Epidemiology of childhood interstitial lung disease in France: the RespiRare cohort.

INTRODUCTION: Interstitial lung disease in children (chILD) are rare and mostly severe lung diseases. Very few epidemiological data are available in limited series of patients. The aim of this study was to assess the prevalence and incidence of chILD in France. METHODS: We performed within the RespiRare network a multicentre retrospective observational study in patients with chILD from 2000 to 2022 and a prospective evaluation of chILD's incidence between February 2022 and 2023. RESULTS: chILD was reported in 790 patients in 42 centres. The estimated 2022 prevalence in France was 44 /million children (95% CI 40.76 to 47.46) and the computed incidence was 4.4 /million children (95% CI 3.44 to 5.56). The median age at diagnosis was 3 months with 16.9% of familial forms. Lung biopsy and genetic analyses were performed in 23.4% and 76.9%, respectively. The most frequent chILD aetiologies in the <2 years group were surfactant metabolism disorders (16.3%) and neuroendocrine cell hyperplasia of infancy (11.8%), and in the 2-18 years group diffuse alveolar haemorrhage (12.2%), connective tissue diseases (11.4%), hypersensitivity pneumonitis (8.8%) and sarcoidosis (8.8%). The management included mainly oxygen therapy (52%), corticosteroid pulses (56%), oral corticosteroids (44%), azithromycin (27.2%), enteral nutrition (26.9%), immunosuppressants (20.3%) and hydroxychloroquine (15.9%). The 5-year survival rate was 57.3% for the patients diagnosed before 2 years and 86% between 2 and 18 years. CONCLUSION: This large and systematic epidemiological study confirms a higher incidence and prevalence of chILD than previously described. In order to develop international studies, efforts are still needed to optimise the case collection and to harmonise diagnostic and management practices.

Lumacaftor/Ivacaftor Population Pharmacokinetics in Pediatric Patients with Cystic Fibrosis: A First Step Toward Personalized Therapy.

BACKGROUND: A major breakthrough in cystic fibrosis (CF) therapy was achievedAQ1 with CFTR modulators. The lumacaftor/ivacaftor combination is indicated for the treatment of CF in pediatric patients above 6 years old. Pharmacokinetic (PK) studies of lumacaftor/ivacaftor in these vulnerable pediatric populations are AQ2crucial to optimize treatment protocols. OBJECTIVES AND METHODS: The objectives of this study were to describe the population PK (PPK) of lumacaftor and ivacaftor in children with CF, and to identify factors associated with interindividual variability. The association between drug exposure and clinical response was also investigated. RESULTS: A total of 75 children were included in this PPK study, with 191 concentrations available for each compound and known metabolites (lumacaftor, ivacaftor, ivacaftor-M1, and ivacaftor-M6). PPK analysis was performed using Monolix software. A large interindividual variability was observed. The main sources of interpatient variability identified were patient bodyweight and hepatic function (aspartate aminotransferase). Forced expiratory volume in the first second (FEV1) was statistically associated with the level of exposure to ivacaftor after 48 weeks of treatment. CONCLUSIONS: This study is the first analysis of lumacaftor/ivacaftor PPK in children with CF. These data suggest that dose adjustment is required after identifying variability factors to optimize efficacy. The use of therapeutic drug monitoring as a basis for dose adjustment in children with CF may be useful.

Fetal Lung Volume Appears to Predict Respiratory Morbidity in Congenital Diaphragmatic Hernia.

Congenital diaphragmatic hernia (CDH) is associated with pulmonary hypoplasia and respiratory morbidity. To assess whether respiratory morbidity during the first 2 years of life in infants with left-sided CDH is associated with fetal lung volume (FLV) evaluated by the observed-to-expected FLV ratio (o/e FLV) on antenatal magnetic resonance imaging (MRI). In this retrospective study, o/e FLV measures were collected. Respiratory morbidity in the first 2 years of life was studied according to two endpoints: treatment with inhaled corticosteroids for >3 consecutive months and hospitalization for any acute respiratory disease. The primary outcome was a favorable progression defined by the absence of either endpoint. Forty-seven patients were included. The median o/e FLV was 39% (interquartile range, 33-49). Sixteen (34%) infants were treated with inhaled corticosteroids and 13 (28%) were hospitalized. The most efficient threshold for a favorable outcome was an o/e FLV ≥ 44% with a sensitivity of 57%, specificity of 79%, negative predictive value of 56%, and positive predictive value of 80%. An o/e FLV ≥ 44% was associated with a favorable outcome in 80% of cases. These data suggest that lung volume measurement on fetal MRI may help to identify children at lower respiratory risk and improve information during pregnancy, patient characterization, decisions about treatment strategy and research, and personalized follow-up.

