COBRAPed cohort: Do sensitization patterns differentiate children with severe asthma from those with a milder disease?

BACKGROUND: It is unclear whether sensitization patterns differentiate children with severe recurrent wheeze (SRW)/severe asthma (SA) from those with non-severe recurrent wheeze (NSRW)/non-severe asthma (NSA). Our objective was to determine whether sensitization patterns can discriminate between children from the French COBRAPed cohort with NSRW/NSA and those with SRW/SA. METHODS: IgE to 112 components (c-sIgE) (ImmunoCAP® ISAC) were analyzed in 125 preschools (3-6 years) and 170 school-age children (7-12 years). Supervised analyses and clustering methods were applied to identify patterns of sensitization among children with positive c-sIgE. RESULTS: We observed c-sIgE sensitization in 51% of preschool and 75% of school-age children. Sensitization to house dust mite (HDM) components was more frequent among NSRW than SRW (53% vs. 24%, p < .01). Sensitization to non-specific lipid transfer protein (nsLTP) components was more frequent among SA than NSA (16% vs. 4%, p < .01) and associated with an FEV1/FVC < -1.64 z-score. Among sensitized children, seven clusters with varying patterns were identified. The two broader clusters identified in each age group were characterized by "few sensitizations, mainly to HDM." One cluster (n = 4) with "multiple sensitizations, mainly to grass pollen, HDM, PR-10, and nsLTP" was associated with SA in school-age children. CONCLUSIONS: Although children with wheeze/asthma display frequent occurrences and high levels of sensitization, sensitization patterns did not provide strong signals to discriminate children with severe disease from those with milder disease. These results suggest that the severity of wheeze/asthma may depend on both IgE- and non-IgE-mediated mechanisms.

Methionine supplementation for multi-organ dysfunction in MetRS-related pulmonary alveolar proteinosis.

INTRODUCTION: Pulmonary alveolar proteinosis related to mutations in the methionine tRNA synthetase (MARS1) gene is a severe, early-onset disease that results in death before the age of 2 years in one-third of patients. It is associated with a liver disease, growth failure and systemic inflammation. As methionine supplementation in yeast models restored normal enzymatic activity of the synthetase, we studied the tolerance, safety and efficacy of daily oral methionine supplementation in patients with severe and early disease. METHODS: Four patients received methionine supplementation and were followed for respiratory, hepatic, growth and inflammation-related outcomes. Their course was compared to those of historical controls. Reactive oxygen species production by patient monocytes before and after methionine supplementation was also studied. RESULTS: Methionine supplementation was associated with respiratory improvement, clearance of the extracellular lipoproteinaceous material and discontinuation of whole-lung lavage in all patients. The three patients who required oxygen or noninvasive ventilation could be weaned off within 60 days. In addition, liver dysfunction, inflammation and growth delay improved or resolved. At a cellular level, methionine supplementation normalised the production of reactive oxygen species by peripheral monocytes. CONCLUSION: Methionine supplementation was associated with important improvements in children with pulmonary alveolar proteinosis related to mutations in the MARS1 gene. This study paves the way for similar strategies for other tRNA synthetase deficiencies.

Factors Associated with Asthma Severity in Children: Data from the French COBRAPed Cohort.

BACKGROUND: Severe asthma (SA) in children is a complex, heterogeneous disease, associated with a considerable burden. However, factors influencing asthma severity are poorly described and may differ according to age. OBJECTIVE: To determine whether factors associated with asthma severity differ between preschoolers with severe recurrent wheeze (SRW) and school-age children with SA. METHODS: Data from the French multicenter prospective observational cohort of preschool (3-6 years) children with SRW and nonsevere recurrent wheeze (NSRW) and school-age (7-11 years) children with SA and nonsevere asthma (NSA) (Pediatric Cohort of Bronchial Obstruction and Asthma) were analyzed. RESULTS: A total of 131 preschool children (92 SRW and 49 NSRW) and 207 school-age children (92 SA and 115 NSA) were included. In both univariable and multivariable analysis, SRW was associated with second-hand smoke exposure (multivariable analysis: odds ratio [95% CI], 29.8 [3.57-3910]) and exposure to mold/dampness at home (multivariable analysis: odds ratio [95% CI], 4.22 [1.25-18.2]) compared with NSRW. At school-age, history of atopic dermatitis and food allergy was more frequent in children with SA than in those with NSA. Multivariable analysis confirmed that SA was associated with a history of food allergy (odds ratio [95% CI], 5.01 [2.23-11.9]). CONCLUSIONS: Our data suggest that factors influencing asthma severity may differ according to age. In preschool children with SRW, second-hand smoke and exposure to mold are predominant, whereas associated allergic disorders are mainly involved in SA at school-age.

