The Study of the Epidemiology of Pediatric Hypertension Registry (SUPERHERO): Rationale and Methods.

Despite increasing prevalence of hypertension in youth and high adult cardiovascular mortality rates, the long-term consequences of youth-onset hypertension remain unknown. This is due to limitations of prior research such as small sample sizes, reliance on manual record review, and limited analytic methods that did not address major biases. The Study of the Epidemiology of Pediatric Hypertension (SUPERHERO) is a multisite retrospective Registry of youth evaluated by subspecialists for hypertension disorders. Sites obtain harmonized electronic health record data using standardized biomedical informatics scripts validated with randomized manual record review. Inclusion criteria are index visit for International Classification of Diseases Diagnostic Codes, 10th Revision (ICD-10 code)-defined hypertension disorder ≥January 1, 2015 and age <19 years. We exclude patients with ICD-10 code-defined pregnancy, kidney failure on dialysis, or kidney transplantation. Data include demographics, anthropomorphics, U.S. Census Bureau tract, histories, blood pressure, ICD-10 codes, medications, laboratory and imaging results, and ambulatory blood pressure. SUPERHERO leverages expertise in epidemiology, statistics, clinical care, and biomedical informatics to create the largest and most diverse registry of youth with newly diagnosed hypertension disorders. SUPERHERO's goals are to (i) reduce CVD burden across the life course and (ii) establish gold-standard biomedical informatics methods for youth with hypertension disorders.

Blood Pressure Outcomes in NICU-Admitted Infants with Neonatal Hypertension: A Pediatric Nephrology Research Consortium Study.

OBJECTIVE: To describe the blood pressure outcomes of infants admitted to the neonatal intensive care unit (NICU) with idiopathic (nonsecondary) hypertension (HTN) who were discharged on antihypertensive therapy. STUDY DESIGN: Retrospective, multicenter study of 14 centers within the Pediatric Nephrology Research Consortium. We included all infants with a diagnosis of idiopathic HTN discharged from the NICU on antihypertensive treatment. The primary outcome was time to discontinuation of antihypertensive therapy, grouped into (≤6 months, >6 months to 1 year, and >1 year). Comparisons between groups were made with χ2 tests, Fisher's exact tests, and ANOVA. RESULTS: Data from 118 infants (66% male) were included. Calcium channel blockers were the most prescribed class of antihypertensives (56%) in the cohort. The percentages remaining on antihypertensives after NICU discharge were 60% at 6 months, 26% at 1 year, and 7% at 2 years. Antenatal steroid treatment was associated with decreased likelihood of antihypertensive therapy >1 year after discharge. CONCLUSIONS: This multicenter study reports that most infants admitted to the NICU diagnosed with idiopathic HTN will discontinue antihypertensive treatment by 2 years after NICU discharge. These data provide important insights into the outcome of neonatal HTN, but should be confirmed prospectively.

Antibody-mediated rejection in pediatric kidney transplant recipients: A report from the Pediatric Nephrology Research Consortium.

BACKGROUND: Antibody-mediated rejection (AMR) is a major cause of kidney allograft loss. There is a paucity of large-scale pediatric-specific data regarding AMR treatment outcomes. METHODS: Data were obtained from 14 centers within the Pediatric Nephrology Research Consortium. Kidney transplant recipients aged 1-18 years at transplant with biopsy-proven AMR between 2009 and 2019 and at least 12 months of follow-up were included. The primary outcome was graft failure or an eGFR <20 mL/min/1.73 m2 at 12 months following AMR treatment. AMR treatment choice, histopathology, and DSA class were also examined. RESULTS: We reviewed 123 AMR episodes. Median age at diagnosis was 15 years at a median 22 months post-transplant. The primary outcome developed in 27.6%. eGFR <30 m/min/1.73 m2 at AMR diagnosis was associated with a 5.6-fold higher risk of reaching the composite outcome. There were no significant differences in outcome by treatment modality. Histopathology scores and DSA class at time of AMR diagnosis were not significantly associated with the primary outcome. CONCLUSIONS: In this large cohort of pediatric kidney transplant recipients with AMR, nearly one-third of patients experienced graft failure or significant graft dysfunction within 12 months of diagnosis. Poor graft function at time of diagnosis was associated with higher odds of graft failure.

Age of Onset and Disease Course in Biopsy-Proven Minimal Change Disease: An Analysis From the Cure Glomerulonephropathy Network.

