Results from a nationwide retrospective cohort measure the impact of C3 and soluble C5b-9 levels on kidney outcomes in C3 glomerulopathy.

C3 glomerulopathy (C3G) is a rare complement-mediated disease. Specific treatments are not yet available and factors predictive of kidney survival such as age, kidney function and proteinuria are not specific to C3G. The prognostic value of biomarkers of complement activation, which are pathognomonic of the diseases, remains unknown. In a large cohort of 165 patients from the French National registry, we retrospectively assess the prognostic value of C3, soluble C5b-9 (sC5b-9), C3 nephritic factor, and rare disease-predicting variants in complement genes in predicting clinical outcome of patients. By multivariate analysis age (adult onset), reduced kidney function (defined by estimated glomerular filtration rate under 60ml/min) and presence of rare disease-predicting variants in complement genes predicted risk of progression to kidney failure. Moreover, by multivariate analysis, normal C3/high sC5b-9 levels or low C3/normal sC5b-9 levels remained independently associated with a worse kidney prognosis, with the relative risk 3.7- and 8-times higher, respectively. Subgroup analysis indicated that the complement biomarker profiles independently correlated to kidney prognosis in patients with adult but not pediatric onset. In this subgroup, we showed that profiles of biomarkers C3 and/or sC5b-9 correlated with intra glomerular inflammation and may explain kidney outcomes. In children, only the presence of rare disease-predicting variants correlated with kidney survival. Thus, in an adult population, we propose a three-point C3G prognostic score based on biomarker profiles at risk, estimated glomerular filtration rate at presentation and genetic findings, which may help stratify adult patients into subgroups that require close monitoring and more aggressive therapy.

Cardiac involvement in pediatric hemolytic uremic syndrome.

BACKGROUND: Cardiac involvement is a known but rare complication of pediatric hemolytic uremic syndrome (HUS). We conducted a nationwide observational, retrospective case-control study describing factors associated with the occurrence of myocarditis among HUS patients. METHODS: Cases were defined as hospitalized children affected by any form of HUS with co-existent myocarditis in 8 French Pediatric Intensive Care Units (PICU) between January 2007 and December 2018. Control subjects were children, consecutively admitted with any form of HUS without coexistent myocarditis, at a single PICU in Lyon, France, during the same time period. RESULTS: A total of 20 cases of myocarditis were reported among 8 PICUs, with a mean age of 34.3 ± 31.9 months; 66 controls were identified. There were no differences between the two groups concerning the season and the typical, Shiga toxin-producing Escherichia coli (STEC-HUS), or atypical HUS (aHUS). Maximal leukocyte count was higher in the myocarditis group (29.1 ± 16.3G/L versus 21.0 ± 9.9G/L, p = 0.04). The median time between admission and first cardiac symptoms was of 3 days (range 0-19 days), and 4 patients displayed myocarditis at admission. The fatality rate in the myocarditis group was higher than in the control group (40.0% versus 1.5%, p < 0.001). Thirteen (65%) children from the myocarditis group received platelet transfusion compared to 19 (29%) in the control group (p = 0.03). CONCLUSION: Our study confirms that myocarditis is potentially lethal and identifies higher leukocyte count and platelet transfusion as possible risk factors of myocarditis. A higher resolution version of the Graphical abstract is available as Supplementary information.

Anti-Factor B Antibodies and Acute Postinfectious GN in Children.

BACKGROUND: The pathophysiology of the leading cause of pediatric acute nephritis, acute postinfectious GN, including mechanisms of the pathognomonic transient complement activation, remains uncertain. It shares clinicopathologic features with C3 glomerulopathy, a complement-mediated glomerulopathy that, unlike acute postinfectious GN, has a poor prognosis. METHODS: This retrospective study investigated mechanisms of complement activation in 34 children with acute postinfectious GN and low C3 level at onset. We screened a panel of anticomplement protein autoantibodies, carried out related functional characterization, and compared results with those of 60 children from the National French Registry who had C3 glomerulopathy and persistent hypocomplementemia. RESULTS: All children with acute postinfectious GN had activation of the alternative pathway of the complement system. At onset, autoantibodies targeting factor B (a component of the alternative pathway C3 convertase) were found in a significantly higher proportion of children with the disorder versus children with hypocomplementemic C3 glomerulopathy (31 of 34 [91%] versus 4 of 28 [14%], respectively). In acute postinfectious GN, anti-factor B autoantibodies were transient and correlated with plasma C3 and soluble C5b-9 levels. We demonstrated that anti-factor B antibodies enhance alternative pathway convertase activity in vitro, confirming their pathogenic effect. We also identified crucial antibody binding sites on factor B, including one correlated to disease severity. CONCLUSIONS: These findings elucidate the pathophysiologic mechanisms underlying acute postinfectious GN by identifying anti-factor B autoantibodies as contributing factors in alternative complement pathway activation. At onset of a nephritic syndrome with low C3 level, screening for anti-factor B antibodies might help guide indications for kidney biopsy to avoid misdiagnosed chronic glomerulopathy, such as C3 glomerulopathy, and to help determine therapy.

