Interstitial lung diseases in children

Interstitial lung disease (ILD) in children (chILD) is a heterogeneous group of rare respiratory disorders that are mostly chronic and associated with high morbidity and mortality. The pathogenesis of the various chILD is complex and the diseases share common features of inflammatory and fibrotic changes of the lung parenchyma that impair gas exchanges. The etiologies of chILD are numerous. In this review, we chose to classify them as ILD related to exposure/environment insults, ILD related to systemic and immunological diseases, ILD related to primary lung parenchyma dysfunctions and ILD specific to infancy. A growing part of the etiologic spectrum of chILD is being attributed to molecular defects. Currently, the main genetic mutations associated with chILD are identified in the surfactant genes SFTPA1, SFTPA2, SFTPB, SFTPC, ABCA3 and NKX2-1. Other genetic contributors include mutations in MARS, CSF2RA and CSF2RB in pulmonary alveolar proteinosis, and mutations in TMEM173 and COPA in specific auto-inflammatory forms of chILD. However, only few genotype-phenotype correlations could be identified so far. Herein, information is provided about the clinical presentation and the diagnosis approach of chILD. Despite improvements in patient management, the therapeutic strategies are still relying mostly on corticosteroids although specific therapies are emerging. Larger longitudinal cohorts of patients are being gathered through ongoing international collaborations to improve disease knowledge and targeted therapies. Thus, it is expected that children with ILD will be able to reach the adulthood transition in a better condition.

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.

Use of ruxolitinib in COPA syndrome manifesting as life-threatening alveolar haemorrhage

COPA (coatomer subunit α) syndrome is a newly recognised cause of interstitial lung disease in children and adults, frequently associated with arthritis and renal dysfunction. We report a 11-year-old girl with disease limited to major pulmonary haemosiderosis manifesting at the age of 2 years, due to a heterozygous p.(Arg233His) mutation in COPA Her interferon (IFN) signature was elevated (10.312 and 12.429, healthy <2.466), as was the level of serum IFNα (211 fg/mL, healthy <10 fg/mL). STAT1 phosphorylation in T lymphocytes and monocytes was increased as compared with healthy controls. Based on these results she was treated with the JAK1/2 inhibitor ruxolitinib, which resulted in reduction in IFN signalling and appeared to be associated with partial though incomplete decrease in the severity of her pulmonary disease. Patients with alveolar haemorrhage of unknown origin should be considered for COPA screening. Functional tests can help to personalise patient therapy.

Pilot experience of multidisciplinary team discussion dedicated to inherited pulmonary fibrosis

Background

Genetic testing is proposed for suspected cases of monogenic pulmonary fibrosis, but clinicians and patients need specific information and recommendation about the related diagnosis and management issues. Because multidisciplinary discussion (MDD) has been shown to improve accuracy of interstitial lung disease (ILD) diagnosis, we evaluated the feasibility of a genetic MDD (geneMDD) dedicated to the indication for and interpretation of genetic testing. The geneMDD group met monthly and included pediatric and adult lung specialists with ILD expertise, molecular and clinical geneticists, and one radiologist. Hematologists, rheumatologists, dermatologists, hepatologists, and pathologists were also invited to attend.

Results

Since 2016, physicians from 34 different centers in 7 countries have participated in the geneMDD. The medical files of 95 patients (53 males) have been discussed. The median age of patients was 43 years [range 0–77], 10 were ≤ 15 years old, and 6 were deceased at the time of the discussion. Among 85 analyses available, the geneMDD considered the rare gene variants pathogenic for 61: 37 variants in telomere-related genes, 23 variants in surfactant-related genes and 1 variant in MARS. Genetic counseling was offered for relatives of these patients. The geneMDD therapeutic proposals were as follows: antifibrotic drugs (n = 25), steroids or immunomodulatory therapy (n = 18), organ transplantation (n = 21), watch and wait (n = 21), or best supportive care (n = 4).

Conclusion

Our experience shows that a dedicated geneMDD is feasible regardless of a patient’s age and provides a unique opportunity to adapt patient management and therapy in this very rare condition.

Adapting implementation strategies: a case study of how to support implementation of healthy canteen policies

OBJECTIVES

Although evidence-based interventions (EBIs) and effective strategies to implement them exist, they cannot be used by policy makers and practitioners if they do not align with end users' needs. As such, adaptations to EBIs and implementation approaches are likely to occur to increase 'fit' with end users' capacity. This article describes an approach undertaken by a population health service delivery unit in one Australian state to develop an adapted implementation strategy to support the implementation of the mandatory healthy canteen policy (EBI) to all schools located in the service delivery region.

STUDY DESIGN

This is a case study of adapting an intervention to improve implementation of the healthy canteen policy.

