Special Considerations in Pediatric Kidney Transplantation

Underappreciated Effects of Delayed Graft Function in Pediatric Kidney Transplantation

PURPOSE

In kidney transplantation (KT), delayed graft function (DGF) is associated with worse outcomes. However, it is unclear what effect DGF plays in long-term survival compared to the impact of the various transplant, donor, and recipient risk factors associated with DGF. This study aims to determine the effect of DGF alone on long-term survival in pediatric deceased donor kidney transplant recipients (DDKTRs).

METHODS

Using a national database, 1728 pediatric patients who received a kidney transplant between 1994 and 2009 (n = 978) and 2010 and 2022 (n = 750) were identified. Cases and controls were matched by DGF status for transplant date, cold ischemia time, distance from the transplant center, HLA mismatch level, PRA, KDPI, recipient and donor age, BMI, sex assigned at birth, and ethnicity. Kaplan-Meier curves were analyzed with a log-rank test. Pearson's chi-squared tests were used to compare survival proportions between groups at time benchmarks.

RESULTS

Pediatric DDKTRs with DGF had worse graft (p < 0.001) and patient (p < 0.001) survival compared to non-DGF patients in both eras. Between 1994 and 2009, graft survival rates were lower in the DGF cohort at 1 (p < 0.001), 3 (p < 0.001), 5 (p < 0.001), and 10 years (p = 0.010). Patient survival rates were lower in the DGF cohort at 1 (p = 0.017) and 5 years (p = 0.019) post-DDKT. There was no difference in 3 (p = 0.071) and 10-year patient survival rates (p = 0.141). Between 2010 and 2022, graft and patient survival rates were lower in the DGF cohort at 1, 3, 5, and 10 years (all p < 0.001). There was no difference in rates of retransplantation (p = 0.307 and p = 0.771) between groups for either era.

CONCLUSIONS

DGF alone is associated with worse outcomes in pediatric DDKTRs. DGF should be taken seriously, especially in cases where pediatric DDKTRs do not possess known, attributable risk factors for DGF.

Effect of perioperative management on early graft function in living donor paediatric kidney transplantation

BACKGROUND

Paediatric kidney transplantation has an increased risk of surgical and vascular complications, with intensive care monitoring required postoperatively. This study aimed to determine if perioperative management affects early graft function in living donor paediatric kidney transplantation.

METHODS

Clinical data was extracted from the electronic medical record for living donor kidney transplants at two paediatric centres covering the state of New South Wales (NSW), Australia from 2009 to 2021. Estimated glomerular filtration rate (eGFR) of 7 days and 1-month post-transplant were calculated as measures of early graft function.

RESULTS

Thirty-nine eligible patients (female n (%) 13 (33%)) with a median (IQR) age of 6 (3-9) years and pre-transplant eGFR of 7 (6-10) mL/min/1.73 m2 were analysed. Mean (SD) central venous pressure (CVP) after revascularisation was 11 (4) mmHg. Intraoperatively, mean volume of fluid administered was 84 (39) mL/kg, and 34 (87%) patients received vasoactive agents. Average systolic blood pressure (BP) in the first 24-h post-transplant was 117 (12) mmHg. Postoperatively, median volume of fluid administered in the first 24 h was 224 (159-313) mL/kg, and 17 (44%) patients received vasoactive agents. Median eGFR 7 days and 1-month post-transplant were 115 (79-148) and 103 (83-115) mL/min/1.73 m2, respectively. Linear regression analyses demonstrated that after adjusting for age, the average CVP after revascularisation and average systolic BP in the first 24-h post-transplant were not associated with eGFR in the first month post-transplant.

CONCLUSIONS

Targeted intraoperative and postoperative fluid and haemodynamic characteristics were achieved but did not correlate with early graft function.

Development and validation of a simple clinical nomogram for predicting infectious diseases in pediatric kidney transplantation recipients: a retrospective study

To construct and verify an easy-to-use nomogram for predicting the risk of infectious diseases in pediatric kidney transplant recipients. Clinical data of hospitalized pediatric kidney transplant recipients were retrospectively analyzed. Meaningful variables identified from the multivariate stepwise logistic regression analysis were used to construct the nomogram. Internal validation was performed using Bootstrap resampling 1,000 times. The nomogram was evaluated using calibration, decision and receiver operating characteristic (ROC) curves. A total of 297 pediatric kidney transplant recipients were included (164 infected, 133 non-infected). Multivariate stepwise regression analysis identified white blood cell count (WBC), lymphocyte to monocyte ratio (MLR), platelet to neutrophil ratio (PNR), red cell distribution width-standard deviation (RDW-SD), and albumin (ALB) as significant predictors of postoperative infection. The nomogram, based on the five indicators, showed strong discrimination ability (AUC = 0.756; 95% CI [0.702-0.811]), with a sensitivity of 88.0% and a specificity of 54.3%. The calibration curve and decision curve further demonstrated good consistency and clinical practicality between the predicted and actual values. WBC, MLR, PNR, RDW-SD, and ALB are effective indicators for predicting postoperative infection in pediatric kidney transplant recipients. The nomogram constructed from these indicators can effectively predict and evaluate the early risk of infection in these patients.

