Torque Teno Virus Loads as a Marker of Immunosuppression in Pediatric Kidney Transplant Recipients.

BACKGROUND: Long-term renal function and survival after kidney transplantation rely on appropriate immunosuppressive treatment to prevent the risk of rejection. New biomarkers are needed to accurately assess the degree of immunosuppression in renal transplant recipients in order to avoid organ rejection and the development of opportunistic infections. Highly prevalent in humans, torque teno virus (TTV), which belongs to the family Anelloviridae, is a small, nonenveloped, single-stranded DNA virus which has not been linked with any specific human illness, but which constitutes a major component of the human virome. Host antiviral responses allow TTV levels to be controlled; however, viral persistence remains, explaining the high prevalence in human populations, including healthy individuals. Important confounders of TTV load include time since transplantation, age, gender, obesity, and smoking status. AIMS: TTV-based guidance of immunosuppressive drug dosing could help with risk stratification, reducing the risk of infection, graft rejection and oncologic disease on an individual level, enabling long-term patient and graft survival. METHODS: Original studies were accessed by a systematic search from electronic databases including PubMed, ScienceDirect and Wiley Online Library. RESULTS: The presented data mainly derive from adult transplant recipients showing an association between TTV plasma levels and the immune status of the host: High-TTV load and high immunosuppression are associated with a risk of infection, and low-TTV load and low immunosuppression indicate a risk of rejection. However, there is minimal information on pediatric transplant recipients with further research required in this cohort. To date, it has been demonstrated that longer posttransplant times are significantly associated with lower TTV levels in children with renal transplant. Meanwhile, an association between lower TTV loads and increased risk of graft reject during the first year of transplantation was also reported. More recently, Eibensteiner et al. revealed a robust, independent association between TTV plasma load and the onset of Cytomegalovirus and BK virus infections. CONCLUSION: Data from randomized controlled trials are still missing, even in adults, but a multicenter randomized controlled trial for TTV-guided immunosuppression in adult kidney recipients (TTVguideIT) began in 2022. There is, therefore, great promise for TTV levels to be used as a biomarker that could potentially improve both graft and patient survival in transplantation.

An unusual case of nephrotic syndrome.

BACKGROUND: Alport syndrome is a genetically heterogenous disorder resulting from variants in genes coding for alpha-3/4/5 chains of Collagen IV, which results in defective basement membranes in the kidney, cochlea and eye. The syndrome has different inheritance patterns and historically, was thought of as a disease affecting solely males. CASE: A 15-year-old female presented with pedal oedema, hypertension and proteinuria. She underwent a kidney biopsy which showed findings in keeping with focal segmental glomerulosclerosis. Her condition was refractory to steroids. Steroid-resistant nephrotic syndrome genetics were sent, revealing a rare pathogenic variant in the COL4A5 gene. CONCLUSION: Heterozygous females with X-linked Alport syndrome can develop chronic kidney disease and hearing loss. Clinicians should be mindful when reviewing kidney histology to include Alport syndrome as a differential for female patients. COL4A3-5 genes should be included in all steroid-resistant nephrotic syndrome genetic panels.

Transitional care models in adolescent kidney transplant recipients-a systematic review.

BACKGROUND: Adolescence is a time of significant change for patients, guardians and clinicians. The paediatrician must ensure patients develop the necessary skills and knowledge required to transition and to function as an independent entity, with autonomy over their own care. The transfer from paediatric to adult care carries an increased risk of graft-related complications attributable to a multitude of reasons, particularly non-adherence to immunosuppressive medicines and poor attendance at scheduled appointments. This systematic review was conducted to ascertain the transitional care models available to clinicians caring for kidney transplant recipients and to compare the approach in each respective case. METHODS: A systematic review was performed, in a methodology outlined by the PRISMA guidelines. OVID MEDLINE and EMBASE databases were searched for studies that outlined valid, replicable models pertaining to transitional care of paediatric kidney transplant recipients between 1946 and Quarter 3 of 2021. The reference lists of selected articles were also perused for further eligible studies and experts in the field were consulted for further eligible articles. Two investigators assessed all studies for eligibility and independently performed data extraction. Any discrepancies were settled by consensus. RESULTS: A total of 1121 abstracts were identified, which was reduced to 1029 upon removal of duplicates. A total of 51 articles were deemed appropriate for full-text review and critical appraisal. A total of 12 articles that described models for transition pertaining to kidney transplant patients were included in qualitative synthesis. Every paper utilized a different transition model. All but one model included a physician and nurse at minimum in the transition process. The involvement of adult nephrologists, medical social work, psychology and psychiatry was variable. The mean age for the initiation of transition was 13.4 years (range: 10-17.5 years). The mean age at transfer to adult services was 18.3 years (range: 16-20.5 years). CONCLUSIONS: Despite the well-established need for good transitional care for paediatric solid-organ transplant recipients, models tailored specifically for kidney transplant recipients are lacking. Further research and validation studies are required to ascertain the best method of providing effective transitional care to these patients. Transitional care should become a standardized process for adolescents and young adults with kidney transplants.

