Hypertension in diabetes.

Diabetes mellitus, a disease that affects hundreds of millions of people worldwide, is increasing in prevalence in all age groups, including children and adolescents. Much of the morbidity and mortality associated with diabetes is closely related to hypertension, often coincident with diabetes. Comorbid hypertension and diabetes often worsen the outcomes of each other, likely rooted in some overlapping pathogenic mechanisms. In this educational review, we will discuss the shared pathophysiology of diabetes and hypertension, particularly in regard to inflammation and oxidative stress, the sympathetic nervous system, vascular remodeling, and the renin-angiotensin-aldosterone system (RAAS). We will also review current hypertension diagnosis and management guidelines from many international jurisdictions for both adult and paediatric populations in the setting of diabetes. Many of these guidelines highlight the use and utility of RAAS blockers in this clinical scenario; however, on review of the evidence for their use, several meta-analyses and systematic reviews fail to demonstrate superiority of RAAS blockers over other anti-hypertensive medications. Finally, we discuss several new anti-hypertensive medications, review their mechanisms of action, and highlight some of the evidence for their use in the setting of hypertension and diabetes.

Management dilemmas in pediatric nephrology: moving from friction to flourishing in "challenging" cases.

BACKGROUND: The circumstances surrounding chronic kidney disease and its impact on families can be complex and difficult to navigate, leading to these cases being labeled "challenging." CASE PRESENTATION: We present the case of an adolescent with kidney failure due to unremitting systemic illness and multiple complications ultimately resulting in the family's request to forgo dialysis. Medical team members wrestled with meeting the family's needs among internal and external constraints. CONCLUSION: Past experiences, systemic inequities, differing perspectives, and consequential decision-making within individual belief systems can lead to friction between and among medical team members and families. As pediatric nephrologists, we must shift our focus from the "challenging" patient or family to addressing what is challenging their ability to flourishing.

Impact of childhood nephrotic syndrome on obesity and growth: a prospective cohort study.

BACKGROUND: Children with nephrotic syndrome are at risk of obesity and growth impairment from repeated steroid treatment. However, incidence and risk factors for obesity and short stature remain uncertain, which is a barrier to preventative care. Our aim was to determine risk, timing, and predictors of obesity and short stature among children with nephrotic syndrome. METHODS: We evaluated obesity and longitudinal growth among children (1-18 years) enrolled in Insight into Nephrotic Syndrome: Investigating Genes, Health, and Therapeutics. We included children with nephrotic syndrome diagnosed between 1996-2019 from the Greater Toronto Area, Canada, excluding congenital or secondary nephrotic syndrome. Primary outcomes were obesity (body mass index Z-score ≥ + 2) and short stature (height Z-score ≤ -2). We evaluated prevalence of obesity and short stature at enrolment (< 1-year from diagnosis) and incidence during follow-up. Cox proportional hazards models determined the association between nephrotic syndrome classification and new-onset obesity and short stature. RESULTS: We included 531 children with nephrotic syndrome (30% frequently relapsing by 1-year). At enrolment, obesity prevalence was 23.5%, 51.8% were overweight, and 4.9% had short stature. Cumulative incidence of new-onset obesity and short stature over median 4.1-year follow-up was 17.7% and 3.3% respectively. Children with frequently relapsing or steroid dependent nephrotic syndrome within 1-year of diagnosis were at increased risk of new-onset short stature (unadjusted hazard ratio 3.99, 95%CI 1.26-12.62) but not obesity (adjusted hazard ratio 1.56, 95%CI 0.95-2.56). Children with ≥ 7 and ≥ 15 total relapses were more likely to develop obesity and short stature, respectively. CONCLUSIONS: Obesity is common among children with nephrotic syndrome early after diagnosis. Although short stature was uncommon overall, children with frequently relapsing or steroid dependent disease are at increased risk of developing short stature. Effective relapse prevention may reduce steroid toxicity and the risk of developing obesity or short stature.

Von Willebrand factor antigen as a marker of disease activity in childhood-onset antineutrophil cytoplasmic antibody-associated vasculitis.