Pediatric Kidney Transplantation in an Under-resourced Country: A Single-Center Experience

OBJECTIVES

Kidney transplant is the optimal method for managing children with end-stage kidney disease. This study aimed to present the experience and results of the pediatric kidney transplant program at our center.

MATERIALS AND METHODS

A single-center observational study was conducted at Children's University Hospital in Damascus, Syria. We reviewed the medical records of all kidney transplants performed between April 2018 and December 2022. All patients were under 14 years old when they underwent kidney transplant. All donors were living, as an effective deceased donor program is currently not an option in Syria.

RESULTS

From April 2018 to December 2022, 33 pediatric kidney transplants were performed at our center. Most recipients were boys (n = 24; 72.7%), and 9 were girls (27.3%). Median age was 10 years (range, 4.5-14 y). The most frequent underlying diseases for kidney failure were renal dysplasia-hypoplasia (42.5%), reflux nephropathy (18.2%), and neurogenic bladder with posterior urethral valves (12%). In 10 patients, kidney transplant was performed preemptively (30.3%). Initial graft function was observed in all grafts (100%). During observation time (5 years), 28 patients (85%) retained adequate graft function. The 1-year graft and patient survival rates were 91%.

CONCLUSIONS

Syria is still suffering from the consequences of the war, affecting organ transplantation in many ways. The good 1-year graft and patient survival in our center was encouraging. However, we admit that the number of patients was small and the follow-up duration was also not long enough; future research is needed to improve long-term outcomes.

Family Environment, Social Support, and Health-Related Quality of Life in Adolescents Following Kidney Transplant

BACKGROUND

Kidney transplantation is the treatment of choice for pediatric end-stage renal disease. Transplant recipients often have better neurocognitive, academic, and health-related outcomes. While there is some evidence that health-related quality of life (HRQOL) improves following kidney transplant, other studies have found adolescent transplant recipients report lower overall HRQOL than healthy peers. Current research has focused on individual-level factors affecting adjustment to organ transplant, warranting examination of HRQOL from a systems perspective. Family environment and social support contribute to a system of proximal relationships that are crucial in adolescents' development, making them important factors to study in relation to HRQOL post-transplant.

METHODS

The current study utilized archival data of adolescent renal transplant patients who completed surveys about their family environment, social support, and HRQOL during routine transplant clinic visits.

RESULTS

Family cohesion, as well as social support from parents, classmates, and people in school, were positively correlated with HRQOL. Social support from people in school uniquely predicted variance in HRQOL, beyond the contribution of overall family environment after controlling for demographic factors. Relative to comparable adolescent samples, transplant recipients reported more optimal overall family environment, greater social support from teachers, and lower social support from close friends.

CONCLUSION

Psychosocial interventions for adolescent kidney transplant recipients may be enhanced by collaborating with school professionals and further bolstering strengths in the family environment. Kidney transplant recipients may benefit from long-term intervention, as decreased HRQOL appears to persist years post-transplant.

Adrenal insufficiency in pediatric kidney transplantation recipients

BACKGROUND

Immunosuppression of pediatric kidney transplant (PKT) recipients often includes corticosteroids. Prolonged corticosteroid exposure has been associated with secondary adrenal insufficiency (AI); however, little is known about its impact on PKT recipients.

METHODS

This was a retrospective cohort review of PKT recipients to evaluate AI prevalence, risk factors, and adverse effects. AI risk was assessed using morning cortisol (MC) and diagnosis confirmed by an ACTH stimulation test. Potential risk factors and adverse effects were tested for associations with MC levels and AI diagnosis.

RESULTS

Fifty-one patients (60.8% male, age 7.4 (IQR 3.8, 13.1) years; 1 patient counted twice for repeat transplant) were included. Patients at risk for AI (MC < 240 nmol/L) underwent definitive ACTH stimulation testing, confirming AI in 13/51 (25.5%) patients. Identified risk factors for AI included current prednisone dosage (p = .001), 6-month prednisone exposure (p = .02), daily prednisone administration (p = .002), and rejection episodes since transplant (p = .001). MC level (2.5 years (IQR 1.1, 5.1) post-transplant) was associated with current prednisone dosage (p < .001), 6-month prednisone exposure (p = .001), daily prednisone administration (p = .006), rejection episodes since transplant (p = .003), greater number of medications (β = -16.3, p < .001), 6-month hospitalization days (β = -3.3, p = .013), creatinine variability (β = -2.4, p = .025), and occurrence of acute kidney injury (β = -70.6, p = .01).