RATIONALE & OBJECTIVE: Adolescent- and adult-onset minimal change disease (MCD) may have a clinical course distinct from childhood-onset disease. We characterized the course of children and adults with MCD in the Cure Glomerulonephropathy Network (CureGN) and assessed predictors of rituximab response. STUDY DESIGN: Prospective, multicenter, observational study. STUDY PARTICIPANTS: CureGN participants with proven MCD on biopsy. EXPOSURE: Age at disease onset, initiation of renin-angiotensin-aldosterone system (RAAS) blockade, and immunosuppression including rituximab during the study period. OUTCOME: Relapse and remission, change in estimated glomerular filtration rate (eGFR), and kidney failure. ANALYTICAL APPROACH: Remission and relapse probabilities were estimated using Kaplan-Meier curves and gap time recurrent event models. Linear regression models were used for the outcome of change in eGFR. Cox proportional hazards models were used to estimate the association between rituximab administration and remission. RESULTS: The study included 304 childhood- (≤12 years old), 49 adolescent- (13-17 years old), and 201 adult- (≥18 years) onset participants with 2.7-3.2 years of follow-up after enrollment. Children had a longer time to biopsy (238 vs 23 and 36 days in adolescent- and adult-onset participants, respectively; P<0.001) and were more likely to have received therapy before biopsy. Children were more likely to be treated with immunosuppression but not RAAS blockade. The rate of relapse was higher in childhood- versus adult-onset participants (HR, 1.69 [95% CI, 1.29-2.21]). The probability of remission was also higher in childhood-onset disease (HR, 1.33 [95%CI, 1.02-1.72]). In all groups eGFR loss was minimal. Children were more likely to remit after rituximab than those with adolescent- or adult-onset disease (adjusted HR, 2.1; P=0.003). Across all groups, glucocorticoid sensitivity was associated with a greater likelihood of achieving complete remission after rituximab (adjusted HR, 2.62; P=0.002). LIMITATIONS: CureGN was limited to biopsy-proven disease. Comparisons of childhood to nonchildhood cases of MCD may be subject to selection bias, given that childhood cases who undergo a biopsy may be limited to patients who are least responsive to initial therapy. CONCLUSIONS: Among patients with MCD who underwent kidney biopsy, there were differences in the course (relapse and remission) of childhood-onset compared with adolescent- and adult-onset disease, as well as rituximab response. PLAIN-LANGUAGE SUMMARY: Minimal change disease is a biopsy diagnosis for nephrotic syndrome. It is diagnosed in childhood, adolescence, or adulthood. Patients and clinicians often have questions about what to expect in the disease course and how to plan therapies. We analyzed a group of patients followed longitudinally as part of the Cure Glomerulonephropathy Network (CureGN) and describe the differences in disease (relapse and remission) based on the age of onset. We also analyzed rituximab response. We found that those with childhood-onset disease had a higher rate of relapse but also have a higher probability of reaching remission when compared with adolescent- or adult-onset disease. Children and all steroid-responsive patients are more likely to achieve remission after rituximab.

NSAID-associated acute kidney injury in hospitalized children - a prospective Pediatric Nephrology Research Consortium study.

BACKGROUND: Acute kidney injury (AKI) in children has serious short-term and long-term consequences. We sought 1) to prospectively describe NSAID-associated AKI in hospitalized children; 2) to determine if NSAID-associated AKI was more severe in younger children < 5 years; and 3) to follow outcomes after hospitalization for NSAID-associated AKI. METHODS: This was a prospective, multi-center study in hospitalized children 1 month to 18 years. Parents/guardians were given a brief questionnaire to determine the dosing, duration, and type of NSAIDs given. Kidney Disease: Improving Global Outcomes (KDIGO) serum creatinine criteria were used to stage AKI severity. Patients with other causes of AKI were excluded (e.g., other nephrotoxins, sepsis, malignancy, etc.). RESULTS: We identified 25 patients with NSAID-associated AKI, accounting for 3.1% of AKI. All 25 had AKI upon hospital presentation. The median age was 15.5 years, and 20/25 (80%) had volume depletion. Median duration of NSAID use was 2 days, and 63% of patients took the normal recommended NSAID dose. Median hospital length of stay was 4 days, and none required dialysis. At the most recent estimated glomerular filtration rate (eGFR) after discharge (available in 17/25 patients), only 4/17 (24%) had eGFR ≥ 90 ml/min/1.73 m2, and 13/17 (76%) had eGFR 60 to < 90 ml/min/1.73 m2, indicative of abnormal kidney function. CONCLUSIONS: NSAID-associated AKI usually occurs with recommended NSAID dosing in the setting of dehydration. Follow-up after AKI showed a substantial rate of CKD. Therefore, we recommend that NSAIDs should not be used in dehydrated children. A higher resolution version of the Graphical abstract is available as Supplementary information.