METHODS AND RESULTS

This is a six-step pragmatic, empirically driven approach. The steps include (i) adapt, where appropriate, the EBI to facilitate implementation; (ii) identify end users' capacity for implementation; (iii) identify opportunities to adapt the implementation interventions while preserving meaningful intervention impact; (iv) undertake program adaptation; (v) develop training and resources to support delivery of implementation strategies and; (vi) evaluate the adapted intervention. This article describes the application of these steps by the authors to develop an adapted support strategy consistent with end users' needs.

CONCLUSIONS

This study provides some guidance on how to adapt implementation support approaches particularly when EBIs cannot be adapted. Future empirical research providing guidance on making practical adaptation decisions are needed.

Pulmonary Fibrosis in Children

: Pulmonary fibrosis (PF) is a very rare condition in children, which may be observed in specific forms of interstitial lung disease. None of the clinical, radiological, or histological descriptions used for PF diagnosis in adult patients, especially in situations of idiopathic PF, can apply to pediatric situations. This observation supports the view that PF expression may differ with age and, most likely, may cover distinct entities. The present review aims at summarizing the current understanding of PF pathophysiology in children and identifying suitable diagnostic criteria.

Bi-allelic missense ABCA3 mutations in a patient with childhood ILD who reached adulthood

The adenosine triphosphate (ATP)-binding cassette subfamily A member 3 (ABCA3) is a transmembrane glycoprotein that uses energy of ATP hydrolysis to transport phospholipids into the lamellar bodies of type 2 alveolar epithelial cells (AEC) and regulates lung surfactant homeostasis. More than 200 mutations have already been described in ABCA3, located on chromosome 16 [1, 2]. Patients present with a great heterogeneity of phenotypes, from lethal neonatal respiratory distress syndrome (RDS) to childhood and rarely adult interstitial lung disease (ILD) [3, 4]. ABCA3 mutations-related lung disease inheritance is autosomal recessive, as it requires two disease-causing (bi-allelic) mutations, one from each parent.

Children with ABCA3 mutations may survive beyond infancy and reach adulthood. Genetic mechanisms should always be examined in adult patients with childhood onset ILD and molecular analysis should be performed accordingly in specialised referral centres.http://bit.ly/2LzMNOE

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.

A Nonsmoker Man in His 40s With a Diagnosis of Genetic-Related Idiopathic Pulmonary Fibrosis (Surfactant-Protein C Gene Mutation)

A nonsmoker man in his 40s underwent bilateral lung transplantation with a referral diagnosis of genetic-related idiopathic pulmonary fibrosis (IPF). The patient had no medical history in childhood and early adulthood, nor was there a family history of IPF. His nonsmoker father presented with lung cancer at 59 years of age. The patient was a professional brass instrument player; he had started playing at 9 years of age, and he was recently playing 3 to 4 h per day. He had a 7-year clinical history of chronic cough and shortness of breath. Bilateral fine crackles were present at clinical examination. There was no digital clubbing. Data had been collected since 2015: no clinical or immunologic signs of connective tissue disease were evident, including autoantibodies for myositis or anti-synthetase syndrome. Chest radiograph showed diffuse interstitial lung disease. Results of pulmonary function tests yielded a restrictive pattern with decreased FVC and decreased total lung capacity (69% and 47% of predicted, respectively). The FEV₁/FVC ratio was 86%, and carbon monoxide transfer coefficient was 36% of predicted. BAL cellular analysis consisted of macrophages (66%), lymphocytes (19%; CD4⁺/CD8⁺ ratio, 0.16), neutrophils (10%), and eosinophils (5%).

A pilot randomized controlled trial examining the impact of a sleep intervention targeting home routines on young children's (3-6 years) physical activity

BACKGROUND

Given evidence suggesting that sleep impacts on metabolic processes, interventions targeting sleep may improve child physical activity (PA).

OBJECTIVES

To describe the potential effect of an intervention to increase sleep on young children's (3-6 years) moderate to vigorous PA (MVPA) and total PA. To determine adherence to the intervention, impact on sleep duration as well as feasibility, uptake and acceptability was also assessed.

METHODS

Pilot randomized controlled trial with 76 parent-child dyads randomly allocated to an intervention (n = 38) or control group (n = 38). Parents in the intervention group received a 3-month theory-informed intervention consisting of an online video, a telephone call and two text messages. Child PA was assessed using accelerometers at baseline and approximately 3 months. Parents also completed a sleep log and a telephone interview.

RESULTS

The consent rate was 41% (76/186). Estimated effect size for the intervention relative to control was 10.8 min/day for MVPA, 2.7 min/day for PA and 0.9 h for sleep. Sixteen (44%) parents accessed the video, and 18 (50%) received the telephone call. Over 40% of parents found the video and telephone call useful/very useful.

CONCLUSIONS

This study reports promising effects that an intervention targeting sleep may improve child MVPA and sleep duration. Some modifications to data collection methods and intervention delivery are needed.

