between 1999 and 2019 were analyzed. Patients with secondary FSGS/SRNS were excluded. The recipients were divided into three groups: familial/syndromic, presumed primary, and undetermined FSGS/SRNS. Patients who met all of the following criteria were categorized as having presumed primary FSGS/SRNS: (i) nephrotic syndrome, (ii) complete or partial remission with initial steroid therapy and/or additional immunosuppressive therapies, and (iii) diffuse foot process effacement on electron microscopy in the native kidney biopsy. All patients underwent genetic testing using next-generation sequencing. RESULTS: Twenty-four patients from 23 families were analyzed in this study. Pathogenic or likely pathogenic variants in FSGS/SRNS-related genes were identified in four of four families, zero of eight families, and 10 of 11 families with familial/syndromic, presumed primary, and undetermined FSGS/SRNS, respectively. Post-transplant recurrence only occurred in patients with presumed primary FSGS/SRNS. CONCLUSIONS: Our systematic approach based on precise clinicopathological findings including nephrotic syndrome, treatment responses, and diffuse foot process effacement might be useful to differentiate pediatric kidney transplant recipients with FSGS/SRNS who are likely to have a monogenic cause from patients who are not, and to predict post-transplant recurrence. A higher resolution version of the Graphical abstract is available as Supplementary information.

Transplantation Mediates Much of the Racial Disparity in Survival from Childhood-Onset Kidney Failure.

BACKGROUND: The role of kidney transplantation in differential survival in Black and White patients with childhood-onset kidney failure is unexplored. METHODS: We analyzed 30-year cohort data of children beginning RRT before 18 years of age between January 1980 and December 2017 (n=28,337) in the US Renal Data System. Cox regression identified transplant factors associated with survival by race. The survival mediational g-formula estimated the excess mortality among Black patients that could be eliminated if an intervention equalized their time with a transplant to that of White patients. RESULTS: Black children comprised 24% of the cohort and their crude 30-year survival was 39% compared with 57% for White children (log rank P<0.001). Black children had 45% higher risk of death (adjusted hazard ratio [aHR], 1.45; 95% confidence interval [95% CI], 1.36 to 1.54), 31% lower incidence of first transplant (aHR, 0.69; 95% CI, 0.67 to 0.72), and 39% lower incidence of second transplant (aHR, 0.61; 95% CI, 0.57 to 0.65). Children and young adults are likely to require multiple transplants, yet even after their first transplant, Black patients had 11% fewer total transplants (adjusted incidence rate ratio [aIRR], 0.89; 95% CI, 0.86 to 0.92). In Black patients, grafts failed earlier after first and second transplants. Overall, Black patients spent 24% less of their RRT time with a transplant than did White patients (aIRR, 0.76; 95% CI, 0.74 to 0.78). Transplantation compared with dialysis strongly protected against death (aHR, 0.28; 95% CI, 0.16 to 0.48) by time-varying analysis. Mediation analyses estimated that equalizing transplant duration could prevent 35% (P<0.001) of excess deaths in Black patients. CONCLUSIONS: Equalizing time with a functioning transplant for Black patients may equalize survival of childhood-onset ESKD with White patients.

Findings from 4C-T Study demonstrate an increased cardiovascular burden in girls with end stage kidney disease and kidney transplantation.

Mortality in children with kidney failure is higher in girls than boys with cardiovascular complications representing the most common causes of death. Pulse wave velocity (PWV), a measure of vascular stiffness, predicts cardiovascular mortality in adults. Here, PWV in children with kidney failure undergoing kidney replacement therapy was investigated to determine sex differences and potential contributing factors. Two-hundred thirty-five children (80 girls; 34%) undergoing transplantation (150 pre-emptive, 85 with prior dialysis) having at least one PWV measurement pre- and/or post-transplantation from a prospective cohort were analyzed. Longitudinal analyses (median/maximum follow-up time of 6/9 years) were performed for PWV z-scores (PWVz) using linear mixed regression models and further stratified by the categories of time: pre-kidney replacement therapy and post-transplantation. PWVz significantly increased by 0.094 per year and was significantly higher in girls (PWVz +0.295) compared to boys, independent of the underlying kidney disease. During pre-kidney replacement therapy, an average estimated GFR decline of 4 ml/min/1.73 m2 per year was associated with a PWVz increase of 0.16 in girls only. Higher diastolic blood pressure and low density lipoprotein were independently associated with higher PWVz during pre-kidney replacement therapy in both sexes. In girls post-transplantation, an estimated GFR decline of 4ml/min/1.73m2 per year pre-kidney replacement therapy and a longer time (over 12 months) to transplantation were significantly associated with higher PWVz of 0.22 and of 0.57, respectively. PWVz increased further after transplantation and was positively associated with time on dialysis and diastolic blood pressure in both sexes. Thus, our findings demonstrate that girls with advanced chronic kidney disease are more susceptible to develop vascular stiffening compared to boys, this difference persist after transplantation and might contribute to higher mortality rates seen in girls with kidney failure.