Acute kidney injury requiring kidney replacement therapy in childhood lupus nephritis: a cohort study of the Pediatric Nephrology Research Consortium and Childhood Arthritis and Rheumatology Research Alliance.

BACKGROUND: Acute kidney injury (AKI) is common in lupus nephritis (LN) and a risk factor for development of chronic kidney disease. In adults with LN, AKI severity correlates with the incidence of kidney failure and patient survival. Data on AKI outcomes in children with LN, particularly those requiring kidney replacement therapy (KRT), are limited. METHODS: A multicenter, retrospective cohort study was performed in children diagnosed between 2010 and 2019 with LN and AKI stage 3 treated with dialysis (AKI stage 3D). Descriptive statistics were used to characterize demographics, clinical data, and kidney biopsy findings; treatment data for LN were not included. Logistic regression was used to examine the association of these variables with kidney failure. RESULTS: Fifty-nine patients (mean age 14.3 years, 84.7% female) were identified. The most common KRT indications were fluid overload (86.4%) and elevated blood urea nitrogen/creatinine (74.6%). Mean follow-up duration was 3.9 ± 2.9 years. AKI recovery without progression to kidney failure occurred in 37.3% of patients. AKI recovery with later progression to kidney failure occurred in 25.4% of patients, and there was no kidney recovery from AKI in 35.6% of patients. Older age, severe (> 50%) tubular atrophy and interstitial fibrosis, and National Institutes of Health (NIH) chronicity index score > 4 on kidney biopsy were associated with kidney failure. CONCLUSIONS: Children with LN and AKI stage 3D have a high long-term risk of kidney failure. Severe tubular atrophy and interstitial fibrosis at the time of AKI, but not AKI duration, are predictive of kidney disease progression. A higher resolution version of the Graphical abstract is available as Supplementary information.

White Coat Hypertension Persistence in Children and Adolescents: The Pediatric Nephrology Research Consortium Study.

OBJECTIVES: To determine whether youth with white coat hypertension on initial ambulatory blood pressure monitoring (ABPM) continue to demonstrate the same pattern on repeat ABPM. STUDY DESIGN: Retrospective longitudinal cohort study of patients referred for high blood pressure (BP) and diagnosed with white coat hypertension by ABPM who had follow-up ABPM 0.5-4.6 years later at 11 centers in the Pediatric Nephrology Research Consortium. We classified ABPM phenotype using the American Heart Association guidelines. At baseline, we classified those with hypertensive BP in the clinic as "stable white coat hypertension," and those with normal BP as "intermittent white coat hypertension." We used multivariable generalized linear mixed effect models to estimate the association of baseline characteristics with abnormal ABPM phenotype progression. RESULTS: Eighty-nine patients met the inclusion criteria (median age, 13.9 years; 78% male). Median interval time between ABPM measurements was 14 months. On follow-up ABPM, 61% progressed to an abnormal ABPM phenotype (23% ambulatory hypertension, 38% ambulatory prehypertension). Individuals age 12-17 years and those with stable white coat hypertension had greater proportions progressing to either prehypertension or ambulatory hypertension. In the multivariable models, baseline wake systolic BP index ≥0.9 was significantly associated with higher odds of progressing to ambulatory hypertension (OR 3.07, 95% CI 1.02-9.23). CONCLUSIONS: The majority of the patients with white coat hypertension progressed to an abnormal ABPM phenotype. This study supports the 2017 American Academy of Pediatrics Clinical Practice Guideline's recommendation for follow-up of ABPM in patients with white coat hypertension.

The scope of treatment of pediatric IgA vasculitis nephritis and its outcome: a Pediatric Nephrology Research Consortium study.

