Pulmonary Fibrosis in Children

Pulmonary fibrosis may begin in infancy: from childhood to adult interstitial lung disease

BACKGROUND

Childhood interstitial lung disease (chILD) encompasses a group of rare heterogeneous respiratory conditions associated with significant morbidity and mortality. Reports suggest that many patients diagnosed with chILD continue to have potentially progressive or fibrosing disease into adulthood. Over the last decade, the spectrum of conditions within chILD has widened substantially, with the discovery of novel entities through advanced genetic testing. However, most evidence is often limited to small case series, with reports disseminated across an array of subspecialty, clinical and molecular journals. In particular, the frequency, management and outcome of paediatric pulmonary fibrosis is not well characterised, unlike in adults, where clear diagnosis and treatment guidelines are available.

METHODS AND RESULTS

This review assesses the current understanding of pulmonary fibrosis in chILD. Based on registry data, we have provisionally estimated the occurrence of fibrosis in various manifestations of chILD, with 47 different potentially fibrotic chILD entities identified. Published evidence for fibrosis in the spectrum of chILD entities is assessed, and current and future issues in management of pulmonary fibrosis in childhood, continuing into adulthood, are considered.

CONCLUSIONS

There is a need for improved knowledge of chILD among pulmonologists to optimise the transition of care from paediatric to adult facilities. Updated evidence-based guidelines are needed that incorporate recommendations for the diagnosis and management of immune-mediated disorders, as well as chILD in older children approaching adulthood.

Fibrotic lung diseases in children

In children, pulmonary fibrosis (PF) is an extremely unusual entity that can be observed in some types of interstitial lung disease (ILD). Defining whether ILD is accompanied by PF is important for targeted therapy. Algorithm for the diagnosis of PF in children is not clearly established. Besides, the clinical, radiological, and histological definitions commonly used to diagnose particularly the cases of idiopathic PF in adult patients, is not applicable to pediatric cases. However, a few studies conducted in children offer good exemplary diagnostic approach to fibrosing ILD. Thorax high resonance computed tomography and/or lung biopsy scanning can provide valuable information about PF. Another issue that has not been clearly established is when to start antifibrotic treatment in pediatric patients with PF. The objective of this current review is to provide a comprehensive overview of pediatric PF by drawing upon adult research, particularly focusing on the areas of uncertainty.

Rising cases of drug-induced pulmonary fibrosis: Analysis of the Food and Drug Administration Adverse Event Reporting System (FAERS) database, 2000-2022

PURPOSE

Pulmonary fibrosis (PF) is a severe, progressive disease, which may be caused by exposure to certain medications.

METHODS

We queried the U.S. FDA Adverse Event Reporting System (FAERS) from 2000 to 2022, using the search terms "pulmonary fibrosis" and "idiopathic pulmonary fibrosis" and excluded reports with patients under the age of 18 years, and patients with unknown sex or age. Reports were sorted by generic drug names, counted, and plotted over time using a best-fit trendline based on an exponential function.

RESULTS

From 2000 to 2022, there were 24 095 935 adverse drug events reported in FAERS, of which 17 520 (0.07%) were reported as PF. After excluding reports containing patients with unknown age (5255, 30%), sex (122, 0.7%), and age below 18 years old (155, 0.9%), our study included 11 988 reports. The mean age of the study sample was 66.5 ± 13.1 years, and 6248 patients (52.1%) were male. Plotting the 11 988 reports by year revealed an exponential best fit line (R2 = 0.88) with a positive slope over time. The top five drug classes associated with PF were disease modifying antirheumatic drugs (DMARDs, 39.4%), antineoplastic agents (26.4%), cardiovascular agents (12.6%), corticosteroids (4.6%), and immunosuppressive agents (4.0%).

CONCLUSION

A 23-year analysis of the FAERS database revealed exponentially increasing adverse event reports of PF. Significant annual increases in reporting of PF suspected with DMARDs and antineoplastic agents were identified. Our study highlights important trends, which should be used to guide PF research related to drugs of potential importance.