OBJECTIVE: Von Willebrand Factor (VWF) antigen plays a role in vascular inflammation and thrombosis, both important in the pathogenesis of Antineutrophil Cytoplasmic Antibody-associated vasculitis (AAV). Previous work found that VWF correlates with disease activity in childhood-onset primary CNS vasculitis. We sought to determine the relationship between VWF and disease activity over time in children with AAV. METHODS: AAV patients with more than one VWF level measured were included in this retrospective stuy, and the relationship between active vasculitis, VWF and other disease measures were analyzed. Generalized estimating equations (GEE) analysis was used to account for repeated VWF measurements within a patient. Repeated measures correlation was used to determine associations of paired laboratory observations. Diagnostic performance was evaluated using receiver operating curve (ROC) analysis. RESULTS: 732 total VWF measurements were collected in 33 AAV patients. VWF antigen levels were higher during active disease (median = 2.03 IU/ml, IQR = [1.35, 2.55]) compared with inactive disease (median = 1.18 IU/ml, IQR = [0.94, 1.53). VWF antigen was the only variable that was significantly associated with active disease (OR 3.01, p< 0.001, 95CI [2.3, 3.93]). The effect of VWF did not show a substantial difference between the disease subtypes. There was a moderate positive correlation between VWF antigen and disease activity, with an acceptable sensitivity and specificity rates. CONCLUSION: Increased VWF antigen levels correlate with active vasculitis in this paediatric-onset AAV cohort and may be used as an additional biomarker in childhood AAV.

Therapeutic trials in difficult to treat steroid sensitive nephrotic syndrome: challenges and future directions.

Steroid sensitive nephrotic syndrome is a common condition in pediatric nephrology, and most children have excellent outcomes. Yet, 50% of children will require steroid-sparing agents due to frequently relapsing disease and may suffer consequences from steroid dependence or use of steroid-sparing agents. Several steroid-sparing therapeutic agents are available with few high quality randomized controlled trials to compare efficacy leading to reliance on observational data for clinical guidance. Reported trials focus on short-term outcomes such as time to first relapse, relapse rates up to 1-2 years of follow-up, and few have studied long-term remission. Trial designs often do not consider inter-individual variability, and differing response to treatments may occur due to heterogeneity in pathogenic mechanisms, and genetic and environmental influences. Strategies are proposed to improve the quantity and quality of trials in steroid sensitive nephrotic syndrome with integration of biomarkers, novel trial designs, and standardized outcomes, especially for long-term remission. Collaborative efforts among international trial networks will help move us toward a shared goal of finding a cure for children with nephrotic syndrome.

Utilizing therapeutic drug monitoring to optimize therapy with eculizumab and mycophenolate mofetil in a child with C3 glomerulonephritis.

BACKGROUND: C3 glomerulonephritis (C3GN) can be a devastating disease with poor response to immunosuppressive therapy. Complement inhibition with eculizumab has had equivocal results in patients with C3GN. CASE-DIAGNOSIS/TREATMENT: We report a case of a 6-year-old boy with C3GN presenting with nephrotic syndrome, severe hypertension and impaired kidney function. He did not respond to initial treatment with prednisone and mycophenolate (mofetil and sodium), and subsequent treatment with standard dosing of eculizumab. Pharmacokinetic studies identified a lack of eculizumab exposure and subsequent intensification of treatment with weekly dosing of eculizumab led to significant clinical improvement: his kidney function normalized, hypertension (weaned off 3 antihypertensive drugs), edema and proteinuria improved. Additionally, exposure to mycophenolic acid (MPA), active metabolite of mycophenolate, determined by area under the concentration-time curve of MPA was low throughout, despite significant dosing escalation. CONCLUSIONS: This case report demonstrates that individualized therapy guided by therapeutic drug monitoring might be needed in patients with nephrotic range proteinuria treated with eculizumab and mycophenolate (mofetil and sodium), an important finding that needs to be considered for further treatment trials.

Paediatric-to-adult transition experience in vasculitis: report of a model of care and outcomes.