BACKGROUND: IgA vasculitis (IgAV) is the most common type of vasculitis in children. There is a lack of consensus for management of significant IgAV nephritis (IgAVN). This study was designed to identify the most used treatment options and describe their efficacy. METHODS: This is a multicenter retrospective study of children age 1-21 years with IgAVN who were managed for at least 6 months by a nephrologist. Subjects with at least microscopic hematuria and proteinuria and/or decreased kidney function were enrolled. Kidney outcome was assessed by eGFR and urine protein/creatinine (UPC) ratios at 2-4 weeks, 3, 6, and 12 months post-diagnosis. RESULTS: A total of 128 subjects with median age of 7 years (range 2-18) were included. Of these, 69 subjects had kidney biopsy with crescents detected in 53%. AKI (P = 0.039), nephrosis (P = 0.038), and crescents on biopsy (P = 0.013) were more likely in older patients. Patients with UPC > 1 mg/mg were more likely to get a kidney biopsy (P < 0.001) and to be treated with steroids ± immunosuppressive (IS) agents (P = 0.001). Sixty-six percent of patients were treated with steroids and/or IS agents for variable durations. Anti-metabolite agents were the most common IS agents used with variability in dosing and duration. At 12 months, most subjects had a normal eGFR (79%) (median 123, range 68-207 mL/min/1.73 m2) and no proteinuria (median UPC 0.15, range 0.01-4.02 mg/mg). CONCLUSIONS: IS agents are frequently used in managing IgAVN associated with heavy proteinuria, nephrosis, and/or AKI. Prospective studies are needed to determine indications and needed duration of IS therapy. A higher resolution version of the Graphical abstract is available as Supplementary information.

Utility of the 2018 revised ISN/RPS thresholds for glomerular crescents in childhood-onset lupus nephritis: a Pediatric Nephrology Research Consortium study.

BACKGROUND: The revised 2018 ISN/RPS Classification System for lupus nephritis (LN) includes calculations for both activity index (A.I.) and chronicity index (C.I.). Unchanged were the thresholds of < 25%, 25-50%, and > 50% crescents to distinguish between mild, moderate, and severe activity/chronicity. We aimed to evaluate these thresholds for percent crescents in childhood-onset LN. METHODS: Eighty-six subjects < 21 years of age were enrolled from the Pediatric Glomerulonephritis with Crescents Registry, a retrospective multi-center cohort sponsored by the Pediatric Nephrology Research Consortium. Thresholds of 10%, 25%, and 50% for both cellular/fibrocellular and fibrous crescents were interrogated for primary outcomes of kidney failure, eGFR, and eGFR slope. RESULTS: Median age at time of initial biopsy was 14 years (range 1-21). Median follow-up time was 3 years (range 1-11). Cumulative incidence of kidney failure was 6% at 1 year and 10% at latest follow-up. Median eGFR slope was - 18 mL/1.73 m2/min (IQR - 51 to + 8) at 1 year and - 3 mL/min/1.73 m2/year (IQR - 19 to + 6) at latest follow-up. We found no difference in kidney failure at the proposed < 25% and 25-50% cellular crescents thresholds, and thus added a new provisional threshold of 10% that better predicted outcomes in children. Moreover, use of 10% and 25% thresholds for fibrous crescents showed a fourfold and sevenfold increase in risk of kidney failure. CONCLUSIONS: In children with crescentic LN, use of 10% and 25% thresholds for cellular crescents better reflects disease activity, while these thresholds for fibrous crescents better discriminates kidney disease outcomes. A higher resolution version of the Graphical abstract is available as Supplementary information.

Results of the PROPINE randomized controlled trial: determining the ever-elusive target, the optimal plan for relapses of nephrotic syndrome in children.

Best treatments for initial presentation and relapses in children with nephrotic syndrome (NS) are still to be defined. The PROPINE study, published in this issue of Kidney International, demonstrates for relapse of childhood NS, the non-inferiority of a short taper (over 36 days) after remission with steroids. This study reinforces the need for more well-designed studies and the incorporation of predictive biomarkers, genetic studies, and other details to personalize treatment for each child with idiopathic NS.

Mechanisms and management of edema in pediatric nephrotic syndrome.

Edema is the abnormal accumulation of fluid in the interstitial compartment of tissues within the body. In nephrotic syndrome, edema is often seen in dependent areas such as the legs, but it can progress to cause significant accumulation in other areas leading to pulmonary edema, ascites, and/or anasarca. In this review, we focus on mechanisms and management of edema in children with nephrotic syndrome. We review the common mechanisms of edema, its burden in pediatric patients, and then present our approach and algorithm for management of edema in pediatric patients. The extensive body of experience accumulated over the last 5 decades means that there are many options, and clinicians may choose among these options based on their experience and careful monitoring of responses in individual patients.