CONCLUSION

Greater corticosteroid exposure was associated with a lower MC level and confirmatory diagnosis of AI noted with an ACTH stimulation test. Adverse clinical findings with AI included greater medical complexity and kidney function lability. These data support systematic clinical surveillance for AI in PKT recipients treated with corticosteroids.

Evaluation of the implementation of a "Pediatric Feasibility Assessment for Transplantation" tool in children and adolescents at Red Cross War Memorial Children's Hospital, Cape Town, South Africa

BACKGROUND

Kidney transplantation remains the treatment of choice for children with kidney failure (KF). In South Africa, kidney replacement therapy (KRT) is restricted to children eligible for transplantation. This study reports on the implementation of the Paediatric Feasibility Assessment for Transplantation (pFAT) tool, a psychosocial risk score developed in South Africa to support transparent transplant eligibility assessment in a low-resource setting.

METHODS

Single-center retrospective descriptive analysis of children assessed for KRT using pFAT tool from 2015 to 2021.

RESULTS

Using the pFAT form, 88 children (median [range] age 12.0 [1.1 to 19.0] years) were assessed for KRT. Thirty (34.1%) children were not listed for KRT, scoring poorly in all domains, and were referred for supportive palliative care. Fourteen of these 30 children (46.7%) died, with a median survival of 6 months without dialysis. Nine children were reassessed and two were subsequently listed. Residing >300 km from the hospital (p = .009) and having adherence concerns (p = .003) were independently associated with nonlisting. Of the 58 (65.9%) children listed for KRT, 40 (69.0%) were transplanted. One-year patient and graft survival were 97.2% and 88.6%, respectively. Only one of the four grafts lost at 1-year posttransplant was attributed to psychosocial issues.

CONCLUSIONS

Short-term outcomes among children listed using the pFAT form are good. Among those nonlisted, the pFAT highlights specific psychosocial/socioeconomic barriers, over which most children themselves have no power to change, which should be systemically addressed to permit eligibility of more children and save lives.

IL-13 alleviates acute kidney injury and promotes regeneration via activating the JAK-STAT signaling pathway in a rat kidney transplantation model

AIMS

To identify whether and how a younger systemic internal milieu alleviates acute kidney injury (AKI) in grafts after kidney transplantation.

MATERIALS AND METHODS

We conducted an allogenic heterotopic rat kidney transplantation model with young and adult recipients receiving similar donor kidneys. We evaluated the renal function, histological damage, apoptosis, dedifferentiation, proliferation, hub regulating cytokines, and signaling pathways involved in young and adult recipients based on transcriptomics, proteomics, and experimental validation. We also validated the protective effect and mechanism of interleukin-13 (IL-13) on tubular epithelial cell injury induced by transplantation in vivo and by cisplatin in vitro.

KEY FINDINGS

Compared with adult recipients, the young recipients had lower levels of renal histological damage and apoptosis, while had higher levels of dedifferentiation and proliferation. Serum IL-13 levels were higher in young recipients both before and after surgery. Pretreating with IL-13 decreased apoptosis and promoted regeneration in injured rat tubular epithelial cells induced by cisplatin, while this effect can be counteracted by a JAK2 and STAT3 specific inhibitor, AG490. Recipients pretreated with IL-13 also had lower levels of histological damage and improved renal function.

SIGNIFICANCE

Higher levels of IL-13 in young recipients ameliorates tubular epithelial cell apoptosis and promotes regeneration via activating the JAK-STAT signaling pathway both in vivo and in vitro. Our results suggest that IL-13 is a promising therapeutic strategy for alleviating AKI. The therapeutic potential of IL-13 in injury repair and immune regulation deserves further evaluation and clinical consideration.

Venous vascular reconstruction of a robotically procured right kidney with two renal veins transplanted into a pediatric recipient

BACKGROUND

Right versus left kidney donor nephrectomy remains a controversial topic in renal transplantation given the increased incidence of right kidney vascular anomalies and associated venous thrombosis. We present the case of a 3-year-old pediatric recipient with urethral atresia and end-stage kidney disease who received a robotically procured living donor right pelvic kidney with two short same-size renal veins and a short ureter.

METHODS

We utilized a completely deceased iliac vein system (common iliac vein with both external and internal veins) to extend the two renal veins. Due to the distance between both renal veins, the external iliac vein was anastomosed to the upper hilum renal vein, and the internal iliac vein was anastomosed to the lower hilum renal vein. The donor's short ureter was anastomosed to the recipient's ureter end-to-side.

RESULTS

The patient had immediate graft function and there were no post-operative complications. Renal ultrasound was unremarkable at 48 hours post-transplant. Serum creatinine was 0.5 mg/dL at 3 months post-transplant.

CONCLUSION

We demonstrate the successful transplantation of a robotically procured right pelvic donor kidney with two short renal veins using a deceased donor iliac vein system for venous reconstruction without increasing technical complications. This technique of venous reconstruction can be used in right kidneys with similar anatomical variations without affecting graft function.

