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.

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.

Treatment of Childhood-onset Proliferative Lupus Nephritis in the 21st Century: A Call to Catch Up With the Evidence

Proliferative lupus nephritis (PLN) is associated with significant morbidity, mortality, and kidney failure, especially in childhood-onset PLN (cPLN). Therefore, it is important to treat it promptly and aggressively, while being cognizant of the risk-benefit ratio and side effects of therapies.

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.

Vascular endothelial cells evade complement-mediated membrane injury via Weibel-Palade body mobilization

BACKGROUND

Defective complement inhibition can lead to the formation of membrane attack complexes (MAC; C5b-9) on the plasma membranes of vascular endothelial cells, resulting in injury that drives the progression of thrombotic microangiopathy (TMA), a key pathology in kidney disease.

OBJECTIVE/METHODS

We examined the response of human endothelial cells to complement-mediated damage using blood outgrowth endothelial cells (BOECs) derived from healthy donors. BOECs were sensitized to complement factors present in normal human serum to induce the formation of C5b-9 on their plasma membranes.

RESULTS

This triggered an expected abrupt rise in intracellular Ca2+ reflecting membrane leakage. Remarkably, while intracellular Ca2+ remained elevated, membrane leakage ceased within 30 minutes, and cells did not show significant death. Extensive mobilization of Weibel-Palade bodies (WPBs) was observed along with secretion of von Willebrand factor (VWF). The potential role of WPBs and VWF in mitigating complement-mediated damage was examined by comparing the effects of C5b-9 on BOECs derived from von Willebrand disease (VWD) patients expressing reduced amounts of VWF, lacking expression of functional VWF, or lacking both VWF and WPBs. BOECs lacking WPBs were not resistant to complement-mediated damage, but became resistant when transfected to express VWF (and thus WPBs).

CONCLUSION

We conclude that BOECs exposed to C5b-9 attack respond by mobilizing WPBs, which mitigate and repair damage by fusing with the plasma membrane. We propose that a similar cell-specific response may protect the vascular endothelium from complement-mediated damage in vivo.

Clinical Characteristics and Treatment Patterns of Children and Adults With IgA Nephropathy or IgA Vasculitis: Findings From the CureGN Study

Introduction

The Cure Glomerulonephropathy Network (CureGN) is a 66-center longitudinal observational study of patients with biopsy-confirmed minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, or IgA nephropathy (IgAN), including IgA vasculitis (IgAV). This study describes the clinical characteristics and treatment patterns in the IgA cohort, including comparisons between IgAN versus IgAV and adult versus pediatric patients.

Methods

Patients with a diagnostic kidney biopsy within 5 years of screening were eligible to join CureGN. This is a descriptive analysis of clinical and treatment data collected at the time of enrollment.

Results

A total of 667 patients (506 IgAN, 161 IgAV) constitute the IgAN/IgAV cohort (382 adults, 285 children). At biopsy, those with IgAV were younger (13.0 years vs. 29.6 years, P < 0.001), more frequently white (89.7% vs. 78.9%, P = 0.003), had a higher estimated glomerular filtration rate (103.5 vs. 70.6 ml/min per 1.73 m², P < 0.001), and lower serum albumin (3.4 vs. 3.8 g/dl, P < 0.001) than those with IgAN. Adult and pediatric individuals with IgAV were more likely than those with IgAN to have been treated with immunosuppressive therapy at or prior to enrollment (79.5% vs. 54.0%, P < 0.001).

Conclusion

This report highlights clinical differences between IgAV and IgAN and between children and adults with these diagnoses. We identified differences in treatment with immunosuppressive therapies by disease type. This description of baseline characteristics will serve as a foundation for future CureGN studies.

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.

A curious case of growth failure and hypercalcemia: Answers

BACKGROUND

Sarcoidosis is a multisystem granulomatous disease of unknown etiology that rarely presents in childhood. Here, we report a case of pediatric sarcoidosis, presenting with renal failure and hypercalcemia.