The economic burden of severe asthma in children: a comprehensive study.

OBJECTIVE: The economic burden of severe asthma (SA) in children is poorly described. We aimed to determine the healthcare costs of SA in children for the French national health insurance (NHI). METHODS: Children (6-18 years of age) with physician-confirmed diagnoses of SA or non-SA (NSA) were identified. Direct and indirect expenditures related to asthma and associated co-morbidities in the previous six months were determined, based on a physician-guided parental questionnaire and confirmed by medical records. The costs for the French NHI were assessed per child over a six month period. RESULTS: Data from 74 children, including 48 with SA (22 requiring omalizumab) and 26 with NSA, were analyzed. The global cost of SA was €3,982 per child over a six-month period, including €3,821 direct costs and €161.9 indirect costs. The global cost was €6,716 (4,220) for those requiring omalizumab vs. €1,669 (3,108) for those who did not (p < 0.01). For children with SA, 65% of direct costs were attributed to medication. Among those on omalizumab, such treatment accounted for 93% of medication costs. The global cost was 10 times higher for children with SA than those with NSA (€3,982 (4,422) vs. €363.2 (352.6), p < 0.01), and 20 times higher for children with SA on omalizumab than those with NSA (p < 0.01). CONCLUSION: The economic burden of SA in children for the French NHI is substantial and mainly driven by the most severe children requiring biologics.

Alveolar proteinosis of genetic origins.

Pulmonary alveolar proteinosis (PAP) is a rare form of chronic interstitial lung disease, characterised by the intra-alveolar accumulation of lipoproteinaceous material. Numerous conditions can lead to its development. Whereas the autoimmune type is the main cause in adults, genetic defects account for a large part of cases in infants and children. Even if associated extra-respiratory signs may guide the clinician during diagnostic work-up, next-generation sequencing panels represent an efficient diagnostic tool. Exome sequencing also allowed the discovery of new variants and genes involved in PAP. The aim of this article is to summarise our current knowledge of genetic causes of PAP.

How can we minimise the use of regular oral corticosteroids in asthma?

Options to achieve oral corticosteroid (OCS)-sparing have been triggering increasing interest since the 1970s because of the side-effects of OCSs, and this has now become achievable with biologics. The Société de Pneumologie de Langue Française workshop on OCSs aimed to conduct a comprehensive review of the basics for OCS use in asthma and issue key research questions. Pharmacology and definition of regular use were reviewed by the first working group (WG1). WG2 examined whether regular OCS use is associated with T2 endotype. WG3 reported on the specificities of the paediatric area. Key "research statement proposals" were suggested by WG4. It was found that the benefits of regular OCS use in asthma outside episodes of exacerbations are poorly supported by the existing evidence. However, complete OCS elimination couldn't be achieved in any available studies for all patients and the panel felt that it was too early to conclude that regular OCS use could be declared criminal. Repeated or prolonged need for OCS beyond 1 g·year-1 should indicate the need for referral to secondary/tertiary care. A strategic sequential plan aiming at reducing overall exposure to OCS in severe asthma was then held as a conclusion of the workshop.

Usefulness of bronchoalveolar lavage in a French pediatric cohort with hypersensitivity pneumonitis.