Long-term evolution of neuroendocrine cell hyperplasia of infancy: the FRENCHI findings.

Only few studies report long-term evolution of patients with neuroendocrine cell hyperplasia of infancy (NEHI). We report data from a 54-patient cohort followed up in the French network for rare respiratory diseases (RespiRare). Demographic characteristics and respiratory and nutritional evolution were collected at the time of the patient's last scheduled visit. The mean duration of follow-up was 68 months (5 months to 18 years). Fifteen patients (27.8%) were considered clinically cured. During follow-up, hospitalizations for wheezy exacerbations were reported in 35 patients (55%), and asthma diagnosed in 20 (37%). Chest CT scan improvement was noted in 25/44 (56.8%). Spirometry showed a persistent obstructive syndrome in 8/27 (29.6%). A sleep disorder was rare (2/36, 5.5%). Oxygen weaning occurred in 28 of the 45 patients initially treated (62.2%) and was age-dependent (35.7% under 2 years, 70.5% between 2 and 6 years, and 100% after 7 years). Oxygen duration was linked to a biopsy-proven diagnosis (p = 0.02) and to the use of a nutritional support (p = 0.003). Corticosteroids were largely prescribed at diagnosis, with no evident respiratory or nutritional effect during follow-up. Among 23 patients with an initial failure to thrive, 12 (52.2%) had no weight recovery. Initial enteral feeding (17/54, 31.5%) was stopped at a mean age of 43 months (3 to 120), with no effect on cure and oxygen liberation at the last visit.  Conclusion: Our results show that NEHI has a globally positive, but unequal, improvement over time. Further prospective studies are needed to better clarify the different trajectories of patients with NEHI. What is Known: • Neuroendocrine cell hyperplasia of infancy (NEHI) is an interstitial lung disease whose long-term outcome is considered positive from very few studies including heterogeneous populations. What is New: • The 68-month follow-up of our 54-patient cohort showed respiratory/nutritional symptom persistence in 72.2%, oxygen requiring in 34%, and asthma in 37%. When controlled, radiological or functional improvement was noted in 56.8 and 40.7%. Further prospective studies are needed to better clarify the different trajectories of patients with NEHI.

French national cohort of neuroendocrine cell hyperplasia of infancy (FRENCHI) study: diagnosis and initial management.

Early diagnosis of neuroendocrine cell hyperplasia of infancy (NEHI) is crucial as, conversely to the other causes of intersititial lung disease, corticosteroids are not recommended. Diagnosis is historically based on lung biopsy (NEHI), but in current practice, a clinical and radiological approach is more and more preferred (NEHI syndrome). This national study aimed to address diagnosis and initial management of patients followed up for a NEHI pattern in pediatric centers for rare lung diseases (RespiRare, France). Data on neonatal and familial events, symptoms at diagnosis, explorations performed and results, and therapeutic management were collected by questionnaire. Fifty-four children were included (boys 63%). The mean onset of symptoms was 3.8 ± 2.6 months. The most frequent symptoms at diagnosis were tachypnea (100%), retraction (79.6%), crackles (66.7%), and hypoxemia (59.3%). The mean NEHI clinical score, evocative when ≥ 7/10, was 7.9 ± 1.4 (76% with a score ≥ 7). All chest CT-scans showed ground glass opacities evolving at least the middle lobe and the lingula. Lung biopsy was performed in 38.9% of the cases and was typical of NEHI in only 52.4%, even when the clinical presentation was typical. Initial treatments were oxygen (83.6%) and more curiously intravenous pulses of steroids (83.3%) and azithromycin (70.2%). CONCLUSION: This national cohort of patients underlines diagnosis difficulties of NEHI. A composite clinical and radiological score should help clinicians for limiting the use of anti-inflammatory drugs. WHAT IS KNOWN: •Neuroendocrine cell hyperplasia of infancy (NEHI) is an interstitial lung disease whose diagnosis is essential to limit corticosteroids therapy. WHAT IS NEW: •In this national cohort of 54 patients with a NEHI pattern, diagnosis is mainly based on clinical symptoms and chest CT-scan results. The newly proposed clinical score and, when performed, the lung biopsies are faulted in 25 and 50% of the cases, respectively. •Corticosteroids are widely used. Such results plead for a new composite score to formally diagnose NEHI.