CASE DIAGNOSIS/TREATMENT

A previously well 14-year-old Caucasian boy was admitted to the Hospital for Sick Children, Canada, for hypertension and renal failure following work-up by his family physician for initial concerns of growth failure. On admission, his weight was 35 kg (<3rd percentile), his height was 148 cm (<<3rd percentile), and his blood pressure was 154/116 mmHg (>99th percentile for height). Laboratory findings showed elevated creatinine (218 umol/L), hypercalcemia (3.21 mmol/L), and normocytic anemia (hemoglobin 105 g/L). His further assessment showed a urinary concentrating defect with hypercalciuria (calcium/creatinine 1.76 mmol/mmol) and nephrocalcinosis on ultrasound. His eye examination showed uveitis with conjunctival biopsy remarkable for granulomas, which led to pursuit of a diagnosis of possible sarcoidosis. Angiotensin Angiotensin-converting enzyme was found to be high at 96 U/L, and he had a renal biopsy that was consistent with interstitial nephritis with granulomas. Treatment was started with prednisone leading to resolution of his hypercalcemia but persistence of his mild chronic kidney disease.

CONCLUSIONS

This case represents an atypical presentation of a rare pediatric disease and highlights the spectrum of renal manifestations and treatment options in sarcoidosis.

Nephrotic syndrome in infants and children: pathophysiology and management

Nephrotic syndrome is defined by nephrotic-range proteinuria (≥40 mg/m²/hour or urine protein/creatinine ratio ≥200 mg/mL or 3+ protein on urine dipstick), hypoalbuminaemia (<25 g/L) and oedema. This review focuses on the classification, epidemiology, pathophysiology, management strategies and prognosis of idiopathic nephrotic syndrome of childhood, and includes a brief overview of the congenital forms.

Hypertension in pediatric patients with chronic kidney disease: management challenges

In contrast to adults where hypertension is a leading cause of chronic kidney disease, in pediatrics, hypertension is predominantly a sequela, however, an important one that, like in adults, is likely associated with a more rapid decline in kidney function or progression of chronic kidney disease to end stage. There is a significant issue with unrecognized, or masked, hypertension in childhood chronic kidney disease. Recent evidence and, therefore, guidelines now suggest targeting a blood pressure of <50th percentile for age, sex, and height in children with proteinuria and chronic kidney disease. This often cannot be achieved by monotherapy and additional agents need to be added. Blockade of the renin angiotensin aldosterone system represents the mainstay of therapy, although often limited by the side effect of hyperkalemia. The addition of a diuretic, at least in the earlier stages of chronic kidney disease, might help mitigate this problem.

Successful Image-Guided Retrieval of an Embolized Fragment of a Fractured Haemodialysis Catheter Tip from the Pulmonary Artery

Background

Cuffed, double-lumen, tunneled haemodialysis catheters are a common means of vascular access in paediatric haemodialysis, particularly in infants. Haemodialysis catheter fracture with distal embolization is a rare complication.

Case Report

A 2-year-old boy was receiving chronic haemodialysis via a right internal jugular cuffed, double-lumen, tunneled haemodialysis catheter, inserted 3 months previously. He was asymptomatic and was incidentally found to have had embolization of a fractured catheter tip into a segmental branch of the left pulmonary artery. The catheter was replaced and the embolized fragment successfully retrieved, non-surgically, using an image-guided endovascular approach with a loop snare device.

Conclusion

Haemodialysis catheter fracture with distal embolization is a rare complication in both adults and children and is usually associated with prolonged use and catheter fatigue. Retrieval of the embolized fragment should always be attempted to prevent possible complications. Awareness of this potential complication is important to facilitate diagnosis and management.

The new histopathologic classification of ANCA-associated GN and its association with renal outcomes in childhood

BACKGROUND AND OBJECTIVES

A proposed histopathologic classification for ANCA-associated GN is predictive of long-term renal outcome in adult populations. This study sought to validate this system in a pediatric cohort.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a retrospective, single-center, cohort study of 40 children diagnosed and followed until their transition to adult care at one institution between 1987 and 2012. Renal biopsy specimens were reviewed by a pathologist blinded to patient outcome and were classified using the new histopathologic classification system of focal, crescentic, mixed, and sclerotic groups. Time to the composite outcome of CKD stages 3 and 4 (determined by eGFR with repeated creatinine measures using the Schwartz equation) or ESRD (defined as dialysis dependence or transplantation) were ascertained.