Understanding the impact of pediatric kidney transplantation on cognition: A review of the literature

BACKGROUND

Chronic kidney disease (CKD) is a relatively rare childhood disease that is associated with a wide array of medical comorbidities. Roughly half of all pediatric patients acquire CKD due to congenital anomalies of the kidneys and urinary tract, and of those with congenital disease, 50% will progress to end-stage kidney disease (ESKD) necessitating a kidney transplantation. The medical sequelae of advanced CKD/ESKD improve dramatically following successful kidney transplantation; however, the impact of kidney transplantation on neurocognition in children is less clear. It is generally thought that cognition improves following kidney transplantation; however, our knowledge on this topic is limited by the sparsity of high-quality data in the context of the relative rarity of pediatric CKD/ESKD.

METHOD

We conducted a narrative review to gauge the scope of the literature, using the PubMed database and the following keywords: cognition, kidney, brain, pediatric, neurocognition, intelligence, executive function, transplant, immunosuppression, and neuroimaging.

RESULTS

There are few published longitudinal studies, and existing work often includes wide heterogeneity in age at transplant, variable dialysis exposure/duration prior to transplant, and unaccounted cofounders which persist following transplantation, including socio-economic status. Furthermore, the impact of long-term maintenance immunosuppression on the brain and cognitive function of pediatric kidney transplant (KT) recipients remains unknown.

CONCLUSION

In this educational review, we highlight what is known on the topic of neurocognition and neuroimaging in the pediatric KT population.

Kidney transplant access for children and young adults with congenital anomalies of the kidney and urinary tract

PURPOSE

Although congenital anomalies of the kidney and urinary tract (CAKUT) are among the leading causes of end-stage kidney disease (ESKD) in children and young adults, kidney transplantation access for this population has not been well studied in the US. We compared transplantation access in the US based on whether the etiology of kidney disease was secondary to CAKUT, and additionally by CAKUT subgroups (anatomic vs. inherited causes of CAKUT).

METHODS

Using the United States Renal Data System, we conducted a retrospective cohort study of 80,531 children and young adults who started dialysis between 1995 and 2015. We used adjusted Cox models to examine the association between etiology of kidney disease (CAKUT vs. non-CAKUT, anatomic vs. inherited) and receipt of kidney transplantation, and secondarily, receipt of a living vs. deceased donor kidney transplant.

RESULTS

Overall, we found an increased likelihood of kidney transplantation access for participants with CAKUT compared to those without CAKUT (HR 1.23; 95% CI 1.20-1.27). Among the subset of individuals with CAKUT as the attributed cause of ESKD, we found a lower likelihood of kidney transplantation in those with anatomic causes of CAKUT compared to those with inherited causes of CAKUT (adjusted HR 0.85; 0.81-0.90).

CONCLUSION

There are notable disparities in kidney transplantation rates among CAKUT subgroups. Those with anatomic causes of CAKUT started on dialysis have significantly reduced access to kidney transplantations compared to individuals with inherited causes of CAKUT who were initiated on dialysis. Further studies are needed to understand barriers to transplantation access in this population.

Preliminary Evaluation of Sedentary Lifestyle in Italian Children after Solid Transplant: What Role Could Physical Activity Play in Health? It Is Time to Move

BACKGROUND

Advances in the medical-surgical field have significantly increased survival after solid organ transplantation in the pediatric population. However, these patients are predisposed to the development of long-term complications (e.g., cardiovascular disease). The therapeutic role of physical activity (PA) to counteract these complications is well known. The purpose of the study was to investigate the level of PA in a pediatric population after solid organ transplantation.

METHODS

In the first 4 weeks at the beginning of the school year, the Physical Activity Questionnaire for Older Children and Adolescents was administered to young patients who had previously undergone solid transplants at our institute.

RESULTS

Questionnaires of 49 patients (57.1% female, mean age 13.2 ± 3.5 years) were analyzed and 32.7% of subjects did not perform any exercise during school physical education classes. Only 24% practiced a moderate quantity of exercise in the previous week (2-3 times/week) and 72% engaged in sedentary behaviors during weekends.

CONCLUSIONS

Preliminary data confirmed that young recipients are still far from meeting the minimum indications of the World Health Organization on PA and sedentary behavior. It will be necessary to increase their involvement in PA programs in order not only to increase their life expectancy but also to improve their quality of life.