BACKGROUND: Hypersensitivity pneumonitis (HP) is a rare interstitial lung disease in children, and very little data are available on the frequency, diagnosis, and outcomes of HP. In a pediatric cohort with HP, the characteristics of the CD4/CD8 lymphocyte ratio are often described as nonspecific. METHODS: We used the National French Database (RespiRare) to collect data from the last decade on HP. The diagnosis of HP was defined by the presence of a relevant exposure, clinical symptoms, and compatible lung imaging radiology and was usually defined by positive precipitins antibodies. RESULTS: A total of 16 children with a mean age of 10 years (4-13) presented with HP. All children presented with dyspnea on exertion. Diffuse ground-glass opacity was present in all computed tomography (CT) scans. Research guided by a questionnaire and precipitins antibodies against the corresponding antigens showed that patients were positive for contact with birds with or without fungi. Bronchoalveolar lavage (BAL) was performed in 12 children. The total cell counts were elevated in BAL fluid, with a mean value of 36% lymphocytes. The CD4/CD8 lymphocyte ratio was below one for all children. CONCLUSION: BAL in our pediatric cohort with HP had the same characteristics as that of adults with HP. An HP diagnosis must be considered when dyspnea on exertion and diffuse ground-glass opacity are observed. Carrying out BAL and serological tests can help diagnose and avoid lung biopsy.

Asthma and allergic rhinitis risk depends on house dust mite specific IgE levels in PARIS birth cohort children.

BACKGROUND: The natural history of allergic sensitization in childhood, and its impact on allergic disease development, needs to be clarified. This study aims to identify allergic sensitization and morbidity patterns during the first 8 years of life. METHODS: The study was conducted in the on-going population-based prospective Pollution and Asthma Risk: an Infant Study (PARIS) birth cohort. Sensitization profiles were identified by k-means clustering based upon allergen-specific IgE levels measured at 18 months and 8/9 years. Allergic morbidity profiles were identified by latent class analysis based on symptoms, symptom severity, treatments, and lifetime doctor-diagnoses of asthma, allergic rhinitis, and atopic dermatitis and on lower respiratory infections before 2 years. RESULTS: Five sensitization and 5 allergic morbidity patterns were established in 714 children. Children not sensitized or with isolated and low allergen-specific sensitization were grouped together (76.8%). A profile of early and transient sensitization to foods that increased the risk of asthma later in childhood was identified (4.9%). Children strongly sensitized (≥3.5 kUA/L) to house dust mite at 8/9 years (9.0%) had the highest risk of asthma and allergic rhinitis. Finally, timothy grass pollen at 8/9 years sensitization profile (5.3%) was related to respiratory allergic diseases, as was early onset and persistent sensitization profile (4.1%), this latter being also strongly associated with atopic dermatitis. CONCLUSIONS & CLINICAL RELEVANCE: We show that accurate assessment of the risk of allergic disease should rely on earliness and multiplicity of sensitization, involved allergens, and allergen-specific IgE levels, and not considering solely allergic sensitization as a dichotomous variable (allergen-specific IgE ≥0.35 kUA/L), as usually done. This is particularly striking for house dust mite. We are hopeful that, pending further confirmation in other populations, our findings will improve clinical practice as part of an approach to allergic disease prevention.

Quantitative Lipidomics in Pulmonary Alveolar Proteinosis.

Rationale: Pulmonary alveolar proteinosis (PAP) is characterized by filling of the alveolar spaces by lipoprotein-rich material of ill-defined composition, and is caused by molecularly different and often rare diseases that occur from birth to old age.Objectives: To perform a quantitative lipidomic analysis of lipids and the surfactant proteins A, B, and C in lavage fluids from patients with proteinosis of different causes in comparison with healthy control subjects.Methods: During the last two decades, we have collected BAL samples from patients with PAP due to autoantibodies against granulocyte-macrophage colony-stimulating factor; genetic mutations in CSF2RA (colony-stimulating factor 2 receptor α-subunit), MARS (methionyl aminoacyl-tRNA synthetase), FARSB (phenylalanine-tRNA synthetase, ß-subunit), and NPC2 (Niemann-Pick disease type C2); and secondary to myeloid leukemia. Their lipid composition was quantified.Measurements and Main Results: Free cholesterol was largely increased by 60-fold and cholesteryl esters were increased by 24-fold. There was an excessive, more than 130-fold increase in ceramide and other sphingolipids. In particular, the long-chain ceramides d18:1/20:0 and d18:1/24:0 were elevated and likely contributed to the proapoptotic environment observed in PAP. Cellular debris lipids such as phosphatidylethanolamine and phosphatidylserine were only moderately increased, by four- to sevenfold. The surfactant lipid class phosphatidylcholine expanded 17-fold, lysophosphatidylcholine expanded 54-fold, and the surfactant proteins A, B, and C expanded 144-, 4-, and 17-fold, respectively. These changes did not differ among the various diseases that cause PAP.Conclusions: This insight into the alveolar lipidome may provide monitoring tools and lead to new therapeutic strategies for PAP.