Primary ciliary dyskinesia and fungal infections: Two cases of allergic bronchopulmonary aspergillosis in children.

Primary ciliary dyskinesia (PCD) is a rare inherited disease that affects the movement of the respiratory cilia. The main clinical manifestations are chronic upper and lower respiratory symptoms and recurrent lung infections, particularly bacterial and viral infections. Fungal infections are not usually associated with PCD. Allergic bronchopulmonary aspergillosis (ABPA) is a rare complex immune hypersensitivity reaction to Aspergillus fumigatus reported in patients with asthma and cystic fibrosis. Only three cases of ABPA associated with adult PCD have been described in the literature. Herein, we reported on two cases of ABPA in two boys aged 10 and 13 years with PCD. Both had severe lung disease and chronic Pseudomonas aeruginosa infections. One patient was diagnosed according to the typical clinical features of ABPA, while the other was diagnosed during a scheduled visit with no clinical changes but worsening pulmonary function and radiologic anomalies. The diagnosis of ABPA was confirmed in the two patients who then improved after receiving specific treatment. These two cases were the first to describe the occurrence of ABPA in children with PCD. We recommend that physicians involved in the management of children with PCD be aware of this potential complication.

Esophageal Atresia and Respiratory Morbidity.

BACKGROUND AND OBJECTIVES: Respiratory diseases are common in children with esophageal atresia (EA), leading to increased morbidity and mortality in the first year. The primary study objective was to identify the factors associated with readmissions for respiratory causes in the first year in EA children. METHODS: A population-based study. We included all children born between 2008 and 2016 with available data and analyzed factors at birth and 1 year follow-up. Factors with a P value <.10 in univariate analyses were retained in logistic regression models. RESULTS: Among 1460 patients born with EA, 97 (7%) were deceased before the age of 1 year, and follow-up data were available for 1287 patients, who constituted our study population. EAs were Ladd classification type III or IV in 89%, preterm birth was observed in 38%, and associated malformations were observed in 52%. Collectively, 61% were readmitted after initial discharge in the first year, 31% for a respiratory cause. Among these, respiratory infections occurred in 64%, and 35% received a respiratory treatment. In logistic regression models, factors associated with readmission for a respiratory cause were recurrence of tracheoesophageal fistula, aortopexy, antireflux surgery, and tube feeding; factors associated with respiratory treatment were male sex and laryngeal cleft. CONCLUSIONS: Respiratory morbidity in the first year after EA repair is frequent, accounting for >50% of readmissions. Identifying high risk groups of EA patients (ie, those with chronic aspiration, anomalies of the respiratory tract, and need for tube feeding) may guide follow-up strategies.

A Case of Phage Therapy against Pandrug-Resistant Achromobacter xylosoxidans in a 12-Year-Old Lung-Transplanted Cystic Fibrosis Patient.

Bacteriophages are a promising therapeutic strategy among cystic fibrosis and lung-transplanted patients, considering the high frequency of colonization/infection caused by pandrug-resistant bacteria. However, little clinical data are available regarding the use of phages for infections with Achromobacter xylosoxidans. A 12-year-old lung-transplanted cystic fibrosis patient received two rounds of phage therapy because of persistent lung infection with pandrug-resistant A. xylosoxidans. Clinical tolerance was perfect, but initial bronchoalveolar lavage (BAL) still grew A. xylosoxidans. The patient's respiratory condition slowly improved and oxygen therapy was stopped. Low-grade airway colonization by A. xylosoxidans persisted for months before samples turned negative. No re-colonisation occurred more than two years after phage therapy was performed and imipenem treatment was stopped. Whole genome sequencing indicated that the eight A. xylosoxidans isolates, collected during phage therapy, belonged to four delineated strains, whereby one had a stop mutation in a gene for a phage receptor. The dynamics of lung colonisation were documented by means of strain-specific qPCRs on different BALs. We report the first case of phage therapy for A. xylosoxidans lung infection in a lung-transplanted patient. The dynamics of airway colonization was more complex than deduced from bacterial culture, involving phage susceptible as well as phage resistant strains.

Quality of life was similar in children with congenital diaphragmatic hernia and oesophageal atresia and related to respiratory morbidity.