Neurological involvement in children with hemolytic uremic syndrome.

Our objective was to establish the rate of neurological involvement in Shiga toxin-producing Escherichia coli-hemolytic uremic syndrome (STEC-HUS) and describe the clinical presentation, management and outcome. A retrospective chart review of children aged ≤ 16 years with STEC-HUS in Children's Health Ireland from 2005 to 2018 was conducted. Laboratory confirmation of STEC infection was required for inclusion. Neurological involvement was defined as encephalopathy, focal neurological deficit, and/or seizure activity. Data on clinical presentation, management, and outcome were collected. We identified 240 children with HUS; 202 had confirmed STEC infection. Neurological involvement occurred in 22 (11%). The most common presentation was seizures (73%). In the neurological group, 19 (86%) were treated with plasma exchange and/or eculizumab. Of the 21 surviving children with neurological involvement, 19 (91%) achieved a complete neurological recovery. A higher proportion of children in the neurological group had renal sequelae (27% vs. 12%, P = .031). One patient died from multi-organ failure.Conclusion: We have identified the rate of neurological involvement in a large cohort of children with STEC-HUS as 11%. Neurological involvement in STEC-HUS is associated with good long-term outcome (complete neurological recovery in 91%) and a low case-fatality rate (4.5%) in our cohort. What is Known: • HUS is associated with neurological involvement in up to 30% of cases. • Neurological involvement has been reported as predictor of poor outcome, with associated increased morbidity and mortality. What is New: • The incidence of neurological involvement in STEC-HUS is 11%. • Neurological involvement is associated with predominantly good long-term outcome (90%) and a reduced case-fatality rate (4.5%) compared to older reports.

Long-term outcome of transplant ureterostomy in children: A National Review.

BACKGROUND: CAKUT are the most common cause of end-stage renal failure in children (Pediatr Nephrol. 24, 2009, 1719). Many children with CAKUT have poor urinary drainage which can compromise post-transplant outcome. Identifying safe ways to manage anatomical abnormalities and provide effective urinary drainage is key to transplant success. Much debate exists regarding optimum urinary diversion techniques. The definitive formation of a continent urinary diversion is always preferable but may not always be possible. We explore the role of ureterostomy formation at transplantation in a complex pediatric group. METHODS: We report six pediatric patients who had ureterostomy formation at the time of transplantation at the National Paediatric Transplant Centre in Dublin, Ireland. We compared renal function and burden of urinary tract infection to a group with alternative urinary diversion procedures and a group with normal bladders over a 5-year period. RESULTS: There was no demonstrable difference in estimated glomerular filtration rate between the groups at 5-year follow-up. The overall burden of UTI was low and similar in frequency between the three groups. CONCLUSIONS: Ureterostomy formation is a safe and effective option for temporary urinary diversion in children with complex abdominal anatomy facilitating transplantation; it is, however, important to consider the implications and risk of ureterostomy for definitive surgery after transplantation.

Clinical practice recommendations for recurrence of focal and segmental glomerulosclerosis/steroid-resistant nephrotic syndrome.

Recurrence of primary disease is one of the major risks for allograft loss after pediatric RTx. The risk of recurrence of FSGS/SRNS after pediatric RTx in particular can be up to 86% in idiopathic cases. There is a need for consensus recommendations on its prevention and treatment. The CERTAIN study group has therefore performed a thorough literature search based on the PICO model of clinical questions to formulate educated statements to guide the clinician in the process of decision-making. A set of educated statements on prevention and treatment of FSGS/SRNS after pediatric RTx has been generated after careful evaluation of available evidence and thorough panel discussion. We do not recommend routine nephrectomy prior to transplantation; neither do we recommend abstaining from living donation. Special attendance needs to be given to those patients who had already experienced graft loss due to FSGS/SRNS recurrence. Early PE or IA with or without high-dose CsA and/or rituximab seems to be most promising to induce remission. The educated statements presented here acknowledge that FSGS/SRNS recurrence after pediatric RTx remains a major concern and is associated with shorter graft survival or even graft loss. The value of any recommendation needs to take into account that evidence is based on cohorts that differ in ethnicity, pre-transplant history, immunosuppressive regimen, definition of recurrence (eg, clinical and/or histological diagnosis) and treatment modalities of recurrence.