Kidney function and influence of sunlight exposure in patients with impaired 24-hydroxylation of vitamin D due to CYP24A1 mutations.

Loss-of-function mutations of CYP24A1, the enzyme that converts the major circulating and active forms of vitamin D to inactive metabolites, recently have been implicated in idiopathic infantile hypercalcemia. Patients with biallelic mutations in CYP24A1 present with severe hypercalcemia and nephrocalcinosis in infancy or hypercalciuria, kidney stones, and nephrocalcinosis in adulthood. We describe a cohort of 7 patients (2 adults, 5 children) presenting with severe hypercalcemia who had homozygous or compound heterozygous mutations in CYP24A1. Acute episodes of hypercalcemia in infancy were the first symptom in 6 of 7 patients; in all patients, symptoms included nephrocalcinosis, hypercalciuria, low parathyroid hormone (PTH) levels, and higher than expected 1,25-dihydroxyvitamin D levels. Longitudinal data suggested that in most patients, periods of increased sunlight exposure tended to correlate with decreases in PTH levels and increases in calcemia and calciuria. Follow-up of the 2 adult patients showed reduced glomerular filtration rate and extrarenal manifestations, including calcic corneal deposits and osteoporosis. Cases of severe PTH-independent hypercalcemia associated with hypercalciuria in infants should prompt genetic analysis of CYP24A1. These patients should be monitored carefully throughout life because they may be at increased risk for developing chronic kidney disease.

Early protocol biopsies in pediatric renal transplantation: interest for the adaptation of immunosuppression.

GPB are often performed in PRT to detect subclinical acute rejection or IF/TA. Reducing immunosuppression side effects without increasing rejection is a major concern in PRT. We report the results of GPB in children transplanted with a steroid-sparing protocol adapted to immunological risk. Children under 18 yr who received a renal transplantation between April 1, 2009 and May 31, 2012 were included. Immunosuppression consisted of an antibody induction therapy, tacrolimus, and MMF for all recipients. CSs were administered to children under five yr old, or receiving a second allograft. Twenty-eight children were included, 50% were CSs free. GPB were performed between three and six months. IF/TA was documented in seven biopsies; four of these seven children were CS free. One child, with CSs, presented a borderline rejection, and another child, steroid free, with significant inflammatory interstitial infiltrate, considered as a subclinical rejection, was treated with CSs pulses. The median eGFR was stable (74, 67.5, and 82 mL/min/1.73 m² at, respectively, seven days, three months, and one yr). Patient and graft survival were 100%. These results have to be confirmed in a larger cohort, with long-term follow-up.

Standardization of the management of rheumatoid purpura nephropathy in the West of France. What are the repercussions on the renal sequelae?

Introduction: Rheumatoid purpura is the most common vasculitis in children, and its renal involvement determines the prognosis. To date, no national protocol exists for its management. A protocol was drafted for the French Grand Ouest inter-region in 2011 in order to standardize practices. Objectives: The main objective is to evaluate renal sequelae with a median follow-up of 2 years since the implementation of this protocol. The secondary objectives are to evaluate the different therapeutic and diagnostic management. Method: Inclusion of all children from 2006 to 2018 with nephropathy due to rheumatoid purpura followed in the university hospitals of Rennes, Nantes, Tours, Angers and Brest. Results: 169 patients were included, of whom 104 were treated accroding to protocol and 65 differently. Sequels at 2-year follow-up concerned 27.0% of patients with no significant difference according to whether or not the protocol was followed. A significant decrease of 26.1% in the number of renal biopsies was observed in the group that followed the protocol. The latter was performed with a median delay of less than 30 days. Conclusion: The protocol allowed a standardization of practices without deleterious consequences at 2 years of follow-up and a decrease in renal biopsy punctures. It is in agreement with the recommendations of KDIGO (Kidney Disease Improving Global Outcomes) and European experts. On the other hand, in view of recent studies and the physiopathology, immunosuppressive drugs other than corticosteroids could be introduced earlier in severe forms.