Paediatric kidney transplantation: Towards a framework for pretransplant urological evaluation

The role of the urologist in paediatric kidney transplantation has evolved alongside advances in management for the various causes of end-stage kidney disease. Improvements in antenatal intervention and postnatal care have seen children with increasingly complex urological anomalies survive until transplant. Once solely responsible for the oversight of a child's surgical care, the paediatric urologist now works within a multidisciplinary transplant team, alongside transplant surgeons, paediatric nephrologists, transplant coordinators, psychologists, social workers, and transitional care specialists. We sought to identify available pretransplant evaluation frameworks to guide urological preparation and decision-making. Drawing from available evidence and reflecting on multi-institutional experience, we propose a streamlined approach to urologic assessment, which recognises that optimal transplant outcomes in this heterogenous cohort require lower urinary tract dysfunction to be carefully defined preoperatively.

Pharmaceutical services based on therapeutic care pathway for kidney transplantation from donors of infants and young children: a single-center experience

BACKGROUND

The pharmaceutical services based on therapeutic care pathway for kidney transplantation from infants and young children (age <3 years, weight <15 kg) to pediatric recipients can detect and resolve medication-related problems. In this paper, we report our experience on pharmaceutical services based on therapeutic care pathway to evaluate the therapeutic effects and assess the feasibility of perioperative treatment protocols.

METHODS

We performed a retrospective study of 12 recipients who received their graft from infants and young children, between September 2011 and December 2013 at our institution. As providers of pharmaceutical services, the clinical pharmacists collected and reviewed the clinical data from all patients, including the clinical characteristics, outcome indices, and follow-up dates. A three-step-protocol of pharmaceutical services including clinician's application, pharmacist consultation, and ongoing direct pharmaceutical care and follow-up was used through the entire length of patient's admission, hospitalization, and discharge. This protocol was developed and refined based on the guidelines for transplant perioperative treatment and experiences of the clinical pharmacists to standardize the workflow, and improve the medical treatment and quality of life of patients.

RESULTS

There was no acute rejection, graft loss, or death in 10 recipients after transplantation, and another 2 received nephrectomy due to dysfunction. Postoperative follow-up of the patients who received the pharmaceutical services from the clinical pharmacist showed an effectiveness in managing medication-related complications, patient-related factors, and an improvement of the outcomes.

CONCLUSIONS

The three-step protocol of pharmaceutical services for pharmaceutical care and individual dosing regimen sponsored by pharmacists facilitated access to personalized therapies for children undergoing kidney transplantation in our hospital.

Impact of de novo donor-specific HLA antibodies on pediatric kidney transplant prognosis in patients with acute declined or stable allograft function

BACKGROUND

This retrospective multicenter long-term cohort study investigates de novo donor-specific HLA antibodies (dnDSA) impact on allograft survival in pediatric kidney transplantation (KTx), depending on allograft function at dnDSA detection.

METHODS

Seventy patients with dnDSA screening in the context of acute allograft dysfunction (AAD) (>50% serum creatinine increase) or routine follow-up were included during a 20-year period. Number of dnDSA specificities and HLA total mean fluorescence intensity (MFI-sum) were collected.

RESULTS

Median follow-up time was 8.6 years. Among the 22 dnDSA+ patients, 8 patients presented AAD. Compared with dnDSA- patients, allograft survival was shorter only in dnDSA+/AAD+ patients, regardless of dnDSA detection during the 5-year post-transplant period (9 patients) or later (13 patients) (log rank p < .001 and p < .001, respectively). One dnDSA+/AAD-, 7 dnDSA+/AAD+, and 5 dnDSA- patients lost their allograft. Allograft survival was shorter in dnDSA+/AAD+ patients compared with the 16 dnDSA-/AAD+ patients (log rank p < .001) but did not differ between dnDSA+/AAD- and dnDSA-/AAD- patients (log rank p = .157). dnDSA+/AAD+ and dnDSA-/AAD+ patients presented higher risk of allograft failure compared with the other patient groups after adjustment for recipient age at KTx, donor type, and incidence of delayed graft function (HR 11.322, 95% CI 3.094-41.429, p < .001). Concurrent MFI-sum >10 000 and multiple dnDSA specificities were more significantly associated with AAD, compared with each factor separately (p < .001).

CONCLUSIONS

In pediatric KTx, AAD shortens allograft survival in dnDSA+ patients, regardless of dnDSA time detection, and is commonly observed when high MFI-sum concurs with multiple dnDSA specificities. dnDSA without AAD incidence does not determinately affect allograft survival.

Trends in Survival for Pediatric Transplantation

OBJECTIVES

Progress in pediatric transplantation measured in the context of waitlist and posttransplant survival is well documented but falls short of providing a complete perspective for children and their families. An intent-to-treat analysis, in which we measure survival from listing to death regardless of whether a transplant is received, provides a more comprehensive perspective through which progress can be examined.

METHODS

Univariable and multivariable Cox regression was used to analyze factors impacting intent-to-treat survival in 12 984 children listed for heart transplant, 17 519 children listed for liver transplant, and 16 699 children listed for kidney transplant. The Kaplan-Meier method and log-rank test were used to assess change in waitlist, posttransplant, and intent-to-treat survival. Wait times and transplant rates were compared by using χ2 tests.