AIM: To assess quality of life (QoL) in children with congenital diaphragmatic hernia (CDH) and to compare it with oesophageal atresia (OA). METHODS: A cross-sectional study in CDH children (≥7 years) was conducted in Lille University Hospital, France, from January 2013 to April 2014. History, lung function (rest, exercise) and Pediatric Quality of Life Inventory questionnaires (PedsQoL 4.0) were collected. Data of OA children were previously published. RESULTS: Fifty-four CDH patients (male: 53%, median age: 11 years, IQR 9-14) were compared to 54 OA patients (male: 61%, median age: 13 years, IQR: 11-15). CDH children had significantly more frequent history of pneumonia (30% vs 13%), exercise limitation (54% vs 35%) and chest deformity (39% vs 11%); 46% had an obstructive pattern and 66% an abnormal cardiopulmonary exercise test. The median PedsQoL total score in children was 81 (IQR 73-90) in CDH and 81 (IQR 72-91) in OA (P = .8). In CDH, duration of neonatal oxygen therapy, hospitalisation for respiratory disease, exercise limitation, inhaled corticosteroids treatment, chest deformity, abnormal cardiopulmonary exercise test and lower forced expiratory volume in one second were significantly associated with lower QoL scores. CONCLUSION: PedsQoL scores remained satisfactory in CDH children with CDH, with no difference compared to OA. Patients with respiratory morbidity and lung function impairment, who displayed lower scores, should be identified in order to optimise their management in reference centres.

Overview of STING-Associated Vasculopathy with Onset in Infancy (SAVI) Among 21 Patients.

BACKGROUND: Gain-of-function mutations in STING1 underlie a type I interferonopathy termed SAVI (STING-associated vasculopathy with onset in infancy). This severe disease is variably characterized by early-onset systemic inflammation, skin vasculopathy, and interstitial lung disease (ILD). OBJECTIVE: To describe a cohort of patients with SAVI. METHODS: Assessment of clinical, radiological and immunological data from 21 patients (17 families) was carried out. RESULTS: Patients carried heterozygous substitutions in STING1 previously described in SAVI, mainly the p.V155M. Most were symptomatic from infancy, but late onset in adulthood occurred in 1 patient. Systemic inflammation, skin vasculopathy, and ILD were observed in 19, 18, and 21 patients, respectively. Extensive tissue loss occurred in 4 patients. Severity of ILD was highly variable with insidious progression up to end-stage respiratory failure reached at teenage in 6 patients. Lung imaging revealed early fibrotic lesions. Failure to thrive was almost constant, with severe growth failure seen in 4 patients. Seven patients presented polyarthritis, and the phenotype in 1 infant mimicked a combined immunodeficiency. Extended features reminiscent of other interferonopathies were also found, including intracranial calcification, glaucoma and glomerular nephropathy. Increased expression of interferon-stimulated genes and interferon α protein was constant. Autoantibodies were frequently found, in particular rheumatoid factor. Most patients presented with a T-cell defect, with low counts of memory CD8+ cells and impaired T-cell proliferation in response to antigens. Long-term follow-up described in 8 children confirmed the clinical benefit of ruxolitinib in SAVI where the treatment was started early in the disease course, underlying the need for early diagnosis. Tolerance was reasonably good. CONCLUSION: The largest worldwide cohort of SAVI patients yet described, illustrates the core features of the disease and extends the clinical and immunological phenotype to include overlap with other monogenic interferonopathies.

Mutations in COPA lead to abnormal trafficking of STING to the Golgi and interferon signaling.

Heterozygous missense mutations in coatomer protein subunit α, COPA, cause a syndrome overlapping clinically with type I IFN-mediated disease due to gain-of-function in STING, a key adaptor of IFN signaling. Recently, increased levels of IFN-stimulated genes (ISGs) were described in COPA syndrome. However, the link between COPA mutations and IFN signaling is unknown. We observed elevated levels of ISGs and IFN-α in blood of symptomatic COPA patients. In vitro, both overexpression of mutant COPA and silencing of COPA induced STING-dependent IFN signaling. We detected an interaction between COPA and STING, and mutant COPA was associated with an accumulation of ER-resident STING at the Golgi. Given the known role of the coatomer protein complex I, we speculate that loss of COPA function leads to enhanced type I IFN signaling due to a failure of Golgi-to-ER STING retrieval. These data highlight the importance of the ER-Golgi axis in the control of autoinflammation and inform therapeutic strategies in COPA syndrome.

Severe preschool asthmatics have altered cytokine and anti-viral responses during exacerbation.