Antibody-mediated rejection after kidney transplantation in children; therapy challenges and future potential treatments.

Antibody-mediated rejection (AMR) remains one of the most critical problems in renal transplantation, with a significant impact on patient and graft survival. In the United States, no treatment has received FDA approval jet. Studies about treatments of AMR remain controversial, limited by the absence of a gold standard and the difficulty in creating large, multi-center studies. These limitations emerge even more in pediatric transplantation because of the limited number of pediatric studies and the occasional use of some therapies with unknown and poorly documented side effects. The lack of recommendations and the unsharp definition of different forms of AMR contribute to the challenging management of the therapy by pediatric nephrologists. In an attempt to help clinicians involved in the care of renal transplanted children affected by an AMR, we rely on the latest recommendations of the Transplantation Society (TTS) for the classification and treatment of AMR to describe treatments available today and potential new treatments with a particular focus on the pediatric population.

My Kidney Identity: Contextualizing pediatric patients and their families kidney transplant journeys.

BACKGROUND: Even though having a kidney transplant is the treatment of choice for children with kidney failure, it can cause anxiety for patients and their families resulting in decreased psychosocial functioning, adherence, and self-management. We set out to identify the information needs required to help pediatric patients and their families contextualize their posttransplant experiences as they recalibrate their understanding of normalcy throughout their transplant journey. METHODS: Participants submitted photographs related to feeling: (1) worried, (2) confident, (3) similar to peers without kidney disease, and (4) different from these peers. The photographs served as a foundation for an in-depth interview. RESULTS: Nineteen individuals (10 pediatric transplant recipients and 9 caregivers) were interviewed at a mean of 8 years posttransplant. We identified five specific themes and tensions our participants associated with recalibrating their version of "normal" throughout the transplant journey: (1) exchanging information (information consumers vs. information contributors, (2) transitional management (family management vs. self-management), (3) building confidence (worry vs. confidence), (4) telling one's story (hiding vs. self-expression), and (5) normalizing kidney transplantation (feeling different vs. feeling similar). These five themes/tensions form one's Kidney Identity, shift from negative to positive throughout the transplant journey, illustrating a more abstract and complex account of kidney transplantation over time. CONCLUSIONS: Having a patient view their Kidney Identity over time may support self-reflection of one's progress posttransplant and potentially help clinicians, patients, and their caregivers identify barriers and areas where they may need more support to ensure their successful engagement in their care.

Maternal versus paternal living kidney transplant donation is associated with lower rejection in young pediatric recipients: A Collaborative Transplant Study report.

BACKGROUND: Approximately 1700 children per year with end-stage kidney disease undergo kidney transplantation in Europe and the United States of America; 30%-50% are living donor kidney transplantations. There may be immunological differences between paternal and maternal donors due to transplacental exchange of cells between the mother and fetus during pregnancy leading to microchimerism. We investigated whether the outcome of living-related kidney transplantation in young children is different after maternal compared with paternal organ donation. METHODS: Using the international Collaborative Transplant Study (CTS) database, we analyzed epidemiological data of 7247 children and adolescents aged <18 years who had received a kidney transplant from either mother or father. Risk of treated rejection episodes and death-censored graft failure were computed using the Kaplan-Meier method and multivariable Cox regression. RESULTS: In the recipient age group 1-4 years, the rate of treated rejection episodes in recipients of kidneys from maternal donors (N = 195) during the first 2 years post-transplant was significantly lower (hazard ratio HR = 0.47, p = .004) than in patients receiving kidneys from paternal donors (N = 179). This association between donor sex and risk of treated rejections was not observed in children aged 5-9 years. The 5-year death-censored graft survival in children aged 1-4 years with a maternal or paternal donor was comparable. CONCLUSIONS: Maternal kidney donation in young pediatric renal transplant recipients is associated with an approximately 50% lower rate of treated rejection than paternal kidney donation. Whether this phenomenon is due to maternal microchimerism-induced donor-specific hyporesponsiveness must be evaluated in prospective mechanistic studies.