Challenges of diagnosing pediatric hypertension using ambulatory blood pressure monitoring.

BACKGROUND: Ambulatory blood pressure monitoring (ABPM) measures mean arterial pressure (MAP) then extrapolates systolic and diastolic blood pressure (BP) values. Pediatric guidelines recommend using calculated systolic and diastolic BP rather than measured MAP for diagnosis of ambulatory hypertension (HTN). The 95th percentile BP that defines ambulatory HTN is higher in some children than thresholds used to define ambulatory HTN in adults. METHODS: This is a retrospective study of patients who underwent 24-h ABPM. The level of agreement in ambulatory HTN diagnosis using MAP vs. systolic/diastolic BP was evaluated using Cohen's kappa coefficient. Similar analysis was done to assess agreement in HTN diagnosis using adult vs. pediatric criteria for males taller than 165 cm. RESULTS: A total of 263 ABPM studies were included. There was good agreement for diagnosis of HTN using MAP or systolic/diastolic BP (k = 0.75; 95% CI: 0.67-0.83). However, there was disagreement between the methods in 12% (n = 31) of subjects. Similarly, there was good agreement (k = 0.70; 95% CI: 0.56-0.85) between pediatric and adult criteria for HTN diagnosis. Nineteen patients were found to be hypertensive (9 using MAP criteria, 10 using adult criteria) who would not have met ambulatory HTN criteria using current pediatric guidelines. CONCLUSIONS: Inclusion of MAP along with systolic and diastolic BP in ABPM analysis alongside using adult criteria for diagnosing HTN in male children ≥ 165 cm may improve accuracy of pediatric HTN diagnosis and reduce false negative rate. Larger studies are needed to assess the clinical validity of these results. Graphical abstract.

The pressure's on: understanding neurocognitive and psychological associations with pediatric hypertension to inform comprehensive care.

The prevalence of hypertension is increasing in pediatric populations. While clinical data and practice guidelines identify the impact of hypertension on organ dysfunction and emphasize the importance for end-organ damage screening, the bidirectional effects of pediatric hypertension on neurocognitive and psychological outcomes are understudied. The objective of this review is to highlight the association between hypertension and cognition, attention, learning, and mental health in children and adolescents. In doing so, this review provides a framework and toolkit to integrate neuropsychology and psychology into the screening and management stages of pediatric hypertension. By recognizing the effects of hypertension on cognition, behavior, and mental health, screenings and interventions can be implemented to proactively and comprehensively improve the health outcomes for children with blood pressure concerns.

Eculizumab exposure in children and young adults: indications, practice patterns, and outcomes-a Pediatric Nephrology Research Consortium study.

BACKGROUND: Eculizumab is approved for the treatment of atypical hemolytic uremic syndrome (aHUS). Its use off-label is frequently reported. The aim of this study was to describe the broader use and outcomes of a cohort of pediatric patients exposed to eculizumab. METHODS: A retrospective, cohort analysis was performed on the clinical and biomarker characteristics of eculizumab-exposed patients < 25 years of age seen across 21 centers of the Pediatric Nephrology Research Consortium. Patients were included if they received at least one dose of eculizumab between 2008 and 2015. Traditional summary statistics were applied to demographic and clinical data. RESULTS: A total of 152 patients were identified, mean age 9.1 (+/-6.8) years. Eculizumab was used "off-label" in 44% of cases. The most common diagnoses were aHUS (47.4%), Shiga toxin-producing Escherichia coli HUS (12%), unspecified thrombotic microangiopathies (9%), and glomerulonephritis (9%). Genetic testing was available for 60% of patients; 20% had gene variants. Dosing regimens were variable. Kidney outcomes tended to vary according to diagnosis. Infectious adverse events were the most common adverse event (33.5%). No cases of meningitis were reported. Nine patients died of noninfectious causes while on therapy. CONCLUSIONS: This multi-center retrospective cohort analysis indicates that a significant number of children and young adults are being exposed to C5 blockade for off-label indications. Dosing schedules were highly variable, limiting outcome conclusions. Attributable adverse events appeared to be low. Cohort mortality (6.6%) was not insignificant. Prospective studies in homogenous disease cohorts are needed to support the role of C5 blockade in kidney outcomes.

Association of infections and venous thromboembolism in hospitalized children with nephrotic syndrome.