Paediatric sarcoidosis

Paediatric sarcoidosis is an extremely rare disease characterized by a granulomatous inflammation. The estimated incidence is 0.6-1.02/100,000 children, but in the absence of international registers, the disease is probably under-reported. Its pathophysiologic basis is not clearly understood but the current hypothesis is a combination of a genetic predisposition and an environmental exposure that could be either organic or mineral. Contrary to adult forms of the disease, general symptoms are often at the forefront at diagnosis. In its most frequent form, paediatric sarcoidosis is a multi-organ disorder affecting preferentially the lungs, the lymphatic system and the liver, but all organs can be affected. This review aims to provide an overview of current knowledge on sarcoidosis in children, providing a summary of the data available from cohort studies on the presentation, the management and the evolution of the disease in this specific population.

MUC5B Promoter Variant and Rheumatoid Arthritis with Interstitial Lung Disease

BACKGROUND

Given the phenotypic similarities between rheumatoid arthritis (RA)-associated interstitial lung disease (ILD) (hereafter, RA-ILD) and idiopathic pulmonary fibrosis, we hypothesized that the strongest risk factor for the development of idiopathic pulmonary fibrosis, the gain-of-function MUC5B promoter variant rs35705950, would also contribute to the risk of ILD among patients with RA.

METHODS

Using a discovery population and multiple validation populations, we tested the association of the MUC5B promoter variant rs35705950 in 620 patients with RA-ILD, 614 patients with RA without ILD, and 5448 unaffected controls.

RESULTS

Analysis of the discovery population revealed an association of the minor allele of the MUC5B promoter variant with RA-ILD when patients with RA-ILD were compared with unaffected controls (adjusted odds ratio, 3.8; 95% confidence interval [CI], 2.8 to 5.2; P=9.7×10^-17). The MUC5B promoter variant was also significantly overrepresented among patients with RA-ILD, as compared with unaffected controls, in an analysis of the multiethnic case series (adjusted odds ratio, 5.5; 95% CI, 4.2 to 7.3; P=4.7×10^-35) and in a combined analysis of the discovery population and the multiethnic case series (adjusted odds ratio, 4.7; 95% CI, 3.9 to 5.8; P=1.3×10^-49). In addition, the MUC5B promoter variant was associated with an increased risk of ILD among patients with RA (adjusted odds ratio in combined analysis, 3.1; 95% CI, 1.8 to 5.4; P=7.4×10^-5), particularly among those with evidence of usual interstitial pneumonia on high-resolution computed tomography (adjusted odds ratio in combined analysis, 6.1; 95% CI, 2.9 to 13.1; P=2.5×10^-6). However, no significant association with the MUC5B promoter variant was observed for the diagnosis of RA alone.

CONCLUSIONS

We found that the MUC5B promoter variant was associated with RA-ILD and more specifically associated with evidence of usual interstitial pneumonia on imaging. (Funded by Société Française de Rhumatologie and others.).

Chronic interstitial lung diseases in children: diagnosis approaches

Introduction: Children interstitial lung disease (chILD) is a heterogeneous group of rare respiratory disorders characterized by inflammatory and fibrotic changes of the lung parenchyma. They include ILD related to exposure/environment insults, ILD related to systemic diseases processes, ILD related to primary lung parenchyma dysfunctions and ILD specific to infancy. Areas covered: This review provides an update on chILD pathophysiology and diagnosis approaches in immunocompetent children. It includes current information on genetic causes. Expert commentary: ChILD covers a large spectrum of entities with heterogeneous disease expression. Various classifications have been reported, but none of them seems completely satisfactory. Recently, progress in molecular genetics has allowed identifying some genetic contributors, with, so far, a lack of correlations between gene disorders and disease expression. Despite improvements in patient management, chILD prognosis is still burdened by significant morbidity and mortality. Ongoing international collaborations will allow gathering larger longitudinal cohorts of patients to improve disease knowledge and personalized care. The overall goal is to help the children with ILD to reach the adulthood transition in a better condition, and to structure genetic counseling for their family.

Anesthetic management of parturients with Arnold Chiari malformation-I: a multicenter retrospective study

BACKGROUND

Consensus regarding the safest mode of delivery and anesthetic management for parturients with Arnold Chiari malformation-I (ACM-I) remains controversial. This study assessed their anesthetic management and reported anesthetic complications during hospitalization for delivery.

METHODS

This was a multicenter, retrospective, cohort study of patients with ACM-I undergoing vaginal or cesarean delivery. Data were obtained from the electronic databases of four United States academic institutions using International Classification of Diseases (ICD) codes from 2007-2017 at three sites and 2004-2017 at one site. The primary outcome was anesthetic complications.