Monogenic causes of chronic kidney disease in adults.

Approximately 500 monogenic causes of chronic kidney disease (CKD) have been identified, mainly in pediatric populations. The frequency of monogenic causes among adults with CKD has been less extensively studied. To determine the likelihood of detecting monogenic causes of CKD in adults presenting to nephrology services in Ireland, we conducted whole exome sequencing (WES) in a multi-centre cohort of 114 families including 138 affected individuals with CKD. Affected adults were recruited from 78 families with a positive family history, 16 families with extra-renal features, and 20 families with neither a family history nor extra-renal features. We detected a pathogenic mutation in a known CKD gene in 42 of 114 families (37%). A monogenic cause was identified in 36% of affected families with a positive family history of CKD, 69% of those with extra-renal features, and only 15% of those without a family history or extra-renal features. There was no difference in the rate of genetic diagnosis in individuals with childhood versus adult onset CKD. Among the 42 families in whom a monogenic cause was identified, WES confirmed the clinical diagnosis in 17 (40%), corrected the clinical diagnosis in 9 (22%), and established a diagnosis for the first time in 16 families referred with CKD of unknown etiology (38%). In this multi-centre study of adults with CKD, a molecular genetic diagnosis was established in over one-third of families. In the evolving era of precision medicine, WES may be an important tool to identify the cause of CKD in adults.

Management of bone disease in cystinosis: Statement from an international conference.

Cystinosis is an autosomal recessive storage disease due to impaired transport of cystine out of lysosomes. Since the accumulation of intracellular cystine affects all organs and tissues, the management of cystinosis requires a specialized multidisciplinary team consisting of pediatricians, nephrologists, nutritionists, ophthalmologists, endocrinologists, neurologists' geneticists, and orthopedic surgeons. Treatment with cysteamine can delay or prevent most clinical manifestations of cystinosis, except the renal Fanconi syndrome. Virtually all individuals with classical, nephropathic cystinosis suffer from cystinosis metabolic bone disease (CMBD), related to the renal Fanconi syndrome in infancy and progressive chronic kidney disease (CKD) later in life. Manifestations of CMBD include hypophosphatemic rickets in infancy, and renal osteodystrophy associated with CKD resulting in bone deformities, osteomalacia, osteoporosis, fractures, and short stature. Assessment of CMBD involves monitoring growth, leg deformities, blood levels of phosphate, electrolytes, bicarbonate, calcium, and alkaline phosphatase, periodically obtaining bone radiographs, determining levels of critical hormones and vitamins, such as thyroid hormone, parathyroid hormone, 25(OH) vitamin D, and testosterone in males, and surveillance for nonrenal complications of cystinosis such as myopathy. Treatment includes replacement of urinary losses, cystine depletion with oral cysteamine, vitamin D, hormone replacement, physical therapy, and corrective orthopedic surgery. The recommendations in this article came from an expert meeting on CMBD that took place in Salzburg, Austria, in December 2016.

Therapeutic plasma exchange in paediatric nephrology in Ireland.

BACKGROUND: Therapeutic plasma exchange (TPE) is utilised in the management of a limited number of paediatric renal conditions. Despite its widespread acceptance and advancements in the practice of apheresis, there remains a paucity of data pertaining to paediatrics. We present a large retrospective review of our cohort of paediatric patients undergoing TPE for renal indications, outlining their outcomes and complications. METHODS: A retrospective chart review was conducted for all patients (under 16 years) undergoing TPE for renal conditions between January 2002 and June 2019 in Ireland. Demographic and clinical data were extracted, with patients anonymised and stratified according to their pathology. RESULTS: A total of 58 patients were identified. A total of 1137 exchanges were performed using heparin sodium anticoagulation. The median age was 35.5 months (IQR 18-110 months). The leading indication was neurological involvement in Shiga toxin-producing Escherichia coli haemolytic uraemic syndrome (STEC-HUS) (n = 29). Complications (minor or major) occurred in 65.5% (n = 38) of patients, with most experiencing minor complications 58.6% (n = 34). Asymptomatic hypocalcaemia was the most common complication in 43.1% (n = 25). CONCLUSIONS: Our experience of TPE, spanning 1137 exchanges, proved a safe, well-tolerated therapy. Most complications were minor, and with therapy conducted in specialised centres, there are very low levels of adverse events.

Hyperparathyroidism Is an Independent Risk Factor for Allograft Dysfunction in Pediatric Kidney Transplantation.