BACKGROUND: Nephrotic syndrome (NS) results in hypercoagulability and increased risk of infection. Furthermore, infection increases the risk of venous thromboembolism (VTE). Our objective was to determine the prevalence of infection, VTE, and the associated outcomes among a cohort of hospitalized children with NS. METHODS: All children with NS admitted to 17 pediatric hospitals across North America from 2010 to 2012 were included. Prevalence of infection and VTE was determined. Wilcoxon rank-sum and logistic regression were performed. RESULTS: Seven-hundred thirty hospitalizations occurred among 370 children with NS. One-hundred forty-eight children (40%) had ≥ 1 infection (211 episodes) and 11 (3%) had VTE. Those with VTE had infection more frequently (p = 0.046) and were younger at NS diagnosis (3.0 vs. 4.0 years; p = 0.008). The most common infectious pathogen identified was Streptococcus pneumoniae. The median hospital length of stay for those with infection [10 vs 5 days (p < 0.0001)] or VTE [22 vs 6 days (p < 0.0001)] was longer than those without either complication. Of those with infection, 13% had an intensive care unit (ICU) stay compared with 3.3% of those without infection. Median ICU stay was 4 days in those with VTE compared to 0 days in those without (p < 0.001). By logistic regression, only the number of ICU days was associated with VTE (OR 1.074, 95% CI 1.013-1.138). CONCLUSIONS: Hospitalized children with NS have high rates of infection. Presence of VTE was associated with infection. Both were associated with longer hospitalizations and ICU stays.

Correction to: Recurrence of nephrotic syndrome following kidney transplantation is associated with initial native kidney biopsy findings : A Midwest Pediatric Nephrology Consortium (MWPNC) study.

The original version of this article unfortunately contained a mistake. The subtitle "A Midwest Pediatric Nephrology Consortium (MWPNC) study" was missing. The correct title including subtitle is given above.

Increased Autophagy and Apoptosis in the Kidneys of Intrauterine Growth Restricted Rats.

BACKGROUND: IUGR has been associated with nephron loss and chronic kidney disease (CKD). MATERIALS AND METHODS: We examined autophagy and apoptosis markers in the kidneys of IUGR Sprague Dawley rats induced by maternal low protein diet (LP), comparing them to controls. The autophagy marker LC3B, the pro-apoptotic protein Bax, and the anti-apoptotic protein Bcl-2 were determined by quantitative immunoblotting. Immunohistochemical expressions of LC3B, Bax, and Bcl-2 were evaluated at 4 weeks age. Glomerular counts (by maceration techniques) were performed at 5 weeks. RESULTS: The LP diet offspring were lighter (P < 0.05). In IUGR kidneys, LC3B and Bax were increased at birth (p < 0.05, p < 0.001) and at 4 weeks (p < 0.0142, p < 0.0001), Bcl-2 was decreased at birth (p < 0.05), and there were less glomeruli (p < 0.01) at 5 weeks. CONCLUSIONS: Autophagy and apoptosis may have a role in IUGR associated decreased nephron number in Sprague rats.

HLA-DQA1 and APOL1 as Risk Loci for Childhood-Onset Steroid-Sensitive and Steroid-Resistant Nephrotic Syndrome.