Real-life safety of 5-grass pollen tablet in 5-to-9-year-old children with allergic rhinoconjunctivitis.

BACKGROUND: Although 5-grass pollen sublingual immunotherapy has a good safety profile in controlled clinical trials, additional safety information among pediatric patients in a real-world setting would be useful. OBJECTIVE: To further document the safety of 5-grass tablet among children aged 5 to 9 years with allergic rhinoconjunctivitis (ARC). METHODS: This multicenter, observational study included allergy immunotherapy-naïve 5- to 9-year-old children with grass pollen-induced ARC prescribed with 5-grass tablet daily (3-day dose escalation to 300 index of reactivity [IR]). Patients were followed up daily for safety and tolerability over the first 30 treatment days. Adverse events (AEs) and adverse drug reactions (ADRs) were analyzed descriptively. RESULTS: Three hundred seven children (mean age, 7.1 years) were enrolled. Fifty-eight percent were confirmed as polysensitized, and 36% had mild-to-moderate asthma. Of 307 patients, 233 (76%) reported AEs, and 173/307 (56%) reported ADRs, most frequently mild application-site reactions (throat irritation, oral pruritus, oral paresthesia). Sixteen of 307 (5.2%) patients withdrew because of ADRs. In 143 of 173 (83%) patients, ADRs first occurred within 1 week of starting treatment. More than half of the ADRs lasted less than 2 days, and ADRs resolved spontaneously in 161 of 173 (93%) patients. Recurrences of ADRs were reported in 45 of 173 (26%) patients and were also mainly application-site reactions. No notable differences were found in ADRs related to whether patients had asthma at inclusion. Neither epinephrine use nor admission to intensive care unit was reported. CONCLUSION: The safety profile of 5-grass tablet in pediatric ARC patients aged 5 to 9 years was consistent with safety findings in older patients, most ADRs being at the application site and mild to moderate. ClinicalTrials.gov identifier: NCT02295969; EUPAS registration number: 8104.

Unsupervised trajectories of respiratory/allergic symptoms throughout childhood in the PARIS cohort.

BACKGROUND: Natural course and co-occurrence of asthma, eczema, and allergic rhinitis through childhood are still not fully documented. We aim to identify and characterize profiles based on the time course, severity, and apparent triggers of respiratory/allergy symptoms in school-aged children. METHODS: Data on occurrence, severity, and triggers of asthma, rhinitis, and dermatitis symptoms were collected annually during the follow-up of the PARIS birth cohort. Children with similar symptom trajectories until 8-9 years were grouped into profiles using multidimensional (all symptoms considered simultaneously) cluster analysis. Associations between profiles and different health outcomes were analyzed using logistic or linear regression models. RESULTS: Six distinct symptomatic profiles were identified. A profile was defined by persistent dermatitis symptoms, associated with sensitization to food and aeroallergens. Two profiles were characterized by wheezing: one with early transient wheezing and the other with persistent wheezing related to doctor-diagnosed asthma, airway obstruction, and perennial aeroallergen sensitization. Three profiles were characterized by rhinitis symptoms: one non-allergic and two allergic, either with persistent rhinitis symptoms related to allergic multimorbidity and sensitization to perennial aeroallergens, or with late-onset symptoms, related to both pollen and perennial aeroallergens sensitization as well as low lung function. CONCLUSION: This study brings further insights into the developmental profiles of respiratory/allergic outcomes from birth to school age. The identified profiles clearly differed regarding objective features such as diagnosed morbidity, sensitization, or lung function measurements, thus highlighting their biologic and clinical relevance. Allergic rhinitis profiles deserve particular attention, since they were likely to be involved in multimorbidity patterns.

Correction: Wheezing phenotypes and risk factors in early life: The ELFE cohort.