Timing of reconstruction of the lower urinary tract in pediatric kidney transplant recipients: A CERTAIN multicenter analysis of current practice.

BACKGROUND: Preexistent LUTD are considered a hostile environment, which might negatively impact KTx survival. In such cases, surgical reconstruction of the bladder is required. However, there is still disagreement on the optimal timing of the reconstruction procedure. METHODS: This is a multicenter analysis of data from the CERTAIN Registry. Included were 62 children aged 8.18 ± 4.90 years, with LUTD. Study endpoints were the duration of initial posttransplant hospitalization, febrile UTIs, and a composite failure endpoint comprising decline of eGFR, graft loss, or death up to 5 years posttransplant. Outcome was compared to matched controls without bladder dysfunction. RESULTS: Forty-one patients (66.1%) underwent pretransplant and 14 patients (22.6%) posttransplant reconstruction. Bladder augmentation was performed more frequently in the pretransplant (61%) than in the posttransplant group (21%, p = .013). Outcome in the pre- and posttransplant groups and in the subgroups of patients on pretransplant PD with major bladder surgery either pre- (n = 14) or posttransplant (n = 7) was comparable. Outcomes of the main study cohort and the matched control cohort (n = 119) were comparable during the first 4 years posttransplant; at year 5, there were more events of transplant dysfunction in the study cohort with LUTD than in controls (p = .03). CONCLUSIONS: This multicenter analysis of the current practice of LUTD reconstruction in pediatric KTx recipients shows that pre- or posttransplant surgical reconstruction of the lower urinary tract is associated with a comparable 5-year outcome.

Prevalence and potential relevance of hyperuricemia in pediatric kidney transplant recipients-a CERTAIN registry analysis.

BACKGROUND: Asymptomatic hyperuricemia is frequently observed in pediatric kidney transplant recipients; symptomatic hyperuricemia, however, is a rare complication. Only few data are available in this patient population. We, therefore, investigated the prevalence of hyperuricemia and its association with kidney transplant function and blood pressure in a multicenter cohort of pediatric kidney transplant recipients. METHODS: This is a retrospective, observational multicenter registry study. All pediatric kidney transplant recipients in the CERTAIN database with at least one documented serum uric acid level and a follow-up of 5 years posttransplant were eligible. We identified 151 patients with 395 measurements of serum uric acid. We calculated the prevalence of hyperuricemia, analyzed potential risk factors and clinical consequences such as elevated blood pressure and reduced estimated glomerular filtration rate (eGFR). Statistical analysis was performed using IBM SPSS Statistics 26. RESULTS: One hundred and ten of 395 (27.8%) serum uric acid levels were above 416 µmol/L (7.0 mg/dL), defined as the upper limit of normal. Univariate analysis showed a significant (p = .026) inverse association of serum uric acid with eGFR overtime. There was no significant association of serum uric acid concentrations with body mass index (z-score), blood pressure (z-score), or sex. No episodes of gout were documented. CONCLUSION: This study shows that hyperuricemia is present in a considerable number of patients sometime after pediatric kidney transplantation and is associated with lower eGFR. Whether hyperuricemia contributes to faster decline of graft function or to the overall cardiovascular risk of these patients remains to be elucidated.

Publication rate and research topics of studies in pediatric kidney transplantation.

BACKGROUND: The quality of medical care for pediatric kidney transplant recipients depends on sound evidence from published clinical trials. METHODS: We examined the publication rate, time to publication, and factors associated with publication of studies in pediatric kidney transplantation registered on ClinicalTrials.gov from 1999 to 2020. RESULTS: We identified 136 studies with an overall enrollment of 36255 study participants, of which only 58.8% have been published yet. Unpublished studies included data from 14 350 participants. The median time to publication was 25 months (range, 0-117) with a significantly shorter time to publication in more recent years. The most frequently investigated research topic was immunosuppressants (49.3%), followed by perioperative management (11.0%) and infectiology (10.3%). The percentage of published studies was highest for the topic steroid withdrawal (87.5%), followed by infectiology (78.6%), and nutrition, sports and quality of life (71.4%). Studies, which were co-funded by industry, showed a significantly higher 5-year publication rate (p = 0.019). CONCLUSIONS: In conclusion, nearly half of all studies in pediatric kidney transplantation remain unpublished. Non-publication of studies might lead to a publication bias with a negative impact on clinical decision-making.