RESULTS

Intent-to-treat survival steadily improved from 1987 to 2017 in children listed for heart (hazard ratio [HR] 0.96, 95% confidence interval [CI] 0.96-0.97), liver (HR 0.95, 95% CI 0.94-0.97), and kidney (HR 0.97, 95% CI 0.95-0.99) transplant. Waitlist and posttransplant survival also improved steadily for all 3 organs. For heart transplant, the percentage of patients transplanted within 1 year significantly increased from 1987 to 2017 (60.8% vs 68.7%); however, no significant increase was observed in liver (68.9% vs 72.5%) or kidney (59.2% vs 62.7%) transplant.

CONCLUSIONS

Intent-to-treat survival, which is more representative of the patient perspective than individual metrics alone, steadily improved for heart, liver, and kidney transplant over the study period. Further efforts to maximize the donor pool, improve posttransplant outcomes, and optimize patient care while on the waitlist may contribute to future progress.

Pediatric hemodialysis access

Pediatric hemodialysis access is a demanding field. Procedures are infrequent, technically challenging, and associated with high complication and failure rates. Each procedure affects subsequent access and transplants sites. The choice is made easier and outcomes improved when access decisions are made by a multidisciplinary, pediatric, hemodialysis access team. This manuscript reviews the current literature and offers technical suggestions to improve outcomes.

Contrast-enhanced ultrasound of transplant organs - liver and kidney - in children

Ultrasound (US) is the first-line imaging tool for evaluating liver and kidney transplants during and after the surgical procedures. In most patients after organ transplantation, gray-scale US coupled with color/power and spectral Doppler techniques is used to evaluate the transplant organs, assess the patency of vascular structures, and identify potential complications. In technically difficult or inconclusive cases, however, contrast-enhanced ultrasound (CEUS) can provide prompt and accurate diagnostic information that is essential for management decisions. CEUS is indicated to evaluate for vascular complications including vascular stenosis or thrombosis, active bleeding, pseudoaneurysms and arteriovenous fistulas. Parenchymal indications for CEUS include evaluation for perfusion defects and focal inflammatory and non-inflammatory lesions. When transplant rejection is suspected, CEUS can assist with prompt intervention by excluding potential underlying causes for organ dysfunction. Intracavitary CEUS applications can evaluate the biliary tract of a liver transplant (e.g., for biliary strictures, bile leak or intraductal stones) or the urinary tract of a renal transplant (e.g., for urinary obstruction, urine leak or vesicoureteral reflux) as well as the position and patency of hepatic, biliary and renal drains and catheters. The aim of this review is to present current experience regarding the use of CEUS to evaluate liver and renal transplants, focusing on the examination technique and interpretation of the main imaging findings, predominantly those related to vascular complications.

Surgical complications in pediatric kidney transplantation-Incidence, risk factors, and effects on graft survival: A retrospective single-center study

The field of pediatric kidney transplantation remains challenging due to an ongoing lack of size-matched grafts and anatomical peculiarities. In the current study, we investigated the incidence of surgical complications in pediatric recipients, with a focus on risk factors and effects on graft outcome. We retrospectively reviewed all 2386 kidney transplantations at our institution from January 2005 until December 2018. Of these, 221 transplants were performed in pediatric recipients, defined as under the age of 18 years. Donor-recipient body surface area ratios were calculated to evaluate the effects of size mismatching. Regression analyses were performed to identify independent risk factors for surgical complications and graft survival, respectively. Perioperative surgical complications requiring revision were observed in 34 (15.4%) cases. Leading cause for revision were vascular complications such as thrombosis or stenosis (n = 15 [6.8%]), which were significantly more frequent in case of young donors, (ie, donor age <6 years; OR: 4.281; CI-95%:1.385-13.226; P = .012), previous nephrectomy (OR: 3.407; CI-95%:1.019-11.387; P = .046), and en-bloc grafts (OR: 4.923; CI-95%:1.355-17.884; P = .015), followed by postoperative hemorrhage (n = 10 [4.5%]), ureteral complications (n = 8 [3.6%]), and lymphoceles (n = 7 [3.2%]). Median follow-up was 84.13 (0.92-175.72) months. One-, 5-, and 10-year graft survival rates were 97.1%, 88.9%, and 65.1%, respectively. Except for vascular complications (HR: 4.727; CI-95%:1.363-16.394; P = .014), none of the analyzed surgical morbidities significantly influenced graft survival. In conclusion, pediatric kidney transplantation achieves excellent long-term results. However, meticulous surgical technique and continuous postoperative monitoring are imperative for early detection and treatment of imminent vascular complications, especially in case of young donors and en-bloc grafts.