Introduction: Le purpura rhumatoïde est la vascularite la plus fréquente chez l'enfant, dont l'atteinte rénale détermine le pronostic. Aucun protocole national n'existe à ce jour concernant sa prise en charge. Un protocole a été rédigé sur le Grand Ouest de la France en 2011 afin d'uniformiser les pratiques. Objectifs: L'objectif principal est d'évaluer les séquelles rénales avec une médiane de suivi de deux ans depuis la mise en place de ce protocole. Les objectifs secondaires sont d'évaluer les différentes prises en charge thérapeutiques et diagnostiques. Méthodes: Nous avons inclus tous les enfants de 2006 à 2018 ayant présenté une néphropathie due à un purpura rhumatoïde suivis dans les CHU de Rennes, Nantes, Tours, Angers et Brest. Résultats: Au total, 169 patients ont été inclus, dont 104 respectant le protocole et 65 hors protocole. Les séquelles à deux ans de suivi concernent 27 % des patients sans différence significative selon l'application ou non du protocole. Une diminution significative de 26,1 % des ponctions biopsies rénales est observée dans le groupe respectant le protocole. Cette dernière est réalisée avec un délai médian inférieur à 30 jours. Conclusion: Le protocole réalisé par le Grand Ouest a permis une uniformisation des pratiques sans conséquences délétères à deux ans de suivi et une diminution des ponctions biopsies rénales. Il est en accord avec les recommandations du KDIGO (Kidney Disease Improving Global Outcomes) et des experts européens. En revanche, au vu des études récentes et de la physiopathologie, les immunosuppresseurs hors corticothérapies pourraient être intégrés plus précocement dans les formes sévères.

Rare cause of life-threatening hypercalcemia in an infant: a case report. / Cause rare d'hypercalcémie gravissime chez l'enfant : cas clinique

Background: 25-Hydroxyvitamin D 24-hydroxylase (CYP24A1) deficiency is a rare cause of autosomal recessive infantile hypercalcemia due to vitamine D hypersensitivity. Case presentation: We report the case of a 2-year-old boy who presented with severe hypercalcemia-hypercalciuria and a bilateral nephrocalcinosis. Laboratory investigations detected a collapsed parathormone and a highly elevated 1α,25-dihydroxycholecalciferol along with an increased phosphate excretion (hypophosphatemia and hyperphosphaturia). An adapted management with two courses of palmidronic acid and an eviction of vitamin D and calcium allowed to stabilize him. A homozygous p.Leu409Ser pathogenic variant on CYP24A1 gene resulting in a collapsed 25-Hydroxyvitamin D24-hydroxylase activity was found. A normal development is possible with a meticulous clinical, biological and nutritional management and monitoring. Conclusions: Vitamin D hypersensitivity is challenging during childhood, especially due to the need to avoid vitamin D while requiring a close nutritional monitoring to maintain a normal growth. Biomarkers such as vitamin D metabolite ratio and 24,25(OH)2D3 along with ionized calcium and nutritional management can contribute to properly follow patients with vitamin D hypersensitivity.

Contexte: Le déficit en 25-hydroxyvitamine D 24-hydroxylase (CYP24A1) est une cause rare d'hypercalcémie infantile autosomique récessive due à une hypersensibilité à la vitamine D. Présentation du cas: Nous rapportons le cas d'un garçon de 2 ans qui a présenté une hypercalcémie-hypercalciurie sévère et une néphrocalcinose bilatérale. Les examens de laboratoire ont détecté une parathormone effondrée et un 1α,25-dihydroxycholécalciférol très élevé ainsi qu'une excrétion accrue de phosphate (hypophosphatémie et hyperphosphaturie). Une prise en charge adaptée avec deux cures d'acide palmidronique et une éviction de la vitamine D et du calcium a permis de le stabiliser. Un variant pathogène homozygote p.Leu409Ser sur le gène CYP24A1 entraînant un effondrement de l'activité de la 25-hydroxyvitamine D24-hydroxylase a été retrouvé. Un développement normal est possible avec une prise en charge et un suivi clinique, biologique et nutritionnel méticuleux. Conclusions: L'hypersensibilité à la vitamine D est un défi pendant l'enfance, notamment en raison de la nécessité d'éviter la vitamine D tout en exigeant un suivi nutritionnel étroit pour maintenir une croissance normale. Les biomarqueurs tels que le rapport des métabolites de la vitamine D et la 24,25(OH)2D3, ainsi que le calcium ionisé et la gestion nutritionnelle peuvent contribuer à un suivi adéquat des patients souffrant d'hypersensibilité à la vitamine D.