RESULTS

The study population consisted of 40 children (70% female), followed for a median of 2.4 years. The biopsy specimens were categorized as focal in 13 patients (32.5%), crescentic in 20 (50%), mixed in two (5%), and sclerotic in five (12.5%). Mixed and crescentic were combined for analyses. Survival analysis of time to the composite renal endpoint of at least 3 months of eGFR<60 ml/min per 1.73 m(2) or ESRD differed significantly among the three biopsy groups log-rank P<0.001), with an adjusted hazard ratio of 3.14 (95% confidence interval, 0.68 to 14.4) in the crescentic/mixed group and 23.6 (95% confidence interval, 3.9 to 144.2) in the sclerotic category compared with the focal category. The probability of having an eGFR>60 ml/min per 1.73 m(2) at 2 years was 100% for the focal, 56.5% for the crescentic/mixed, and 0% for the sclerotic biopsy categories.

CONCLUSIONS

This study showed the clinical utility of this histopathologic classification system and its ability to discriminate renal outcomes among children with ANCA GN.

Spectrum of complement-mediated thrombotic microangiopathies: pathogenetic insights identifying novel treatment approaches

Thrombotic microangiopathy (TMA) is a rare but severe disorder characterized by endothelial cell activation and thrombus formation. It manifests with the triad of hemolytic anemia, thrombocytopenia, and organ failure. Prompt diagnosis and treatment initiation are crucial for long-term outcome. TMA often manifests subsequent to infectious events, of which (enterohemorrhagic) Escherichia coli is the most frequently reported. TMA also occurs on the background of genetic/autoimmune defects in the complement system (atypical hemolytic uremic syndrome [aHUS]) and underlying conditions, such as pregnancy, transplantation, drugs, other glomerulopathies, vasculitides, or metabolic defects. Complement activation or defects in its regulation have now been described in an increasing number of acquired diseases with TMA. Coinciding with this expanding spectrum of complement-mediated diseases, the question arises which patients might benefit from a complement-targeted therapy. Success of therapy depends on the individual contribution of complement activation in disease pathogenesis. The advent of eculizumab, a monoclonal antibody that blocks terminal complement activation, has markedly improved outcome and quality of life in patients with aHUS. This review discusses the contribution of complement and highlights its complex interaction with inflammation, coagulation, and the endothelium. Treatment experiences focusing on eculizumab therapy are discussed in detail across the emerging spectrum of complement-mediated thrombotic microangiopathies.

Hyperuricemia is associated with hypertension, obesity, and albuminuria in children with chronic kidney disease

OBJECTIVE

To assess the prevalence and associations of hyperuricemia in a cohort of pediatric patients with chronic kidney disease (CKD).

STUDY DESIGN

This was an observational cross-sectional study of clinical and laboratory data in pediatric patients being followed in a nephrology clinic. All patients with CKD were included. ORs and risk estimates of having stage III-V CKD (defined as an estimated glomerular filtration rate [eGFR] <60 mL/min/1.73 m(2)) with hyperuricemia were calculated. The relationships among eGFR, body mass index (BMI), and hyperuricemia were estimated using both correlation and regression models.

RESULTS

A total of 116 children (61% male), aged 0.4-17 years, were included in the analysis. The prevalence of hyperuricemia in those with an eGFR <60 mL/min/1.73 m(2) was 70%. Children with hyperuricemia were more likely to have an eGFR <60 mL/min/1.73 m(2) than those with a normal urate level (OR, 4.6) and were more likely to be hypertensive (OR, 2.1). Hyperuricemia was significantly associated with increased BMI, albuminuria, renal dysfunction with reduced eGFR, and hypertension. Significant linear relationships between eGFR and urate (P = .0001) and between BMI and urate (P = .0001) were detected.

CONCLUSIONS

Hyperuricemia is common in pediatric patients with CKD and is associated with renal dysfunction, hypertension, obesity, and albuminuria. Future prospective studies should be undertaken to further assess the role of hyperuricemia in pediatric patients with CKD.