BK Polyomavirus in Pediatric Renal Transplantation-What We Know and What We Do Not.

BK polyomavirus (BKPyV) is still a real threat in the management of kidney transplantation. Immunosuppressive treatment disrupts the equilibrium between virus replication and immune response, and uncontrolled BKPyV replication leads to nephropathy (BKPyV nephropathy). The first evidence of BKPyV reactivation in transplant recipients is the detection of viral shedding in urine, which appears in 20% to 60% of patients, followed by BKPyV viremia in 10-20% of kidney transplant recipients. BKPyV nephropathy eventually occurs in 1-10% of this population, mainly within the first 2 years post-transplantation, causing graft loss in about half of those patients. Few data exist regarding the pediatric population and we focus on them. In this paper, we review the existing diagnostic methods and summarize the evidence on the role of BKPyV humoral and cellular immunity in modulating the clinical course of BKPyV infection and as potential predictors of the outcome. We look at the known risk factors for BKPyV nephropathy in the immunosuppressed patient. Finally, we propose a sensible clinical attitude in order to screen and manage BKPyV infection in kidney transplant children.

Case Report: Sustained Efficacy of Lumasiran at 18 Months in Primary Hyperoxaluria Type 1.

Background: Primary hyperoxaluria type 1 (PH1) is a rare genetic disease caused by hepatic overproduction of oxalate, ultimately responsible for kidney stones, kidney failure and systemic oxalosis. Lumasiran, is a liver-directed RNA interference therapeutic agent. It has been shown to reduce hepatic oxalate production by targeting glycolate oxidase, and to dramatically reduce oxalate excretion. Care Report: We present the case of a teenager patient affected by PH1, who entered in the lumasiran compassionate use program. The patient had a rapid and sustained decrease in urinary oxalate/creatinine ratio, with a mean reduction after lumasiran administration of about 70%. During the 18 months long follow-up, urinary oxalate remained low, reaching nearly normal values. Plasma oxalate also decreased dramatically. Normal levels were reached immediately after the first dose and remained consistently low thereafter. During the same follow-up period, eGFR remained stable at about 60 ml/min/1.73 m2, but no new kidney stones were observed. Existing kidney stones did not increase in size. The patient did not suffer renal colic events and did not require further urological interventions. Conclusion: In our severely affected PH1 patient, lumasiran proved to be very effective in rapidly and consistently reducing plasma oxalate and urinary excretion to normal and near-normal levels, respectively. In the 18 months long follow-up post-lumasiran, the eGFR remained stable and the patient showed clinical improvements. As far as we know, this report covers the longest observation period after initiation of this novel RNAi therapy.

Prospective Cohort Study Investigating the Safety and Efficacy of Ambulatory Treatment With Oral Cefuroxime-Axetil in Febrile Children With Urinary Tract Infection.

Aims: To assess the safety and efficacy of ambulatory oral cefuroxime-axetil treatment in children presenting with first febrile urinary tract infection (UTI) in terms of resolution of fever, antibiotics tolerance, bacterial resistance, and loss to ambulatory follow-up. Methods: Two-year prospective single-center evaluation of the local protocol of oral ambulatory treatment of children presenting first febrile urinary tract infection (UTI). Results: From October 2013 to October 2015, 82 children were treated ambulatory with oral cefuroxime-axetil. The median age was 8 months. When analyzing those 82 children treated orally, 51 (62%) completed oral treatment, 14 (17%) missed their scheduled follow-up visits (3 patients at day 2 and 11 patients at week 2), and 17 (21%) were switched to IV therapy for the following reasons: vomiting in 9, persistent fever in 5, antibiotic resistance in 2 and bacteremia in 1. Six children (8%) presented recurrent UTI after a median of 5 months of follow-up. Conclusions: This 2-year evaluation suggests that oral treatment with cefuroxime-axetil in febrile UTI is feasible but should be implemented with caution. Home-treated children require reevaluation during treatment since 21% of our cohort had to be temporarily switched to parenteral therapy and 17% did not attend scheduled follow-up visits during oral treatment.

Outcomes of kidney transplantations in children weighing 15 kilograms or less: a retrospective cohort study.

Kidney transplantation (KT) is often delayed in small children because of fear of postoperative complications. We report early- and long-term outcomes in children transplanted at ≤15 kg in the two largest Belgian pediatric transplant centers. Outcomes before (period 1) and since the introduction of basiliximab and mycophenolate-mofetil in 2000 (period 2) were compared. Seventy-two KTs were realized between 1978 and 2016: 38 in period 1 and 34 in period 2. Organs came from deceased donors in 48 (67%) cases. Surgical complications occurred in 25 KTs (35%) with no significant difference between the two periods. At least one acute rejection (AR) occurred in 24 (33%) KTs with significantly less patients experiencing AR during period 2: 53% and 12% in period 1 and, period 2 respectively (P < 0.001). Graft survival free of AR improved significantly in period 2 compared with period 1: 97% vs. 50% at 1 year; 87% vs. 50% at 10 years post-KT (P = 0.003). Graft survival tended to increase over time (period 1: 74% and 63% at 1 and 5 years; period 2: 94% and 86% at 1 and 5 years; P = 0.07), as well as patient survival. Kidney transplantation in children ≤15 kg remains a challenging procedure with 35% of surgical complications. However, outcomes improved and are nowadays excellent in terms of prevention of AR, patient and graft survival.