OBJECTIVES: Transitioning from paediatric to adult care can be challenging. Whereas transition models of care have been shared in some rheumatological conditions, reported experience in vasculitis is lacking. METHODS: Retrospective chart review of adolescents aged 16-18 years assessed at the vasculitis transition clinic by paediatric and adult rheumatologists, and then scheduled for follow-up at the Adult Vasculitis Clinic (Toronto, Canada) from January 2013 until May 2020. RESULTS: Twenty-eight patients were seen at the transition clinic and included. Mean age at transition was 17 years and 11 (± SD 2) months, with a mean follow up from diagnosis of 32 (± 24) months. Most patients had ANCA-associated vasculitis (N=19, 39%), followed by Takayasu's arteritis (N=4, 14%); all but one were in remission at the time of transition. Twenty-six (93%) patients showed up for their first booked adult visit (two did not, were called and rebooked), after a mean of 4 (± 2) months after transition clinic. Subsequently, two patients missed 1 appointment, and three missed ≥ 2 appointments; only one (4%) stopped coming, while in remission for >2 years post-transition. Five (18%) patients were identified to have medication non-adherence after transition. With a mean follow up post-transition of 32 (± 25) months, 7 (25%) patients had minor and five (18%) had major relapses, at a mean of 17 (± 9) and 25 (± 15) months post-transition, respectively (compared to 12 (43%) and 9 (32%) prior to transition). At their last visit, all were in remission, 18 (64%) off glucocorticoids, and damage had remained stable. CONCLUSIONS: This model of care of vasculitis transition clinic resulted in favourable outcomes, as reflected by continuity of follow-up, and no increased risk of relapse.

Wide variation in glucocorticoid dosing in paediatric ANCA-associated vasculitis with renal disease: a paediatric vasculitis initiative study.

OBJECTIVES: High-dose glucocorticoids for remission-induction of ANCA-associated vasculitis are recommended and commonly used in adults, but recent studies suggest lower glucocorticoid doses can reduce toxicity without reducing efficacy. No paediatric-specific data exists to inform optimal glucocorticoid dosing in paediatric ANCA-associated vasculitis (pAAV). Our objectives were to describe glucocorticoid use in pAAV-related renal disease, and to explore associations between glucocorticoid dose, baseline patient characteristics and 12-month outcomes. METHODS: Youth <18 years with pAAV, biopsy-confirmed pauci-immune glomerulonephritis and 12-month follow-up data were included from an international paediatric vasculitis registry. Presenting features and 12-month outcomes (eGFR, glucocorticoid-related adverse effects), were compared between patients receiving no, low-moderate (≤90mg/kg) and high (>90mg/kg) cumulative intravenous methylprednisolone (IVMP), and low (<0.5mg/kg/day prednisone equivalent), moderate (0.5-1.5mg/kg/day) and high (>1.5mg/kg/day) starting doses of oral glucocorticoids. RESULTS: Among 131 patients (101 granulomatosis with polyangiitis, 30 microscopic polyangiitis), 27 (21%) received no IVMP, 64 (49%) low-moderate and 29 (22%) high-dose IVMP, while 9 (7%) received low, 75 (57%) moderate and 47 (36%) high initial doses of oral glucocorticoids. Renal failure at diagnosis (p=0.022) and plasmapheresis use (p=0.0001) were associated with high-dose IVMP. Rates of glucocorticoid-related adverse effects ranged from 15-31% across dose levels, and glucocorticoid dosing did not associate with 12-month outcomes. CONCLUSIONS: Glucocorticoid dosing for pAAV-related renal disease was highly variable, and rates of adverse effects were high across all dosing groups. A significant proportion of patients received oral glucocorticoid or IVMP doses that were discordant with current adult guidelines. Higher glucocorticoid doses did not associate with improved outcomes.

Implementing a fluid volume management program to decrease intra-dialytic hypotensive events in a paediatric in-centre haemodialysis unit: a quality improvement project.

BACKGROUND: Intra-dialytic hypotension (IDH) is the most common serious adverse event in paediatric haemodialysis (HD). Repeated IDH results in chronic multi-organ damage and increased mortality. At the Hospital for Sick Children, Toronto, retrospective data from all in-centre HD sessions revealed frequently occurring IDH events (16.5 ± 5.6% of HD sessions per week). Based on literature review and clinical expertise, fluid volume management was selected as a potential modifiable risk factor to decrease IDH. Root causes identified as contributing to IDH were incorporated into a Paediatric haemodialysis fluid volume management (PedHDfluid) program using the Model for Improvement methodology including rapid cycles of change. METHODS: Multiple measures were evaluated including (i) Outcome: IDH events per number of HD sessions per week; (ii) Process: number of changes to estimated dry weight per number of HD sessions per week; (iii) Balancing: time spent on dry weight meeting per week. Data was analysed using statistical process control charts. We aimed to decrease IDH in our dialysis unit to < 10% of HD sessions per week over a 6-month period by implementing a PedHDfluid program, including a multifaceted dry weight assessment protocol, multidisciplinary meetings and electronic health records "Dry Weight Evaluation flow sheet/synopsis". RESULTS: The project resulted in a decline in IDH events from 16.5 ± 5.6% to 8.8 ± 3.3% of HD sessions per week. More frequent dry weight changes and increased awareness of fluid removal goals were noted. CONCLUSIONS: A multidisciplinary approach including regular assessment, guidelines and systematic discussion, with an embedded electronic health record assessment and data gathering tool may sustainably reduce IDH events. A higher resolution version of the Graphical abstract is available as Supplementary information.