BACKGROUND: Preschool asthma/recurrent wheeze is a heterogeneous condition. Different clinical phenotypes have been described, including episodic viral wheeze (EVW), severe intermittent wheeze (SIW), and multiple-trigger wheeze (MTW). OBJECTIVE: To compare clinical, viral, and inflammatory/immune profiling at exacerbation between MTW, SIW, and EVW phenotypes. METHODS: Multicenter, prospective, observational cohort (VIRASTHMA-2). Children (1-5 years) with preschool asthma were enrolled during hospitalization for a severe exacerbation. History and anamnestic data, plasma, and nasal samples were collected at exacerbation (T1) and at steady state, 8 weeks later (T2), and sputum samples were collected at T1. RESULTS: A total of 147 children were enrolled, 37 (25%) had SIW, 18 (12.2%) EVW, and 92 (63%) MTW. They were atopic (47%), exposed to mold (22%) and cigarette smoke (50%), and prone to exacerbations (≥2 in the previous year in 70%). At exacerbation, at least one virus was isolated in 94% and rhinovirus in 75%, with no difference between phenotypes. Children with MTW and SIW phenotypes displayed lower plasma concentrations of IFN-γ (P = .002), IL-5 (P = .020), TNF-α (P = .038), IL-10 (P = .002), IFN-ß (P = .036), and CXCL10 (P = .006) and lower levels of IFN-γ (P = .047) in sputum at exacerbation than children with EVW. At T2, they also displayed lower plasma levels of IFN-γ (P = .045) and CXCL10 (P = .013). CONCLUSION: Among preschool asthmatic children, MTW and SIW, prone to exacerbations, display lower systemic levels of Th1, Th2 cytokines, pro- and anti-inflammatory cytokines, and antiviral responses during severe virus-induced exacerbation.

Bronchopulmonary and vascular anomalies are frequent in children with oesophageal atresia.

AIM: Oesophageal atresia is frequently associated with other malformations, and our aim was to use computed tomography (CT) to explore intrathoracic malformations in patients with this condition. METHOD: This was retrospective study of children aged 0-16 with oesophageal atresia who were born in 1996-2013 and followed up at the French reference centre for rare oesophageal diseases at the University of Lille. Computed tomography scans were available for 48 of the 234 patients during follow-up visits, and these were reviewed by a thoracic radiologist. RESULTS: More than two-thirds of the scans were performed to explore persistent respiratory symptoms. We found that six patients had a pulmonary malformations: four lobar agenesis, one right pulmonary aplasia and one congenital cystic adenomatoid malformation. Computed tomography enabled us to diagnose unexpected thoracic malformations in 16 patients: four lobar agenesis, six arteria lusoria, five persistent left superior vena cava and one partial anomalous pulmonary venous return. It also confirmed the diagnoses of suspected malformations in five patients: one congenital cystic adenomatoid malformation, one pulmonary hypoplasia, two right-sided aortic arches and one communicating bronchopulmonary foregut malformation. CONCLUSION: Intrathoracic anomalies were frequently associated with oesophageal atresia, and contrast-enhanced chest CT scans should be performed on patients with persistent respiratory symptoms.

Health-related quality of life in infants and children with interstitial lung disease.

INTRODUCTION: Interstitial lung disease in children (chILD) is a highly heterogeneous group of rare and severe respiratory disorders. The disease by itself, the burden of the treatments (oxygen therapy, corticosteroid pulses, nutritional support) and recurrent hospitalizations may impair the quality of life (QoL) of these children. The aim of the study was to compare the health-related QoL (HR-QoL) in chILD compared to a healthy population and to find out the predictive factors of an altered QoL. METHODS: Patients aged 1 month to 18 years with ILD of known or unknown etiology were prospectively included. Parents and children over 8 years old were asked to fill the PedsQL 4.0 Generic Core Scale ranging from 0 to 100 points. RESULTS: A total of 78 children were recruited in 13 French pediatric centers. Total scores were 11.94 points (P = 0.0003) less for child self-report and 14.08 points ( P < 0.0001) less for parent proxy-report with respect to the healthy population. The clinical factors associated with a lower total score were: extrapulmonary expression of the disease, higher Fan severity score, long-term oxygen therapy, nutritional support, and a number of oral treatments. CONCLUSION: Using a validated quality of life (QoL) scale, we showed that health-related-QoL is significantly impaired in chILD compared with a healthy population. Factors altering QoL score are easy to recognize and could help identify children at a heightened risk of low QoL.