Clinical course and cost assessment of infants with a first episode of acute bronchiolitis presenting to the emergency department: Data from the GUERANDE clinical trial.

INTRODUCTION: Bronchiolitis is the leading cause of hospitalization for infants but its economic burden is not well documented. Our objective was to describe the clinical evolution and to assess the 1-month cost of a first episode of acute bronchiolitis presenting to the emergency department (ED). METHODS: Our study was an epidemiologic analysis and a cost study of the cohort drawn from the clinical trial GUERANDE, conducted in 24 French pediatric EDs. Infants of 6 weeks to 12 months of age presenting at pediatric EDs with a first episode of bronchiolitis were eligible. The costs considered were collected from a societal viewpoint, according to the recommendations of the French National Health Authority. RESULTS: A total of 777 infants were included with a median age of 4 months. A total of 57% were hospitalized during the month following the first consultation in the ED, including 28 (3.6%) in an intensive care unit. The mean length of stay was 4.2 days (SD = 3.7). The average time to relief of all symptoms was 13 days (SD = 7). Average total cost per patient was €1919 (95% confidence interval: 1756-2138) from a societal perspective, mostly due to hospitalization cost. The estimated annual cost of bronchiolitis in infants was evaluated to be between €160 and €273 million in France. DISCUSSION: Bronchiolitis represent a high cost for the health care system and broadly for society, with hospitalizations costs being the main cost driver. Thus significant investments should be made to develop innovative therapies, to reduce the number of hospitalizations and length of stay.

Evaluation of an oral analgesia protocol for upper-limb fracture reduction in the paediatric emergency department: Prospective study of 101 patients.

BACKGROUND: Upper limb injuries are common in children. When required, closed fracture reduction can be performed in the emergency department without general anaesthesia but causes pain. The primary objective of this study was to assess an oral analgesia protocol for fracture reduction without general anaesthesia. The secondary objectives were to look for associations linking pain intensity to age, sex, and waiting time and to determine the frequency of secondary displacement requiring closed reduction or internal fixation under general anaesthesia at the 1-week follow-up visit. HYPOTHESIS: An oral analgesia protocol combining a loading dose of morphine with other medications would provide sufficient pain control to obviate the need for general anaesthesia. MATERIAL AND METHODS: A prospective observational single-centre study was conducted over a 15-month period (July 2017-October 2018) in consecutive patients younger than 16 years who required reduction of a displaced upper-limb fracture. All patients received the same oral combination of paracetamol (15mg/kg), ibuprofen (7.5-10mg/kg), and a loading morphine dose (0.5mg/kg, up to 20mg) 1hour before the procedure. Patients given morphine more than 2hours before the procedure and those with persistent pain were given an additional morphine dose (0.2mg/kg, up to 10mg). An equimolar mixture of oxygen and nitrous oxide was administered during reduction. An appropriate scale was used to measure pain intensity before, during, and 15minutes after the procedure. Cases of secondary displacement requiring further reduction or internal fixation under general anaesthesia at the 1-week follow-up visit were recorded. RESULTS: The 101 study patients (73 male and 28 female) had a mean age of 9.4 years (range, 2-15 years). Mean pain scores were 5.0±2.6 at admission and 2.1±2.3, 2.6±3.3, and 1.3±2.2 before, during, and after reduction, respectively. Pain intensity during reduction was significantly associated with age. The analgesia was deemed satisfactory by 94 patients and 90 parents. General anaesthesia for further treatment was required in 10 (9.9%) patients, either on the day after the initial treatment, due to inadequate reduction (n=8), or at the 1-week visit, due to secondary displacement (n=2). DISCUSSION: Oral morphine in a sufficient dosage given in combination with other medications was effective and well tolerated when used to control pain during upper-limb fracture reduction. Pain intensity was not significantly associated with sex. In contrast, pain was significantly more severe in the patients older than 10 years of age. The proportions of patients requiring further reduction or internal fixation were consistent with previously published data. Most patients and parents were satisfied with the analgesia protocol. CONCLUSION: A multimodal oral analgesia protocol provides sufficient pain relief to allow closed reduction of upper-limb fractures in children at the emergency department. This management strategy provided high satisfaction rates in both the patients and their parents. LEVEL OF EVIDENCE: II, prospective observational study.