Assessing nephrology competence in general paediatrics-A survey of general paediatricians, paediatric nephrologists, residents, and program directors.

Objective: The objective of this study was to identify nephrology topics of lowest perceived competency and importance for general paediatricians. Methods: Surveys were distributed to general paediatricians, paediatric residents, paediatric residency program directors, and paediatric nephrologists. Perceived importance and competence were rated on a 5-point Likert scale. Means and 95% confidence intervals were calculated. Results: Mean perceived competency from general paediatricians across all nephrology domains was 3.0, 95%CI (2.9 to 3.1) and mean importance was 3.2, 95%CI (3.1 to 3.3). Domains scoring below the means for competence and importance, respectively were kidney stones (2.5, 95%CI [2.2 to 2.7]) and 2.6, 95%CI [2.3 to 2.8]), acute kidney injury (2.5, 95%CI [2.2 to 2.8] and 2.4, 95%CI [2.1 to 2.8]), chronic kidney disease (1.9, 95%CI [1.7 to 2.2] and 2.1, 95%CI [1.8 to 2.4]), tubular disorders (1.8, 95%CI [1.6 to 2.0] and 2.0, 95%CI [1.8 to 2.3]), and kidney transplant (1.6, 95%CI [1.4 to 1.8] and 1.7, 95%CI [1.4 to 1.9]). Residents, program directors, and paediatric nephrologists agreed that stones, chronic kidney disease, tubular disorders, and transplant were of lower importance. However, acute kidney injury was the domain with the largest discrepancy in perceived importance between residents (4.4, 95%CI [4.2 to 4.6]), nephrologists (4.2, 95%CI [3.8 to 4.6]), and program directors (4.2, 95%CI [3.7 to 4.7]) compared to general paediatricians ([2.4, 95%CI [2.1 to 2.8]; P<0.05). Conclusion: Paediatricians did not believe acute kidney injury was important to their practice, despite expert opinion and evidence of long-term consequences. Educational interventions must address deficits in crucial domains of renal health in paediatrics.

Impact of steroids and steroid-sparing agents on quality of life in children with nephrotic syndrome.

BACKGROUND: Steroids and/or steroid-sparing medications are commonly used for nephrotic syndrome treatment; however, the impact of these medications on health-related quality of life over time is not well described. METHODS: Longitudinal cohort is up to 5 years where children were assessed with baseline and annual Pediatric Quality of Life Inventory questionnaire. A mixed-effects linear regression determined differences in scores among children receiving steroids and/or steroid-sparing agents for at least 30 days compared with those not on medication at 1, 3, 6, and 12 months prior to assessment. RESULTS: Among 295 children, 64% were male, with a median age of 3.7 (interquartile range [IQR], 2.7, 5.9) years at diagnosis, and comprised 25% Europeans, 40% South Asians, and 8% East/Southeast Asians. Adjusted HRQOL scores were reduced among children taking steroids and steroid-sparing agents among 705 HRQOL measures (median 2 [IQR, 1, 3] per child). Compared to children without medication, steroid and steroid-sparing agent use up to 12 months prior to assessment were associated with an overall HRQOL drop of 3.17 (95% confidence interval [CI], - 5.25, - 1.08) and 3.18 (95% CI, - 5.24, - 1.12), respectively, after adjustment. Functioning domain scores were reduced by 4.41 points (95% CI, - 6.57, - 2.25) in children on steroids, whereas fatigue domain scores were reduced by 5.47 points (95% CI, - 9.28, - 1.67) in children on steroid-sparing agents after adjustment. CONCLUSIONS: HRQOL is consistently decreased in children receiving steroids and steroid-sparing agents, with differential effects on functioning and fatigue. Counseling families on possible effects of prolonged treatment periods is important in the management of childhood nephrotic syndrome.