Introduction: Little is known about the consequences of deranged chronic kidney disease-mineral and bone disorder (CKD-MBD) parameters on kidney allograft function in children. We examined a relationship between these parameters over time and allograft outcome. Methods: This registry study from the Cooperative European Paediatric Renal Transplant Initiative (CERTAIN) collected data at baseline, months 1, 3, 6, 9, and 12 after transplant; and every 6 months thereafter up to 5 years. Survival analysis for a composite end point of graft loss or estimated glomerular filtration rate (eGFR) ≤30 ml/min per 1.73 m2 or a ≥50% decline from eGFR at month 1 posttransplant was performed. Associations of parathyroid hormone (PTH), calcium, phosphate, and 25-hydroxyvitamin D (25(OH)D) with allograft outcome were investigated using conventional stratified Cox proportional hazards models and further verified with marginal structural models with time-varying covariates. Results: We report on 1210 patients (61% boys) from 16 European countries. The composite end point was reached in 250 grafts (21%), of which 11 (4%) were allograft losses. In the conventional Cox proportional hazards models adjusted for potential confounders, only hyperparathyroidism (hazard ratio [HR], 2.94; 95% confidence interval [CI], 1.82-4.74) and hyperphosphatemia (HR, 1.94; 95% CI, 1.28-2.92) were associated with the composite end point. Marginal structural models showed similar results for hyperparathyroidism (HR, 2.74; 95% CI, 1.71-4.38), whereas hyperphosphatemia was no longer significant (HR, 1.35; 95% CI, 0.87-2.09), suggesting that its association with graft dysfunction can be ascribed to a decline in eGFR. Conclusion: Hyperparathyroidism is a potential independent risk factor for allograft dysfunction in children.

Plasma EBV microRNAs in paediatric renal transplant recipients.

BACKGROUND: Epstein-Barr virus (EBV) was the first human virus identified to express microRNA (miRNA). To date, 44 mature miRNAs are encoded for within the EBV genome. EBV miRNAs have not been profiled in paediatric renal transplant recipients. In this study, we investigated circulating EBV miRNA profiles as novel biomarkers in paediatric renal transplant patients. METHODS: Forty-two microRNAs encoded within 2 EBV open reading frames (BART and BHRF) were examined in renal transplant recipients who resolved EBV infection (REI) or maintained chronic high viral loads (CHL), and in non-transplant patients with acute infectious mononucleosis (IM). RESULTS: Plasma EBV-miR-BART2-5p was present in higher numbers of IM (7/8) and CHL (7/10) compared to REI (7/12) patients. A trend was observed between the numbers of plasma EBV miRNAs expressed and EBV viral load (p < 0.07). Several EBV-miRs including BART7-3p, 15, 9-3p, 11-3p, 1-3p and 3-3p were detected in IM and CHL patients only. The lytic EBV-miRs, BHRF1-2-3p and 1-1, indicating active viral replication, were detected in IM patients only. One CHL patient developed post-transplant lymphoproliferative disease (PTLD) after several years and analysis of 10 samples over a 30-month period showed an average 24-fold higher change in plasma EBV-miR-BART2-5p compared to the CHL group and 110-fold higher change compared to the REI group. CONCLUSIONS: Our results suggest that EBV-miR-BART2-5p, which targets the stress-induced immune ligand MICB to escape recognition and elimination by NK cells, may have a role in sustaining high EBV viral loads in CHL paediatric kidney transplant recipients.

Outpatient pediatric renal transplant biopsy--is it safe?

The safe observation time following pediatric renal transplant biopsy is unknown. To predict the safety of day-care pediatric renal transplant biopsy, we retrospectively evaluated the timing, incidence and severity of post-biopsy complications in children observed overnight. Biopsies were performed under real time ultrasound guidance using an 18-gauge Bard Biopty needle. Coagulation screen and platelet counts were measured preprocedure. Hemoglobin (Hb) was measured preprocedure, at 6 h and at 1-day post-procedure. Twenty-eight of 45 children transplanted between January 2002 and May 2004 underwent 65 biopsies. There was gross hematuria following 8 (12%) biopsies; 2/8 occurred after 6 h. Hb fell by >15 g/L in six cases (9%) - three had Hb drop within 6 h post-procedure and three had a steady decline over 24 h. No patient required blood transfusion. Oral analgesia post-procedure was required in seven cases (11%). One of these had gross hematuria. No patient required surgical intervention or transfusion. Three complications were recorded >6 h post-biopsy but none required intervention. Daycare renal transplant biopsy appears to be safe in selected patients.