Imaging of pulmonary fibrosis in children: A review, with proposed diagnostic criteria

Computed tomography (CT) imaging findings of pulmonary fibrosis are well established for adults and have been shown to correlate with prognosis and outcome. Recognition of fibrotic CT findings in children is more limited. With approved treatments for adult pulmonary fibrosis, it has become critical to define CT criteria for fibrosis in children, to identify patients in need of treatment and those eligible for clinical trials. Understanding how pediatric fibrosis compares with idiopathic pulmonary fibrosis and other causes of fibrosis in adults is increasingly important as these patients transition to adult care teams. Here, we review what is known regarding the features of pulmonary fibrosis in children compared with adults. Pulmonary fibrosis in children may be associated with genetic surfactant dysfunction disorders, autoimmune systemic disorders, and complications after radiation, chemotherapy, transplantation, and other exposures. Rather than a basal-predominant usual interstitial pneumonia pattern with honeycombing, pediatric fibrosis is primarily characterized by reticulation, traction bronchiectasis, architectural distortion, or cystic lucencies/abnormalities. Ground-glass opacities are more frequent in children with fibrotic interstitial lung disease than adults, and disease distribution appears more diffuse, without clearly defined axial or craniocaudal predominance. Following discussion and consensus amongst a panel of expert radiologists, pathologists and physicians, distinctive disease features were integrated to develop criteria for the first global Phase III trial in children with pulmonary fibrosis.

Lung biopsies in infants and children in critical care situation

INTRODUCTION

Lung biopsy is considered as the last step investigation for diagnosing lung diseases; however, its indication must be carefully balanced with its invasiveness. The present study aims to evaluate the diagnostic yield of lung biopsy in critically ill patients hospitalized in the pediatric intensive care unit (ICU).

MATERIAL AND METHODS

Children who underwent a lung biopsy in the ICU between 1995 and 2022 were included. Biopsies performed in the operating room and post-mortem biopsies were excluded.

RESULTS

Thirty-one patients were included, with a median age of 18 days (2 days to 10.8 years); 21 (67.7%) were newborns. All patients required invasive mechanical ventilation, 26 (89.7%) had a pulmonary hypertension, and 22 (70.9%) were placed under extracorporeal membrane oxygenation (ECMO). The lung biopsy led to a diagnosis in 81% of the patients. The diagnostic reliability seemed to decrease with age (95% in newborns, 71% in 1 month to 2 years and 0/3 patients aged over 2 years old). Diffuse developmental disorders of the lung accounted for 15 (49%) patients, primarily alveolar capillary dysplasia, followed by surfactant disorders in 5 (16%) patients. Complications occurred in 9/31 (29%) patients including eight under ECMO, with massive hemorrhages in seven cases.

DISCUSSION AND CONCLUSION

In critical situations, lung biopsy should be performed. Lung biopsy is a reliable diagnostic procedure for neonates in critical situation when a diffuse developmental disorder of the lung is suspected. The majority of lung biopsy complication was associated with the use of ECMO. The prospective evaluation of the complications of such procedure under ECMO, and particularly over 10 days of ECMO and in children over 2-year-old remains to be ascertained.

Pulmonary fibrosis treatment in children - What have we learnt from studies in adults?

Pulmonary fibrosis (PF) in children is a rare complication of specific forms of childhood interstitial lung diseases (chILD) with extremely limited scientific evidence to guide optimal management. Whilst there continues to be significant progress in PF management for adult populations, paediatric guidelines have stagnated. New anti-fibrotic medications (nintedanib and pirfenidone) are finding regular use amongst adult PF patients but remain largely unstudied and untested in children. Although there are major differences between the two age-group populations, it is useful to learn from the evolution of adult PF management, especially in the absence of dedicated paediatric studies. Whilst there have been recent trials aimed at assessing the safety and efficacy of drugs such as nintedanib and hydroxychloroquine, there is still a dire need for more research aimed at further assessing current treatment practices and evaluating the safety and efficacy of new emerging treatments in the paediatric population.

Childhood Interstitial Lung Disease

Childhood interstitial lung disease (chILD) is a heterogeneous group of diseases with various clinical and imaging findings. The incidence and prevalence have increased in recent years, probably due to better comprehension of these rare diseases and increased awareness among physicians. chILDs present with nonspecific pulmonary symptoms, such as tachypnea, hypoxemia, cough, rales, and failure to thrive. Unnecessary invasive procedures can be avoided if specific mutations are detected through genetic examinations or if typical imaging patterns are recognized on computed tomography. Disease knowledge and targeted therapies are improving through international collaboration. Pulmonary involvement in systemic diseases is not uncommon. Pulmonary involvement may be the first finding in connective tissue diseases. This review aims to present a systematic patient-targeted approach to the diagnosis of chILD.