Social vulnerability and COVID-19: A call to action for paediatric clinicians.

The COVID-19 pandemic has had dramatic effects on the lives of children globally. However, socially vulnerable children have been particularly impacted. Certain populations have increased vulnerabilities, including children and youth experiencing homelessness. Increased infection risk due to congregant living and challenges with physical distancing are contributing factors. An urgent need exists for a wholistic approach to care with unique cross-sectoral partnerships across disciplines. A recognition of the unintended consequence of the COVID-19 pandemic on this population is urgently required by all those supporting children. Families should receive direct support in clinical settings to identify their social needs. Partnership with community agencies and advocacy for appropriate isolation facilities for patients experiencing homelessness are critical.

Hemodialysis Catheters in Infants: A Retrospective Single-Center Cohort Study.

PURPOSE: Evaluate technical aspects and outcomes of insertion/maintenance of hemodialysis (HD) central venous catheter (CVC) during infancy. MATERIALS AND METHODS: Single-center retrospective study of 29 infants who underwent 49 HD-CVC insertions between 2002 and 2016. Demographics, procedural, and post-procedural details, interventional radiology (IR) maintenance procedures, technical modifications, complications, and outcomes were evaluated. Technical adjustments during HD-CVC placement to adapt catheter length to patient size were labeled "modifications." CVCs requiring return visit to IR were called IR-maintenance procedures. Mean age and weight at HD-CVC insertion were 117 days and 4.9 kg. RESULTS: Of the 29 patients, 13 (45%) required renal-replacement-therapy (RRT) as neonates, 10 (34%) commenced RRT with peritoneal dialysis (PD), and 19 (66%) with HD. Fifteen nontunneled and 34 tunneled HD-CVCs were inserted while patients were ≤1 year. Technical modifications were required placing 25/49 (51%) HD-CVCs: 5/15 (33%) nontunneled and 20/34 (59%) tunneled catheters (P = .08). Patients underwent ≤6 dialysis-cycles/patient during infancy (mean 2.3), and a mean of 4.1 and 49 HD-sessions/catheter for nontunneled and tunneled HD-CVCs, respectively. Mean primary and secondary device service, and total access site intervals for tunneled HD-CVCs were 75, 115, and 201 days, respectively. A total of 26 of 49 (53%) patients required IR-maintenance procedures. Nontunneled lines had greater catheter-related bloodstream infections per 1,000 catheter-days than tunneled HD-CVCs (9.25 vs. 0.85/1,000 catheter days; P = .02). Nineteen patients (65%) survived over 1 year. At final evaluation (December 2017): 8/19 survived transplantation, 5/19 remained on RRT, 2/19 completely recovered, 1/19 lost to follow-up, and 3 died at 1.3, 2, and 10 years. CONCLUSIONS: Placement/maintenance of HD-CVCs in infants pose specific challenges, requiring insertion modifications, and IR-maintenance procedures to maintain function.

Quality improvement in pediatric nephrology-a practical guide.

Improving quality of care delivery is an important focus for all practicing physicians. Frontline clinicians are in a great position to identify clinical problems and find innovative solutions. The current review describes the method used for quality improvement based on the Model for Improvement, a structural framework to guide improvement work. At its basis are three fundamental questions: What are we trying to accomplish? How will I know that a change will lead to improvement? And what changes could we make that will result in improvement? This preparation phase aims to identify and understand the problem, choose an intervention, and determine reliable measures to gauge improvement. The intervention is then tested using PLAN-DO-STUDY-ACT (PDSA) cycles, an iterative approach to systematically improve processes and outcomes. PLAN focuses on defining the goal of the cycle and describing in details what will be done. DO concentrates on the concrete application of the plan. STUDY focuses on data analyses as ACT identifies lessons learned from the cycle and orientate the goals of the following PDSA cycle. Learning from each cycle, developing an interdisciplinary team and repeated interventions are core principles involved in implementing a sustainable quality improvement program. The Model for Improvement will be illustrated by a common quality problem in pediatric nephrology.