[This corrects the article DOI: 10.1371/journal.pone.0196711.].

Eosinophilic granulomatosis with polyangiitis in children: Data from the French RespiRare® cohort.

OBJECTIVES: To describe the characteristics of pediatric cases of eosinophilic granulomatosis with polyangiitis (EGPA), a systemic necrotizing vasculitis rarely diagnosed in children, retrieved from the French Reference Center for rare pediatric lung diseases and compared with adult cases included in the French Vasculitis Study Group cohort. METHODS: We collected information on pediatric EGPA disease presentation, management, and outcome. Cases met the Lanham criteria and/or American College of Rheumatology classification criteria. RESULTS: Fourteen cases of pediatric EGPA were included, from 1980 to 2012, with a median follow-up of 58.5 months. Median age at diagnosis was 12.3 years. All cases had respiratory involvement. The organ systems most frequently involved were the upper airway (85%), skin (71%), digestive tract (64%), and heart (57%). Neurological and renal involvement were rare. Four of the fourteen children were positive for ANCA (30.7%). During follow-up, three children required intensive care and one child died. The relapse rate was 64%. In comparison with an adult cohort, we found more ENT, heart, and digestive-tract involvement, and fewer neurological manifestations. In children, the delay between asthma onset and diagnosis was shorter, and biopsies showed fewer features of vasculitis. CONCLUSION: This French cohort is the biggest pediatric EGPA series described to date, with a long follow-up period. The findings confirm that pediatric EGPA has specific clinical, radiological, and histological characteristics that differ from adult EGPA. Development of systemic symptoms, and consequently diagnosis, occur with a shorter delay in children, mainly during the eosinophilic phase and leading to a specific presentation.

Mutations in MARS identified in a specific type of pulmonary alveolar proteinosis alter methionyl-tRNA synthetase activity.

Biallelic missense mutations in MARS are responsible for rare but severe cases of pulmonary alveolar proteinosis (PAP) prevalent on the island of La Réunion. MARS encodes cytosolic methionyl-tRNA synthetase (MetRS), an essential translation factor. The multisystemic effects observed in patients with this form of PAP are consistent with a loss-of-function defect in an ubiquitously expressed enzyme. The pathophysiological mechanisms involved in MARS-related PAP are currently unknown. In this work, we analyzed the effect of the PAP-related mutations in MARS on the thermal stability and on the catalytic parameters of the MetRS mutants, relative to wild-type. The effect of these mutations on the structural integrity of the enzyme as a member of the cytosolic multisynthetase complex was also investigated. Our results establish that the PAP-related substitutions in MetRS impact the tRNAMet -aminoacylation reaction especially at the level of methionine recognition, and suggest a direct link between the loss of activity of the enzyme and the pathological disorders in PAP.

Traffic-related Air Pollution, Lung Function, and Host Vulnerability. New Insights from the PARIS Birth Cohort.

RATIONALE: Although the effects of traffic-related air pollution on respiratory exacerbations have been well documented, its impact on lung function in childhood remains unclear. OBJECTIVES: Our aim was to investigate the associations of prenatal, early, and lifetime traffic-related air pollution exposure with lung function at 8-9 years studying possible effect modification by sex, sensitization at 8-9 years, and early lower respiratory tract infections. METHODS: We conducted this study among 788 children from the PARIS (Pollution and Asthma Risk: an Infant Study) birth cohort. Lung function tests were performed during the medical examination at 8-9 years. Traffic-related air pollution exposure during each trimester of pregnancy was estimated using nitrogen oxides background measurements. Postnatal traffic-related air pollution exposure was assessed by a nitrogen oxides air dispersion model at both residential and daycare/school addresses. Associations between lung function and traffic-related air pollution exposure were analyzed by multiple linear regression models. RESULTS: Higher prenatal nitrogen oxides levels, especially during the second trimester of pregnancy, were associated with a lower forced expiratory flow at 25-75% of the forced vital capacity, but there were no significant associations between prenatal nitrogen oxide levels and forced vital capacity, forced expiratory volume during 1 second, or the forced expiratory volume during 1 second/forced vital capacity ratio overall. Postnatal traffic-related air pollution exposure was associated with lower lung function among children with early lower respiratory tract infections or sensitization at 8-9 years, but not in the full cohort. In children with early repeated lower respiratory tract infections, an interquartile increase in lifetime nitrogen oxides exposure was associated with both a lower forced expiratory volume during 1 second (-62.6 ml; 95% confidence interval = -107.0 to -18.1) and forced vital capacity (-55.7 ml; 95% confidence interval = -109.5 to -1.8), but was not associated with the forced expiratory volume during 1 second/forced vital capacity ratio. There was an association between greater early postnatal nitrogen oxide exposure and a lower forced expiratory volume during 1 second/forced vital capacity ratio among sensitized children (-0.65%; 95% confidence interval = -1.25 to -0.05). CONCLUSIONS: This study sheds new light, suggesting associations between postnatal traffic-related air pollution exposure and reduced lung function may be enhanced by early, repeated lower respiratory tract infections or allergic sensitization.