Fibrosing Interstitial Lung Disease in Children: An HRCT-Based Analysis

OBJECTIVE

To determine high resolution CT (HRCT) patterns of pulmonary fibrosis (PF) in children; and their etiological correlates.

METHODS

This was a retrospective study involving 149 children with diffuse lung disease (DLD). Patterns of involvement were classified based on dominant lung finding as ground glass opacity (GGO) dominant, nodule dominant, cystic lung disease, or PF. Patterns of PF were classified based on distribution and morphology into airway centric fibrosis (ACF), subpleural fibrosis (SPF), progressive massive fibrosis (PMF) and fibrocavitary. A comparison was made between the two dominant groups for apicobasal distribution, associated findings (GGO, nodules, cysts), and pulmonary artery hypertension (PAH).

RESULTS

Nineteen patients showed PF on HRCT. ACF was commonest (52.6%), followed by SPF (42.1%). The common etiology was sarcoidosis (30%) in ACF, and connective tissue disorders (CTD) (50%) in SPF. Significant difference was found between ACF and SPF in apicobasal distribution (p = 0.04), presence of nodules (p = 0.03), and cysts (p = 0.02).

CONCLUSION

PF may present as an end stage of several childhood lung diseases. PF on imaging has discernible morphological patterns that correlate with underlying etiology.

TLR4/ MyD88/NF-κB signaling pathway involved in the protective effect of diacerein against lung fibrosis in rats

PURPOSE

Pulmonary fibrosis (PF) is an inescapable problem. Diacerein, a chondro-protective drug, has antioxidant and anti-inflammatory effects. Its effect on PF injury has not yet been fully clarified. Therefore, the current study aimed to detect its protective effect on lung tissue with the explanation of possible underlying mechanisms.

METHODS

Adult male albino rats were assigned to four groups: control group, diacerein control group, PF non-treated group, and PF diacerein pretreated group. Lung tissue oxidative stress parameters, inflammatory biomarkers mainly Toll-like receptors-4 (TLR4), and myeloid differentiation factor 88 (MyD88) levels were determined. Histopathological examination of lung tissue and immunohistochemical studies of nuclear factor-kappa B (NF-κB), and transforming growth factor- β (TGF-β) were also done.

RESULTS

Diacerein pretreatment has the ability to restore the PF damaging effect, proved by the reduction of the oxidative stress and lung tissue inflammation via downregulation of TLR4/NF-κB signaling pathway together with the restoration of TGF-β level and improvement of the histopathological and immunohistochemical study findings in the lung tissue.

CONCLUSION

These results suggested the protective effect of diacerein on PF relies on its antioxidant and anti-inflammatory effects reducing TLR4/NF-κB signaling pathway.

Idiopathic pulmonary fibrosis therapy development: a clinical pharmacology perspective

Drug development for idiopathic pulmonary fibrosis (IPF) has been challenging due to poorly understood disease etiology, unpredictable disease progression, highly heterogeneous patient populations, and a lack of robust pharmacodynamic biomarkers. Moreover, because lung biopsy is invasive and dangerous, making the extent of fibrosis as a direct longitudinal measurement of IPF disease progression unfeasible, most clinical trials studying IPF can only assess progression of fibrosis indirectly through surrogate measures. This review discusses current state-of-art practices, identifies knowledge gaps, and brainstorms development opportunities for preclinical to clinical translation, clinical populations, pharmacodynamic endpoints, and dose optimization strategies. This article highlights clinical pharmacology perspectives in leveraging real-world data as well as modeling and simulation, special population considerations, and patient-centric approaches for designing future studies.

Minimal important difference in childhood interstitial lung diseases

Background

Monitoring disease progression in childhood interstitial lung diseases (chILD) is essential. No information for the minimal important difference (MID), which is defined as the smallest change in a parameter that is perceived as important prompting a clinician to change the treatment, is available. We calculated MIDs for vital signs (respiratory rate, peripheral oxygen saturation in room air, Fan severity score) and health-related quality of life (HrQoL) scores.