Idiopathic nephrotic syndrome in children.

The incidence of idiopathic nephrotic syndrome (NS) is 1·15-16·9 per 100 000 children, varying by ethnicity and region. The cause remains unknown but the pathogenesis of idiopathic NS is thought to involve immune dysregulation, systemic circulating factors, or inherited structural abnormalities of the podocyte. Genetic risk is more commonly described among children with steroid-resistant disease. The mainstay of therapy is prednisone for the vast majority of patients who are steroid responsive; however, the disease can run a frequently relapsing course, necessitating the need for alternative immunosuppressive agents. Infection and venous thromboembolism are the main complications of NS with also increased risk of acute kidney injury. Prognosis in terms of long-term kidney outcome overall is excellent for steroid-responsive disease, and steroid resistance is an important determinant of future risk of chronic or end-stage kidney disease.

Prevalence of Asthma and Allergies and Risk of Relapse in Childhood Nephrotic Syndrome: Insight into Nephrotic Syndrome Cohort.

OBJECTIVE: To determine the lifetime prevalence of allergies in childhood nephrotic syndrome, the seasonality of presentation and relapses, and the impact of allergies on subsequent relapses. STUDY DESIGN: In a longitudinal cohort of children with nephrotic syndrome (ages 1-18 years), assessment for allergic diseases was conducted using the validated and modified version of the International Study of Asthma and Allergies in Childhood questionnaire at enrollment. Outcomes included frequently relapsing nephrotic syndrome, relapse rates, and the relapse-free duration after initial steroid therapy. RESULTS: Among 277 participants, the majority were male (65%) with a median age of 3.7 years (IQR 2.8-5.8) at presentation. A total of 64% reported lifetime allergies with 20% having asthma, 33% wheezing, 27% eczema, and 24% rhinitis. Over 3.3 years of follow-up, presence of asthma and allergies was not associated with frequently relapsing nephrotic syndrome (OR 1.20; 95% CI 0.60, 2.40), higher relapse rates (relative risk 0.95; 95% CI 0.71, 1.27), or risk of first relapse (hazard ratio 1.10; 95% CI 0.83, 1.47) compared with those with no history of allergic diseases. There was also no seasonal variation evident at initial presentation or frequency of relapses. CONCLUSIONS: Two-thirds of children with nephrotic syndrome at presentation have allergic symptoms and asthma; however, neither are associated with an increased frequency of relapses.

Kidney disease and organ transplantation in methylmalonic acidaemia.

OBJECTIVES: MMA is associated with chronic tubulointerstitial nephritis and a progressive decline in GFR. Optimal management of these children is uncertain. Our objectives were to document the pre-, peri-, and post-transplant course of all children with MMA who underwent liver or combined liver-kidney transplant in our centers. DESIGN AND METHODS: Retrospective chart review of all cases of MMA who underwent organ transplantation over the last 10 years. RESULTS: Five children with MMA underwent liver transplant (4/5) and combined liver-kidney transplant (1/5). Three were Mut0 and two had a cobalamin B disorder. Four of five were transplanted between ages 3 and 5 years. Renal dysfunction prior to transplant was seen in 2/5 patients. Post-transplant (one liver transplant and one combined transplant) renal function improved slightly when using creatinine-based GFR formula. We noticed in 2 patients a big discrepancy between creatinine- and cystatin C-based GFR calculations. One patient with no renal disease developed renal failure post-liver transplantation. Serum MMA levels have decreased in all to <300 µmol/L. Four patients remain on low protein diet, carnitine, coenzyme Q, and vitamin E post-transplant. CONCLUSIONS: MMA is a complex metabolic disorder. Renal disease can continue to progress post-liver transplant and close follow-up is warranted. More research is needed to clarify best screening GFR method in patients with MMA. Whether liver transplant alone, continued protein restriction, or the addition of antioxidants post-transplant can halt the progression of renal disease remains unclear.

Association of low birth weight and prematurity with clinical outcomes of childhood nephrotic syndrome: a prospective cohort study.