Donor-derived cell-free DNA (dd-cfDNA) for detection of allograft rejection in pediatric kidney transplants

In pediatric transplantation, acute rejection is a major contributor of graft failure. Current approaches include kidney biopsy in response to graft dysfunction and/or the emergence of donor-specific HLA antibodies (DSA). However, biopsy is associated with potential complications. Thus, there is a need for non-invasive diagnostics. Detection of donor-derived cell-free DNA (dd-cfDNA, AlloSure) > 1% is associated with rejection in adult kidney transplants. Here, we evaluate the utility of dd-cfDNA for identifying allograft rejection in pediatric patients. Between 10/2017 and 10/2019, 67 patients, who underwent initial testing with dd-cfDNA as part of routine monitoring or in response to clinical suspicion for rejection, were included. Biopsies were performed when dd-cfDNA > 1.0% or where clinical suspicion was high. Demographics, dd-cfDNA, antibody status, and biopsies were collected prospectively. Data were analyzed to determine predictive value of dd-cfDNA for identifying grafts at risk for rejection. 19 of 67 patients had dd-cfDNA testing as part of routine monitoring with a median dd-cfDNA score of 0.37 (IQR: 0.19-1.10). 48 of 67 patients who had clinical suspicion of rejection had median dd-cfDNA score of 0.47 (0.24-2.15). DSA-positive recipients had higher dd-cfDNA scores than those who were negative or had AT1R positivity alone (P = .003). There was no association between dd-cfDNA score and strength of DSA positivity. 7 of 48 recipients had a biopsy with a dd-cfDNA score <1%; two showed evidence of rejection. Neither DSA nor AT1R positivity was statistically associated with biopsy-proven rejection. However, dd-cfDNA >1% was diagnostic of rejection with sensitivity of 86% and specificity of 100% (AUC: 0.996, 0.98-1.00; P = .002). dd-cfDNA represents a non-invasive method for early detection of rejection in pediatric renal transplants. Our study shows dd-cfDNA to be highly predictive of histological rejection and superior to other indicators such as graft dysfunction or antibody positivity alone. Further studies are necessary to refine these initial observations.

Considerations and controversies of pharmacologic management of the pediatric kidney transplant recipient

Pediatric kidney transplantation has experienced considerable growth and improvement in patient and allograft outcomes over the past 20 years, in part due to advancements in immunosuppressive regimens and management. Despite this progress, care for this unique population can be challenging due to limited pediatric transplant data and trials, intricacies related to differences in children and adolescents compared with their adult counterparts, and limitations to long-term survival facing all solid organ transplant populations. Immunosuppression and infection prevention practices vary from one pediatric transplant center to another and clinical controversies exist surrounding treatment and dosing. This review aims to summarize key aspects of pharmacologic management in this population and present pertinent data that describe the influence of practice to serve as a resource for practitioners caring for this unique specialty patient population. Additionally, this review highlights select controversies that exist within pediatric kidney transplantation.

En Bloc Kidney Transplant From a Pediatric Donor to a Pediatric Recipient Through a Total Extraperitoneal Approach: A Case Report

En bloc kidney transplant remains a technically challenging procedure, especially in pediatric transplants. The intra-abdominal approach has been the preferred operation for very young children. However, the transverse incision could result in more abdominal muscle damage and intra-abdominal adhesions. If the extraperitoneal approach, which is the standard method for adult kidney transplant, could be performed in pediatric recipients, then adverse effects after a transverse incision could be avoided. A 30-month-old female recipient (13.1 kg) underwent an en bloc kidney transplant from a 36-month-old female donor (13.3 kg) who had cardiac arrest of unknown origin. The kidneys were retrieved with the en bloc technique using a bladder patch. A right Gibson incision was made along the lateral fascia of the rectus muscle of the recipient to prevent muscle fiber damage. The inferior vena cava and aorta of the donor were anastomosed to the inferior vena cava and right common iliac artery of the recipient, respectively. The bladder patch with 2 ureteral openings was directly anastomosed to the bladder of the recipient. Urination was excellent immediately after the operation. The recipient recovered quickly. The total extraperitoneal approach is feasible and has some advantages over the transverse incision, even in pediatric recipients.

Characterizing the frequency of modifiable histological changes observed on surveillance biopsies in pediatric kidney allograft recipients

BACKGROUND

Rejection is responsible for just under 50% of graft loss in the pediatric kidney transplant population. Early identification and treatment of allograft injury, specifically modifiable pathologies such as subclinical rejection (SCR), calcineurin inhibitor toxicity, and BK virus nephropathy, may improve allograft survival. Protocol surveillance biopsy (SB) currently offers the earliest opportunity for targeted interventions.

METHODS

This is a single-center retrospective review of 215 kidney SBs obtained from 2008 to 2016 in 97 pediatric kidney transplant recipients. SBs were obtained at 6, 12, and 24 months post-transplantation. Frequency of abnormal histologic findings, estimated glomerular filtration rate at time of SB, and SB-related complications were recorded. Data were analyzed to investigate possible time trends and the presence of demographic or clinical associations with abnormal histologic findings.