Prevalence of Novel MAGED2 Mutations in Antenatal Bartter Syndrome.

BACKGROUND AND OBJECTIVES: Mutations in the MAGED2 gene, located on the X chromosome, have been recently detected in males with a transient form of antenatal Bartter syndrome or with idiopathic polyhydramnios. The aim of this study is to analyze the proportion of the population with mutations in this gene in a French cohort of patients with antenatal Bartter syndrome. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The French cohort of patients with antenatal Bartter syndrome encompasses 171 families. Mutations in genes responsible for types 1-4 have been detected in 75% of cases. In patients without identified genetic cause (n=42), transient antenatal Bartter syndrome was reported in 12 cases. We analyzed the MAGED2 gene in the entire cohort of negative cases by Sanger sequencing and retrospectively collected clinical data regarding pregnancy as well as the postnatal outcome for positive cases. RESULTS: We detected mutations in MAGED2 in 17 patients, including the 12 with transient antenatal Bartter syndrome, from 16 families. Fifteen different mutations were detected (one whole deletion, three frameshift, three splicing, three nonsense, two inframe deletions, and three missense); 13 of these mutations had not been previously described. Interestingly, two patients are females; in one of these patients our data are consistent with selective inactivation of chromosome X explaining the severity. The phenotypic presentation in our patients was variable and less severe than that of the originally described cases. CONCLUSIONS: MAGED2 mutations explained 9% of cases of antenatal Bartter syndrome in a French cohort, and accounted for 38% of patients without other characterized mutations and for 44% of male probands of negative cases. Our study confirmed previously published data and showed that females can be affected. As a result, this gene must be included in the screening of the most severe clinical form of Bartter syndrome.

Effect of Nebulized Hypertonic Saline Treatment in Emergency Departments on the Hospitalization Rate for Acute Bronchiolitis: A Randomized Clinical Trial.

Importance: Acute bronchiolitis is the leading cause of hospitalization among infants. Previous studies, underpowered to examine hospital admission, have found a limited benefit of nebulized hypertonic saline (HS) treatment in the pediatric emergency department (ED). Objective: To examine whether HS nebulization treatment would decrease the hospital admission rate among infants with a first episode of acute bronchiolitis. Design, Setting, and Participants: The Efficacy of 3% Hypertonic Saline in Acute Viral Bronchiolitis (GUERANDE) study was a multicenter, double-blind randomized clinical trial on 2 parallel groups conducted during 2 bronchiolitis seasons (October through March) from October 15, 2012, through April 15, 2014, at 24 French pediatric EDs. Among the 2445 infants (6 weeks to 12 months of age) assessed for inclusion, 777 with a first episode of acute bronchiolitis with respiratory distress and no chronic medical condition were included. Interventions: Two 20-minute nebulization treatments of 4 mL of HS, 3%, or 4 mL of normal saline (NS), 0.9%, given 20 minutes apart. Main Outcomes and Measures: Hospital admission rate in the 24 hours after enrollment. Results: Of the 777 infants included in the study (median age, 3 months; interquartile range, 2-5 months; 468 [60.2%] male), 385 (49.5%) were randomized to the HS group and 387 (49.8%) to the NS group (5 patients did not receive treatment). By 24 hours, 185 of 385 infants (48.1%) in the HS group were admitted compared with 202 of 387 infants (52.2%) in the NS group. The risk difference for hospitalizations was not significant according to the mixed-effects regression model (adjusted risk difference, -3.2%; 95% CI, -8.7% to 2.2%; P = .25). The mean (SD) Respiratory Distress Assessment Instrument score improvement was greater in the HS group (-3.1 [3.2]) than in the NS group (-2.4 [3.3]) (adjusted difference, -0.7; 95% CI, -1.2 to -0.2; P = .006) and similarly for the Respiratory Assessment Change Score. Mild adverse events, such as worsening of cough, occurred more frequently among children in the HS group (35 of 392 [8.9%]) than among those in the NS group (15 of 384 [3.9%]) (risk difference, 5.0%; 95% CI, 1.6%-8.4%; P = .005), with no serious adverse events. Conclusions and Relevance: Nebulized HS treatment did not significantly reduce the rate of hospital admissions among infants with a first episode of acute moderate to severe bronchiolitis who were admitted to the pediatric ED relative to NS, but mild adverse events were more frequent in the HS group. Trial Registration: clinicaltrials.gov Identifier: NCT01777347.