Pulmonary hemosiderosis in children with Down syndrome: a national experience.

BACKGROUND: Pulmonary hemosiderosis is a rare and complex disease in children. A previous study from the French RespiRare® network led to two important findings: 20% of the children presented with both pulmonary hemosiderosis and Down syndrome (DS), and at least one tested autoantibody was found positive in 50%. This study investigates the relationships between pulmonary hemosiderosis and DS. METHODS: Patients younger than 20 years old and followed for pulmonary hemosiderosis were retrieved from the RespiRare® database. Clinical, biological, functional, and radiological findings were collected, and DS and non-DS patients' data were compared. RESULTS: A total of 34 patients (22 girls and 12 boys) were included, among whom nine (26%) presented with DS. The mean age at diagnosis was 4.1 ± 3.27 years old for non-DS and 2.9 ± 3.45 years old for DS patients. DS patients tended to present a more severe form of the disease with an earlier onset, more dyspnoea at diagnosis, more frequent secondary pulmonary hypertension, and an increased risk of fatal evolution. CONCLUSIONS: DS patients have a higher risk of developing pulmonary hemosiderosis, and the disease seems to be more severe in this population. This could be due to the combination of an abnormal lung capillary bed with fragile vessels, a higher susceptibility to autoimmune lesions, and a higher risk of evolution toward pulmonary hypertension. A better screening for pulmonary hemosiderosis and a better prevention of hypoxia in DS paediatric patients may prevent a severe evolution of the disease.

Wheezing phenotypes and risk factors in early life: The ELFE cohort.

OBJECTIVE: Different phenotypes of wheezing have been described to date but not in early life. We aim to describe wheezing phenotypes between the ages of two months and one year, and assess risk factors associated with these wheezing phenotypes in a large birth cohort. METHODS: We studied 18,041 infants from the ELFE (French Longitudinal Study of Children) birth cohort. Parents reported wheezing and respiratory symptoms at two and 12 months, and answered a complete questionnaire (exposure during pregnancy, parental allergy). RESULTS: Children with no symptoms (controls) accounted for 77.2%, 2.1% had had wheezing at two months but no wheezing at one year (intermittent), 2.4% had persistent wheezing, while 18.3% had incident wheezing at one year. Comparing persistent wheezing to controls showed that having one sibling (ORa = 2.19) or 2 siblings (ORa = 2.23) compared to none, nocturnal cough (OR = 5.2), respiratory distress (OR = 4.1) and excess bronchial secretions (OR = 3.47) at two months, reflux in the child at 2 months (OR = 1.55), maternal history of asthma (OR = 1.46) and maternal smoking during pregnancy (OR = 1.57) were significantly associated with persistent wheezing. These same factors, along with cutaneous rash in the child at 2 months (OR = 1.13) and paternal history of asthma (OR = 1.32) were significantly associated with increased odds of incident wheezing. Having one sibling (ORa = 1.9) compared to none, nocturnal cough at 2 months (OR = 1.76) and excess bronchial secretions at 2 months (OR = 1.65) were significantly associated with persistent compared to intermittent wheezing. CONCLUSION: Respiratory symptoms (cough, respiratory distress, and excessive bronchial secretion) were significantly associated with a high risk of persistent wheezing at one year. Smoking exposure during pregnancy was also a risk factor for persistent and incident wheezing.