Methods

This study used data from the Kids Lung Register, which is a web-based management platform that collects data of rare paediatric lung disorders with a focus on chILD. Data of vital signs and HrQoL scores (Health Status Questionnaire, chILD-specific questionnaire and PedsQL V.4.0) were collected. MIDs were calculated according to distribution-based (one-third SD) and anchor-based methods (using forced expiratory volume in 1 s and forced vital capacity) as anchors.

Results

Baseline data of 774 children were used to calculate the following MIDs: respiratory rate 1.3 (z-score), O2saturation in room air 3.0%, Fan severity score 0.2–0.4, Health Status Questionnaire 0.4–0.8, chILD-specific questionnaire 4.4%–8.2%, physical health summary score 7.8%–8.9%, psychosocial health summary score 3.4%–6.9% and total score 5.1%–7.4%. Results of the responsiveness analysis generally agreed with the MIDs calculated.

Conclusions

For the first time, we provide estimates of MIDs for vital signs and HrQoL scores in a large cohort of chILD using different methods.

Randomized controlled phase 2 trial of hydroxychloroquine in childhood interstitial lung disease

BACKGROUND

No results of controlled trials are available for any of the few treatments offered to children with interstitial lung diseases (chILD). We evaluated hydroxychloroquine (HCQ) in a phase 2, prospective, multicentre, 1:1-randomized, double-blind, placebo-controlled, parallel-group/crossover trial. HCQ (START arm) or placebo were given for 4 weeks. Then all subjects received HCQ for another 4 weeks. In the STOP arm subjects already taking HCQ were randomized to 12 weeks of HCQ or placebo (= withdrawal of HCQ). Then all subjects stopped treatment and were observed for another 12 weeks.

RESULTS

26 subjects were included in the START arm, 9 in the STOP arm, of these four subjects participated in both arms. The primary endpoint, presence or absence of a response to treatment, assessed as oxygenation (calculated from a change in transcutaneous O₂-saturation of ≥ 5%, respiratory rate ≥ 20% or level of respiratory support), did not differ between placebo and HCQ groups. Secondary endpoints including change of O₂-saturation ≥ 3%, health related quality of life, pulmonary function and 6-min-walk-test distance, were not different between groups. Finally combining all placebo and all HCQ treatment periods did not identify significant treatment effects. Overall effect sizes were small. HCQ was well tolerated, adverse events were not different between placebo and HCQ.

CONCLUSIONS

Acknowledging important shortcomings of the study, including a small study population, the treatment duration, lack of outcomes like lung function testing below age of 6 years, the small effect size of HCQ treatment observed requires careful reassessments of prescriptions in everyday practice (EudraCT-Nr.: 2013-003714-40, www.clinicaltrialsregister.eu , registered 02.07.2013). Registration The study was registered on 2 July 2013 (Eudra-CT Number: 2013-003714-40), whereas the approval by BfArM was received 24.11.2014, followed by the approval by the lead EC of the University Hospital Munich on 20.01.2015. At clinicaltrials.gov the trial was additionally registered on November 8, 2015 (NCT02615938).

RaDiCo, the French national research program on rare disease cohorts

BACKGROUND

Rare diseases (RDs) affect nearly 3 million people in France and at least 26-30 million people in Europe. These diseases, which represent a major medical concern, are mainly of genetic origin, often chronic, progressive, degenerative, life threatening and disabling, accounting for more than one third of all deaths occurring during infancy. In this context, there are needs for coordinated information on RDs at national/international levels, based on high quality, interoperable and sharable data. The main objective of the RaDiCo (Rare Disease Cohorts) program, coordinated by Inserm, was the development of RD e-cohorts via a national platform. The cohort projects were selected through a national call in 2014. The e-cohorts are supported by an interoperable platform, equivalent to an infrastructure, constructed on the "cloud computing" principle and in compliance with the European General Data Protection Regulation. It is dedicated to allow a continuous monitoring of data quality and consistency, in line with the French Health Data Hub.