RESULTS

Potentially modifiable histologic findings were seen in 38.1% of all SBs. SCR was found with increasing frequency across all time points with an estimated 49% increase in the odds of a SCR finding per additional 6 months post-transplantation (aOR 1.49, 95% CI 1.06-2.09, p = 0.022). Among follow-up biopsies in patients who underwent treatment for SCR, 50% had no SCR and 18.8% showed histologic improvement. The complication rate associated with SB was 1.9% (4/215 SBs) and consisted of only minor complications.

CONCLUSIONS

SBs are safe and offer the opportunity to identify and treat modifiable histologic changes in the pediatric kidney transplant population. The performance of SBs for up to 2 years after transplantation can have meaningful clinical impact.

Kidney transplantation with allografts from infant donors-Small organs, big value

BACKGROUND

Although infant organ donors remain a rare source of organs for transplantation, technical challenges have resulted in increased rates of complications and inferior graft function. The aim of the present study was to investigate the outcomes of kidneys procured from juvenile and infant donors.

PATIENTS AND METHODS

We evaluated all kidney transplants from deceased donors < 16 years of age performed at our center between 01/2008 and 08/2019. We defined three groups based on quartiles of donor body weight: <13 kg (infant donors), 13-40 kg (juvenile donors), and > 40 kg (standard criteria donors). Clinical characteristics and outcomes were compared between groups.

RESULTS

Ninety-two transplants were included in this study. Out of 92 recipients, there were 32 (34.8%) adult and 60 (65.2%) pediatric patients. All groups demonstrated excellent graft function and survival on both short and long-term follow-up. 1-year, 3-year, and 5-year graft survival rates for the standard criteria donor group were 100%, 95.2%, and 88.4%, respectively, compared with 95.8% for infant and 95% for juvenile donors at all times (P = .79). eGFR at 5 years was 98.9 ± 5.5, 74.1 ± 6.2, and 81.6 ± 6.9 mL/min/1.73 m² for infant, juvenile, and standard criteria donors, respectively (P < .01).

CONCLUSION

Infant donor allografts can be transplanted with excellent long-term outcomes in both pediatric and adult recipients. Implanting them as single allografts onto pediatric candidates allows for the transplantation of two patients. As such, pediatric recipients should be prioritized for these donor organs.

Access to Transplantation for Undocumented Pediatric Patients

Clinicians in the United States today regularly face dilemmas about health disparities. Many patients and families cannot afford the medical care that doctors recommend. These problems are most stark when the medical care that is needed is lifesaving and expensive and involves scarce resources. Transplants are the best example of this. The most ethically disturbing situations occur when an undocumented immigrant child needs a transplant. We present such a case and analyze the ethical, legal, and policy issues that arise.

Risk Assessment of Severe Congenital Anomalies of the Kidney and Urinary Tract (CAKUT): A Birth Cohort

Recent advances in the early diagnosis of fetal CAKUT with an increase in fetal surgical interventions have led to a growing number of neonatal survivors born with severe renal dysfunction. This, in turn, has required the development of multi-disciplinary treatment paradigms in the individualized management of these infants with advanced stage kidney disease from birth. Early multi-modal management includes neonatal surgical interventions directed toward establishing adequate urine flow, respiratory support with the assessment of pulmonary hypoplasia, and establishing metabolic control to avoid the need for dialysis intervention. The development of specialized imaging to assess for residual renal mass with non-invasive 3-dimensional techniques are rapidly evolving. The use of non-radioactive imaging offers improved safety and allows for early prognostic-based planning including anticipatory guidance for progression to end stage renal disease (ESRD). The trajectory of kidney function during the neonatal period as determined by peak and nadir serum creatinine (SCr) and cystatin C (CysC) during the first months of life provides a guide toward individualized prospective management. This is a single center experience based on a birth cohort of 42 subjects followed prospectively from birth for an average of 6.1 ± 2.8 years at the University of Miami/Holtz Children's Hospital during the past decade. There was an 8:1 male: female ratio. The birth cohort was divided into 3 subgroups according to CKD Stages at the current age: CKD 1-2 (Group 1) (eGFR ≥ 60 ml/min/1.73 m2) (N = 15), CKD stage 3-5 (Group 2) (eGFR ≤ 59 ml/min/1.73 m2) (N = 12), and ESRD-Dialysis and/or Transplantation (Group 3) (N = 15). A neonatal CysC >3.0 mg/L predicted progression to ESRD while a nadir SCr >0.6 mg/dL predicted progression to CKD 3-5 with the highest specificity and sensitivity by ROC-AUC analysis (P < 0.0001). Medical management was directed toward nutritional support with novel formula designs, early introduction of growth hormone and strict control of mineral bone disorder. One of the central aspects of the management was to avoid dialysis for as long as feasible with a primary goal toward pre-emptive transplantation.