BACKGROUND: Few data exist for the genetic variants underlying the risk for steroid-sensitive nephrotic syndrome (SSNS) in children. The objectives of this study were to evaluate HLA-DQA1 and APOL1 variants as risk factors for SSNS in African American children and use classic HLA antigen types and amino acid inference to refine the HLA-DQA1 association. STUDY DESIGN: Case-control study. SETTING & PARTICIPANTS: African American children with SSNS or steroid-resistant nephrotic syndrome (SRNS) were enrolled from Duke University and centers participating in the Midwest Pediatric Nephrology Consortium. FACTOR: Genetic variants in HLA-DQA1 (C34Y [rs1129740]; F41S [rs1071630]) and APOL1 high-risk alleles. OUTCOMES: SSNS and SRNS. MEASUREMENTS: Direct sequencing for the HLA-DQA1 and APOL1 variants in 115 African American children (65 with SSNS and 50 with SRNS). Imputation of classic HLA alleles and amino acids was done in 363 South Asian children. RESULTS: The 2 HLA-DQA1 variants were significantly associated with SSNS in African American children (C34Y: P=5.7 × 10-11; OR, 3.53; 95% CI, 2.33-5.42; F41S: P=1.2 × 10-13; OR, 4.08; 95% CI, 2.70-6.28), but not with SRNS (C34Y: P=0.6; F41S: P=0.2). APOL1 high-risk variants were not associated with SSNS (P=0.5) but showed significant associations with SRNS (P=1.04 × 10-7; OR, 4.17; 95% CI, 2.23-7.64). HLA-DQA1*0201, HLA-DQB1*0201, and HLA-DRB1*0701 were the classic HLA alleles with the most significant associations with SSNS risk. The most significantly associated amino acid positions were HLA-DQα1 56 and 76 (both P=2.8 × 10-7). Conditional analysis revealed that these variants most likely account for the observed association. LIMITATIONS: Modest sample size and limited statistical power to detect small to moderate effect sizes. Children studied may not be representative of all African American children in the United States. CONCLUSIONS: HLA-DQA1 is a risk locus for SSNS, but not SRNS, in African American children, consistent with its role in SSNS risk in children of European, Asian, and African ancestries. There is little evidence of a significant role for the APOL1 high-risk alleles in childhood SSNS in African American children. Refinement of the HLA-DQA1 association identified the critical classic HLA antigen types and amino acids of the HLA-DQ α1 molecule.

Cost analysis on the use of rituximab and calcineurin inhibitors in children and adolescents with steroid-dependent nephrotic syndrome.

BACKGROUND: Rituximab (RTX) is increasingly being used in place of calcineurin inhibitors (CNI) in pediatric patients with steroid-dependent nephrotic syndrome (SDNS). However, despite its favorable safety profile, its unit cost is prohibitive. We therefore compared the healthcare costs associated with the use of both agents in a retrospective cohort. METHODS: This study was a retrospective analysis of data retrieved from the medical charts and electronic databases of pediatric patients (age range 2-18 years) with SDNS who were treated with either CNI or RTX from January 2008 to December 2012 at Children's Hospital of New Orleans, Louisiana. The minimum follow-up period was 12 months. RESULTS: Of the 18 patients whose medical data were analyzed, ten received RTX and eight were treated with CNI. The annualized healthcare cost for the rituximab group was $197,031 versus $189,857 (all values in US dollars) for the CNI group (p > 0.05). At the 12-month follow-up, more patients in the RTX group were in remission (40 vs. 25%). Duration of freedom from steroid use was longer in the RTX group, while body mass index was higher in the CNI arm (p > 0.05). No significant adverse events occurred in either group. CONCLUSION: The expenditure for the RTX and CNI groups was comparable, but there were fewer clinical encounters in the former group, potentially reducing the burden of healthcare on the patient's family.

Recurrence of nephrotic syndrome following kidney transplantation is associated with initial native kidney biopsy findings.

BACKGROUND AND OBJECTIVES: Steroid-resistant nephrotic syndrome (SRNS) due to focal segmental glomerulosclerosis (FSGS) and minimal change disease (MCD) is a leading cause of end-stage kidney disease in children. Recurrence of primary disease following transplantation is a major cause of allograft loss. The clinical determinants of disease recurrence are not completely known. Our objectives were to determine risk factors for recurrence of FSGS/MCD following kidney transplantation and factors that predict response to immunosuppression following recurrence. METHODS: Multicenter study of pediatric patients with kidney transplants performed for ESKD due to SRNS between 1/2006 and 12/2015. Demographics, clinical course, and biopsy data were collected. Patients with primary-SRNS (PSRNS) were defined as those initially resistant to corticosteroid therapy at diagnosis, and patients with late-SRNS (LSRNS) as those initially responsive to steroids who subsequently developed steroid resistance. We performed logistic regression to determine risk factors associated with nephrotic syndrome (NS) recurrence. RESULTS: We analyzed 158 patients; 64 (41%) had recurrence of NS in their renal allograft. Disease recurrence occurred in 78% of patients with LSRNS compared to 39% of those with PSRNS. Patients with MCD on initial native kidney biopsy had a 76% recurrence rate compared with a 40% recurrence rate in those with FSGS. Multivariable analysis showed that MCD histology (OR; 95% CI 5.6; 1.3-23.7) compared to FSGS predicted disease recurrence. CONCLUSIONS: Pediatric patients with MCD and LSRNS are at higher risk of disease recurrence following kidney transplantation. These findings may be useful for designing studies to test strategies for preventing recurrence.