BACKGROUND: Low birth weight (LBW)/prematurity have been proposed as risk factors for the development of kidney disease in adulthood. Whether there is an association between LBW/prematurity and poor renal outcomes in childhood onset nephrotic syndrome remains unknown. METHODS: Children with nephrotic syndrome diagnosed between 1 and 18 years of age were followed prospectively from 1996 to 2016 at The Hospital for Sick Children (N = 377). LBW/prematurity was defined as birth weight < 2500 g or gestational age < 36 weeks. Normal birth weight (NBW) was defined as birth weight ≥ 2500 g. Measures evaluating clinical course of nephrotic syndrome include initial steroid-resistant nephrotic syndrome (SRNS), time to first relapse, and frequently relapsing nephrotic syndrome. Kaplan-Meier survival analysis, logistic regression, and Cox proportional hazards regression were used to determine the association of LBW/prematurity with clinical outcomes. RESULTS: Median birth weights in LBW/premature (n = 46) and NBW (n = 331) children were 2098 g (interquartile range [IQR] 1700-2325 g) and 3317 g (IQR 2977-3685 g), respectively. Odds of having SRNS were 3.78 (95% confidence interval [CI] 1.28-11.21) times higher among LBW/premature children than NBW children. An 8% decrease in odds of developing SRNS was observed for every 100 g increase in birth weight (adjusted odds ratio [OR] 0.92; 95% CI 0.86-0.98). Median time to first relapse did not differ (hazard ratio [HR] 0.89; 95% CI 0.53-1.16). CONCLUSIONS: LBW/premature children were more likely to develop SRNS but did not have a difference in time to first relapse with NBW children. Understanding the impact and mechanism of birth weight and steroid-resistant disease needs further study.

Impact of Adjuvant Urinary Diversion versus Valve Ablation Alone on Progression from Chronic to End Stage Renal Disease in Posterior Urethral Valves: A Single Institution 15-Year Time-to-Event Analysis.

PURPOSE: Long-term progression to end stage renal disease of valve ablation alone vs ablation followed by additional urinary diversion were compared among children with stage 3 chronic kidney disease due to posterior urethral valves. MATERIALS AND METHODS: We performed a retrospective study of children with posterior urethral valves and stage 3 chronic kidney disease treated at a single institution between 1986 and 2011. The 3 treatment groups were classified as group 1-valve ablation alone, group 2-ablation plus subsequent vesicostomy and group 3-ablation followed by ureterostomies and/or pyelostomies. Baseline demographic characteristics were analyzed. Statistical analyses compared the incidence of time to end stage renal disease among the intervention groups using the Fisher-Freeman-Halton exact test and Kaplan-Meier analysis with the log rank test. Cox regression was used to determine predictors of end stage renal disease progression. RESULTS: A total of 40 eligible patients were included in the study (group 1-14 patients, group 2-13 patients, group 3-13 patients). Baseline characteristics and post-intervention estimated glomerular filtration rate revealed no significant between-group differences. A statistically significant difference in progression to end stage renal disease was noted within 1 year after diagnosis of stage 3 chronic kidney disease among the treatment groups (log rank test p=0.02). However, cumulative end stage renal disease incidence at 15-year followup showed no statistical difference (log rank test p=0.628). Cox regression analysis determined that bilateral renal dysplasia (HR 2.76, 95% CI 1.21-6.30) and estimated glomerular filtration rate 60 ml/minute/1.73 m2 or greater after intervention (HR 0.23, 95% CI 0.09-0.61) were predictive of the likelihood of progression to end stage renal disease. CONCLUSIONS: Urinary diversion following valve ablation in children with stage 3 chronic kidney disease associated with posterior urethral valves may temporarily delay progression to end stage renal disease. However, no long-term benefit was noted from diversion in the ultimate incidence of end stage renal disease, suggesting that these interventions should be seen as a temporizing measure. Bilateral renal dysplasia and post-intervention estimated glomerular filtration rate are independent variables predicting overall chronic kidney disease progression.

Pathogenesis and treatment of ANCA-associated vasculitis-a role for complement.

The antineutrophil cytoplasm autoantibody (ANCA)-associated vasculitides (AAV), although rare in childhood, can have devastating effects on affected organs, especially the kidney. In this review we present an update on the pathogenesis and treatment of ANCA vasculitis, with a particular emphasis on the role of the alternative pathway of complement. The rationale and evidence for the current treatment strategies are summarized. Targeting the activation of neutrophils by the anaphylatoxin C5a may serve as an additional therapeutic strategy, however the results of clinical studies are awaited.