RESULTS

Depending on cohorts, the objectives are to describe the natural history of the studied RD(s), identify the underlying disease genes, establish phenotype-genotype correlations, decipher their pathophysiology, assess their societal and medico-economic impact, and/or identify patients eligible for new therapeutic approaches. Inclusion of prevalent and incident cases started at the end of 2016. As of April 2021, 5558 patients have been included within 13 RD e-cohorts covering 67 diseases integrated in 10 European Reference Networks and contributing to the European Joint Program on RDs. Several original results have been obtained in relation with the secondary objectives of the RaDiCo cohorts. They deal with discovery of new disease genes, assessment of treatment management, deciphering the underlying pathophysiological mechanisms, diagnostic approaches, genotype-phenotype relationships, development and validation of questionnaires relative to disease burden, or methodological aspects.

CONCLUSION

RaDiCo currently hosts 13 RD e-cohorts on a sharable and interoperable platform constructed on the "cloud computing" principle. New RD e-cohorts at the European and international levels are targeted.

Age-Dependent Chronic Lung Injury and Pulmonary Fibrosis following Single Exposure to Hydrochloric Acid

Exposure to hydrochloric acid (HCl) represents a threat to public health. Children may inhale higher doses and develop greater injury because of their smaller airways and faster respiratory rate. We have developed a mouse model of pediatric exposure to HCl by intratracheally instilling p24 mice (mice 24 days old; 8-10 g) with 2 µL/g 0.1 N HCl, and compared the profile of lung injury to that in HCl-instilled adults (10 weeks old; 25-30 g) and their age-matched saline controls. After 30 days, alveolar inflammation was observed with increased proteinosis and mononuclear cells in the bronchoalveolar lavage fluid (BALF) in both HCl-instilled groups. Young p24 animals-but not adults-exhibited higher NLR family pyrin domain containing 3 (NLRP3) inflammasome levels. Increased amounts of Transforming Growth Factor-β (TGF-β) mRNA and its intracellular canonical and non-canonical pathways (p-Smad2 and p-ERK) were found in the lungs of both young and adult HCl-instilled mice. Constitutive age-related differences were observed in the levels of heat shock protein family (HSP70 and HSP90). HCl equally provoked the deposition of collagen and fibronectin; however, significant age-dependent differences were observed in the increase in elastin and tenascin C mRNA. HCl induced pulmonary fibrosis with an increased Ashcroft score, which was higher in adults, and a reduction in alveolar Mean Alveolar Linear Intercept (MALI). Young mice developed increased Newtonian resistance (Rn) and lower PV loops, while adults showed a higher respiratory system resistance and elastance. This data indicate that young p24 mice can suffer long-term complications from a single exposure to HCl, and can develop chronic lung injury characterized by a stronger persistent inflammation and lesser fibrotic pattern, mostly in the airways, differently from adults. Further data are required to characterize HCl time- and dose-dependent injury in young animals and to identify new key-molecular targets.

Functional assessment and phenotypic heterogeneity of SFTPA1 and SFTPA2 mutations in interstitial lung diseases and lung cancer

INTRODUCTION

Interstitial lung diseases (ILDs) can be caused by mutations in the SFTPA1 and SFTPA2 genes, which encode the surfactant protein (SP) complex SP-A. Only 11 SFTPA1 or SFTPA2 mutations have so far been reported worldwide, of which five have been functionally assessed. In the framework of ILD molecular diagnosis, we identified 14 independent patients with pathogenic SFTPA1 or SFTPA2 mutations. The present study aimed to functionally assess the 11 different mutations identified and to accurately describe the disease phenotype of the patients and their affected relatives.

METHODS

The consequences of the 11 SFTPA1 or SFTPA2 mutations were analysed both in vitro, by studying the production and secretion of the corresponding mutated proteins and ex vivo, by analysing SP-A expression in lung tissue samples. The associated disease phenotypes were documented.

RESULTS

For the 11 identified mutations, protein production was preserved but secretion was abolished. The expression pattern of lung SP-A available in six patients was altered and the family history reported ILD and/or lung adenocarcinoma in 13 out of 14 families (93%). Among the 28 SFTPA1 or SFTPA2 mutation carriers, the mean age at ILD onset was 45 years (range 0.6-65 years) and 48% underwent lung transplantation (mean age 51 years). Seven carriers were asymptomatic.