RESULTS

Data were analyzed for 185 deliveries in 148 patients. Diagnosis of ACM-I was made prior to delivery in 147 (80%) cases. Pre-delivery neurosurgical consultation for management of ACM-I was performed in 53 (36%) patients. Pre-existing symptoms were recorded for 89 (48%) of the deliveries. Vaginal deliveries occurred in 80 (43%) cases, and 62 women (78%) received neuraxial labor analgesia. Cesarean delivery was performed in 105 (57%) cases, of which 70 women (67%) had neuraxial anesthesia and 34 (32%) received general anesthesia. Post-dural puncture headache was reported in three (2%) patients who had neuraxial anesthesia, and in two (12%) patients with syringomyelia. There was one (3%) reported case of aspiration pneumonia with general anesthesia.

CONCLUSIONS

The findings suggest that anesthetic complications occur infrequently in patients with ACM-I regardless of the anesthetic management. Although institutional preference in anesthetic and obstetric care appears to drive patient management, the findings suggest that an individualized approach has favorable outcomes in this population.

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.

Whole exome sequencing in three families segregating a pediatric case of sarcoidosis

BACKGROUND

Sarcoidosis (OMIM 181000) is a multi-systemic granulomatous disorder of unknown origin. Despite multiple genome-wide association (GWAS) studies, no major pathogenic pathways have been identified to date. To find out relevant sarcoidosis predisposing genes, we searched for de novo and recessive mutations in 3 young probands with sarcoidosis and their healthy parents using a whole-exome sequencing (WES) methodology.

METHODS

From the SARCFAM project based on a national network collecting familial cases of sarcoidosis, we selected three families (trios) in which a child, despite healthy parents, develop the disease before age 15 yr. Each trio was genotyped by WES (Illumina HiSEQ 2500) and we selected the gene variants segregating as 1) new mutations only occurring in affected children and 2) as recessive traits transmitted from each parents. The identified coding variants were compared between the three families. Allelic frequencies and in silico functional results were analyzed using ExAC, SIFT and Polyphenv2 databases. The clinical and genetic studies were registered by the ClinicalTrials.gov - Protocol Registration and Results System (PRS) ( https://clinicaltrials.gov ) receipt under the reference NCT02829853 and has been approved by the ethical committee (CPP LYON SUD EST - 2 - REF IRB 00009118 - September 21, 2016).

RESULTS

We identified 37 genes sharing coding variants occurring either as recessive mutations in at least 2 trios or de novo mutations in one of the three affected children. The genes were classified according to their potential roles in immunity related pathways: 9 to autophagy and intracellular trafficking, 6 to G-proteins regulation, 4 to T-cell activation, 4 to cell cycle and immune synapse, 2 to innate immunity. Ten of the 37 genes were studied in a bibliographic way to evaluate the functional link with sarcoidosis.

CONCLUSIONS

Whole exome analysis of case-parent trios is useful for the identification of genes predisposing to complex genetic diseases as sarcoidosis. Our data identified 37 genes that could be putatively linked to a pediatric form of sarcoidosis in three trios. Our in-depth focus on 10 of these 37 genes may suggest that the formation of the characteristic lesion in sarcoidosis, granuloma, results from combined deficits in autophagy and intracellular trafficking (ex: Sec16A, AP5B1 and RREB1), G-proteins regulation (ex: OBSCN, CTTND2 and DNAH11), T-cell activation (ex: IDO2, IGSF3), mitosis and/or immune synapse (ex: SPICE1 and KNL1). The significance of these findings needs to be confirmed by functional tests on selected gene variants.

Shared genetic predisposition in rheumatoid arthritis-interstitial lung disease and familial pulmonary fibrosis

Despite its high prevalence and mortality, little is known about the pathogenesis of rheumatoid arthritis-associated interstitial lung disease (RA-ILD). Given that familial pulmonary fibrosis (FPF) and RA-ILD frequently share the usual pattern of interstitial pneumonia and common environmental risk factors, we hypothesised that the two diseases might share additional risk factors, including FPF-linked genes. Our aim was to identify coding mutations of FPF-risk genes associated with RA-ILD.We used whole exome sequencing (WES), followed by restricted analysis of a discrete number of FPF-linked genes and performed a burden test to assess the excess number of mutations in RA-ILD patients compared to controls.Among the 101 RA-ILD patients included, 12 (11.9%) had 13 WES-identified heterozygous mutations in the TERT, RTEL1, PARN or SFTPC coding regions. The burden test, based on 81 RA-ILD patients and 1010 controls of European ancestry, revealed an excess of TERT, RTEL1, PARN or SFTPC mutations in RA-ILD patients (OR 3.17, 95% CI 1.53-6.12; p=9.45×10^-4). Telomeres were shorter in RA-ILD patients with a TERT, RTEL1 or PARN mutation than in controls (p=2.87×10^-2).Our results support the contribution of FPF-linked genes to RA-ILD susceptibility.