Early-onset of ADCK4 glomerulopathy with renal failure: a case report.

BACKGROUND: We present a rare early presentation of a ADCK4-related glomerulopathy. This case is of interest as potentially treatable if genetic results are timely obtained. CASE PRESENTATION: We report the case of a 5-year-old boy who was identified with significant proteinuria by a urinary routine screening program for school children. Physical examination revealed dysplastic ears and abnormal folded pinna. Albumin level was 41 g/L (39-53 g/L), and urine proteins/creatinine ratio was 2.6 g/g. Renal ultrasound showed enlarged kidneys and perimedullary hyperechogenicity. Treatment by angiotensin-converting-enzyme inhibitor was not beneficial. Renal biopsy showed signs of focal segmental glomerulosclerosis. After 4 years of follow-up, he developed a clinical nephrotic syndrome and no response to prednisone and other immunosuppressive agents was obtained. Within 6 months, he was in end-stage-renal-failure (ESRF) and hemodialysis was started. He was transplanted at 10 years with his mother's kidney. Genes known to be responsible in steroid-resistant nephrotic syndromes were tested. Our patient is compound heterozygous for two mutations in the aarF domain-containing-kinase 4 (ADCK4) gene. ADCK4 gene is one of the genes involved in coenzyme Q10 (CoQ10) biosynthesis, is located in chromosome 19q13.2 and expressed in podocytes. ADCK4 mutations show a largely renal-limited phenotype. The nephropathy usually presents during adolescence, fast evolves towards ESRF, and may be treatable by CoQ10 supplementation if started early in the disease. Our patient presented nephrotic range proteinuria at 5 years, and he reached ESRF at 10 years. CONCLUSION: ADCK4-related glomerulopathy is an important novel and potentially treatable cause of isolated nephropathy not only in adolescents, but also in children in their first decade of life. Discovery of important proteinuria in an asymptomatic child should prompt early genetic investigations.

Characteristics of first urinary tract infection with fever in children: a prospective clinical and imaging study.

BACKGROUND: Our objective is to provide the clinical characteristics, uropathogen frequencies, and antimicrobial resistance rates of first urinary tract infection (UTI) diagnosed in febrile Belgian children. The ability of noninvasive ultrasound to detect renal abnormalities and vesicoureteral reflux (VUR) in these patients was also assessed. METHODS: We prospectively followed (median, 20 months) 209 children treated for first febrile UTI. Renal ultrasound (US) and voiding cystourethrography examinations were performed in all patients. RESULTS: Among these children, 63% were females and 37% were males, and 75% of them had their first UTI before the age of 2 years. The most common causative agent was Escherichia coli (91% of cases) with high rate resistance to ampicillin (58%) and trimethoprim/sulfamethoxazole (38%). Of these children, 25% had evidence of VUR (15 boys and 38 girls). VUR was of low grade in 85% of cases. The overall performance of renal US as a diagnostic test to detect significant uropathies excluding low-grade VUR was excellent; the sensitivity attained 97% and the specificity 94%. CONCLUSION: Girls represent 63% of cases with first UTI. For 91% of UTIs, Escherichia coli is held responsible with a high rate of resistance to ampicillin and trimethoprim/sulfamethoxazole. US is an excellent screening tool that allows avoidance of unjustified voiding cystourethrography studies.

Febrile urinary tract infections in 0- to 3-month-old infants: a prospective follow-up study.

OBJECTIVE: To track the clinical evolution of febrile urinary tract infection (UTI) diagnosed in 0- to 3-month-old infants and characterize uropathogen frequencies, antimicrobial resistance rates, renal abnormalities, and differences in the sexes in this age group. STUDY DESIGN: We observed prospectively 46 infants identified in a cohort of 209 children with first UTI diagnosed between July 2006 and July 2008 at the age of 0 to 3 months. Renal ultrasound scanning and voiding cystourethrography examinations were performed in all infants. RESULTS: Infants < 3 months old represented 21% of all children with first UTI. Of these children, 26% were female and 74% were male. Escherichia coli was isolated in 88% of cases and had a high rate of resistance to ampicillin (71%) and to trimethoprim/sulfamethoxazole (47%); 21% of children had vesicoureteral reflux, which was of low-grade in 67% of cases, with spontaneous resolution before 2 years in all cases. In infants with normal ultrasound scanning results, a low-grade vesicoureteral reflux was subsequently found in 10% of cases. CONCLUSION: Infants aged 0 to 3 months represent 21% of children treated for febrile UTI. Boys represent 74% of these cases. E coli is responsible for 88% of UTIs, with a high rate of resistance to antibiotics. When ultrasound scanning examination results are normal, the risk of missing a significant renal abnormality is expected to be extremely low.