DISCUSSION

This study, which expands the molecular and clinical spectrum of SP-A disorders, shows that pathogenic SFTPA1 or SFTPA2 mutations share similar consequences for SP-A secretion in cell models and in lung tissue immunostaining, whereas they are associated with a highly variable phenotypic expression of disease, ranging from severe forms requiring lung transplantation to incomplete penetrance.

Children's Interstitial and Diffuse Lung Diseases (ChILD) in 2020

The term children interstitial lung diseases (chILD) refers to a heterogeneous group of rare diseases that diffusely affect the lung. ChILD specific to children younger than 2 years of age include diffuse developmental disorders, growth abnormalities, specific conditions of undefined etiology (neuroendocrine cell hyperplasia of infancy and pulmonary interstitial glycogenosis) and surfactant protein disorders. Clinical manifestations are highly variable, ranging from the absence of relevant symptoms to a severe onset. Most commonly, chILD presents with nonspecific respiratory signs and symptoms, such as dyspnea, polypnea, dry cough, wheezing, recurrent respiratory infections and exercise intolerance. In the diagnostic approach to a child with suspected ILD, chest high resolution computed tomography and genetic tests play a central role. Then, if the diagnosis remains uncertain, laryngotracheal-bronchoscopy and lung biopsy are needed. Pharmacological treatment is mostly empiric and based on anti-inflammatory and immunomodulatory drugs including corticosteroids, hydroxychloroquine and azithromycin. Despite chILD overall rarity, pediatric pulmonologists must be familiar with these diseases in order to carry out a timely diagnosis and patient treatment.

Atractylenolide III attenuates bleomycin-induced experimental pulmonary fibrosis and oxidative stress in rat model via Nrf2/NQO1/HO-1 pathway activation

BACKGROUND

Bleomycin (BLM) is a chemotherapy drug used to treat cancer, one of which side effects is that it can lead to pulmonary fibrosis (PF). Atractylenoide III (AtrIII), derived from the dried roots of rhizoma atractylodis of compositae, is one of the main active substances of rhizoma atractylodis. It has anti-inflammatory, anti-tumor and other effects. This study aimed to investigate whether AtrIII alleviated BLM-induced PF and oxidative stress in rats through the nuclear factor erythroid-2-related factor 2/NQO1,NAD(P)H:quinine oxidoreductase 1/Heme oxygenase-1 (Nrf2/NQO1/HO-1) pathway.

METHODS

A BLM-induced pulmonary fibrosis model in SD rats was established. The respiratory dynamics were evaluated by using Wholebody flow-through plethysmography. Lung injury and pulmonary fibrosis were observed by Hematoxylin-eosin (HE) and Masson staining. Apoptosis was assay by Tunel assay. Inflammatory factors were detected with commercial kits. Expression of mRNAs and proteins were detected by RT-qPCR and Western blot, respectively.

RESULTS

AtrIII (1.2, 2.4 mg/kg) improved the lung injury and lung function in the BLM-induced Sprague-Dawley (SD) rats. AtrIII reduced the apoptosis rate and protein expression of Caspase-3 and Caspase-9. AtrIII (1.2, 2.4 mg/kg) decrease the pulmonary fibrosis damage and protein expression transforming growth factor-β (TGF-β) and α-smooth muscle actin (α-SMA). AtrIII also down-regulated the levels of interleukin 6 (IL-6), inductible nitric oxide synthase (iNOS) and tumor necrosis factor-α (TNF-α), while up-regulated the level of IL-10 in peripheral blood serum. Moreover, AtrIII (1.2, 2.4 mg/kg) increased the activity of superoxide dismutase (SOD) and glutathione (GSH), while decreased the malondialdehyde (MDA) content and lactate dehydrogenase (LDH) activity. AtrIII (1.2, 2.4 mg/kg) increased the levels of Nrf2, NQO1 and HO-1. In addition, AtrIII reversed the effects of Nrf2 interference on pulmonary fibrosis damage, decreased SOD and GSH activity, and increased MDA content.

CONCLUSION

AtrIII could attenuate the pulmonary fibrosis and reliev oxidative stress through the Nrf2/NQO1/ HO-1 pathway.

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.