An official American Thoracic Society clinical practice guideline: classification, evaluation, and management of childhood interstitial lung disease in infancy

Interstitial lung disease as an indication for pediatric lung transplant

Interstitial lung disease can be an indication for lung transplant at any age, but it is a particularly common indication for lung transplant in infants. Nevertheless, not all interstitial lung diseases will lead to lung transplant in childhood. Genetic testing has aided the identification of these diseases in children. In severely affected patients, however, definitive diagnosis is not always necessary to consider referral to a transplant center. At experienced transplant centers, a multidisciplinary team educates patient families and aids in the transplant evaluation of children with interstitial lung disease. Children who have undergone transplant require lifetime immunosuppression and close surveillance, but can enjoy good quality of life for years following surgery.

Contemporary and emerging technologies for research in children's rare and interstitial lung disease

Although recent decades have seen the identification, classification and discovery of the genetic basis of many children's interstitial and rare lung disease (chILD) disorders, detailed understanding of pathogenesis and specific therapies are still lacking for most of them. Fortunately, a revolution of technological advancements has created new opportunities to address these critical knowledge gaps. High-throughput sequencing has facilitated analysis of transcription of thousands of genes in thousands of single cells, creating tremendous breakthroughs in understanding normal and diseased cellular biology. Spatial techniques allow analysis of transcriptomes and proteomes at the subcellular level in the context of tissue architecture, in many cases even in formalin-fixed, paraffin-embedded specimens. Gene editing techniques allow creation of "humanized" animal models in a shorter time frame, for improved knowledge and preclinical therapeutic testing. Regenerative medicine approaches and bioengineering advancements facilitate the creation of patient-derived induced pluripotent stem cells and their differentiation into tissue-specific cell types which can be studied in multicellular "organoids" or "organ-on-a-chip" approaches. These technologies, singly and in combination, are already being applied to gain new biological insights into chILD disorders. The time is ripe to systematically apply these technologies to chILD, together with sophisticated data science approaches, to improve both biological understanding and disease-specific therapy.

Clinical scope and healthcare utilization in childhood interstitial lung disease at a tertiary center

Childhood interstitial lung disease (chILD) is a heterogeneous group of diffuse lung diseases that can be challenging to diagnose. With relative rarity of individual entities, data are limited on disease prevalence, care patterns, and healthcare utilization. The objective of this study was to evaluate chILD prevalence and review diagnostic and clinical care patterns at our center. A single-center, retrospective cohort study was conducted of patients receiving care at the Children's Hospital of Philadelphia (CHOP) between 1 January 2019 and 31 December 2021. Through query of selected ICD-10 billing codes relevant for chILD and medical chart review, a total of 306 patients were identified receiving pulmonary care during this period. Respiratory symptom onset was documented to have developed before 2 years of age for 40% of cases. The most common diagnostic categories included those with oncologic disease (21.2%), bronchiolitis obliterans (10.1%), and connective tissue disease (9.5%). Genetic testing was performed in 49% of cases, while 36% underwent lung biopsy. Hospitalization at CHOP had occurred for 80.4% of patients, with 45.1% ever hospitalized in an intensive care unit. One-third of children had required chronic supplemental oxygen. Seven (2.3%) patients died during this 3-year period. Collectively, these data demonstrate the scope of chILD and extent of health care utilization at a large volume tertiary care center. This approach to cohort identification and EMR-driven data collection in chILD provides new opportunities for cohort analysis and will inform the feasibility of future studies.

Imaging in Pediatric Lung Disease: Current Practice and Future Directions

Pediatric diseases present differently from adult diseases and imaging forms a cornerstone of modern pediatric care through differential diagnosis, disease monitoring, and measuring response to therapy. Imaging is especially well suited to providing novel insights into the underlying mechanisms driving disease through structural and functional imaging. In this review, we describe key imaging findings in standard-of-care and state-of-the-art techniques in pediatric and adult diseases with origins in childhood. We examine applications in small airways disease, large airway disease, diseases of maturity, interstitial lung disease, neuromuscular disease, congenital disease, and pulmonary infection.

Approach to the patient with Childhood Interstitial and Diffuse Lung Disease

Childhood Interstitial and Diffuse Lung Disease (chILD) encompasses a group of rare, chronic lung disorders in infants and children with overlapping clinical features but diverse etiologies. The clinical presentation of chILD is of chronic or recurring respiratory signs and symptoms, often including increased work of breathing and hypoxia, with diffuse radiographic abnormalities on chest imaging. Recognition can be challenging since some clinical features overlap with those of more common pediatric respiratory diseases including asthma and recurrent viral infections, among others. chILD should be considered as an underlying diagnosis when a patient's respiratory symptoms seem disproportionate to the clinical scenario and/or persist. The diagnostic process involves multiple steps and is tailored to the individual patient. Nearly all children will undergo imaging and pulmonary function testing, many will undergo bronchoscopy with bronchoalveolar lavage, many will receive genetic testing, and some will require lung biopsy. Treatment includes preventive care, evaluation for comorbidities, pharmacotherapy according to diagnosis, and ongoing disease surveillance, including revisiting genetic and histopathologic results as new clinical information becomes available and as our understanding of these rare disorders improves. The purpose of this review is to provide a broad approach to the diagnosis and management of patients with chILD.

Learning to make a difference for chILD: Value creation through network collaboration and team science

Addressing the recognized challenges and inequalities in providing high quality healthcare for rare diseases such as children's interstitial lung disease (chILD) requires collaboration across institutional, geographical, discipline, and system boundaries. The Children's Interstitial Lung Disease Respiratory Network of Australia and New Zealand (chILDRANZ) is an example of a clinical network that brings together multidisciplinary health professionals for collaboration, peer learning, and advocacy with the goal of improving the diagnosis and management of this group of rare and ultra-rare conditions. This narrative review explores the multifaceted benefits arising from social learning spaces within rare disease clinical networks by applying the value creation framework. The operation of the chILDRANZ network is used as an example across the framework to highlight how value is generated, realized, and transferred within such collaborative clinical and research networks. The community of practice formed in the chILDRANZ multidisciplinary meetings provides a strong example of social learning that engages with the uncertainty inherent in rare disease diagnosis and management and pays attention to generate new knowledge and best practice to make a difference for children and families living with chILD. This review underscores international calls for further investment in, and support of, collaborative clinical networks and virtual centers of excellence for rare disease.

Genetic testing for diffuse lung diseases in children

Newly developing genomic technologies are an increasingly important part of clinical care and thus, it is not only important to understand the technologies and their limitations, but to also interpret the findings in an actionable fashion. Clinical geneticists and genetic counselors are now an integral part of the clinical team and are able to bridge the complexities of this rapidly changing science between the bedside clinicians and patients. This manuscript reviews the terminology, the current technology, some of the known genetic disorders that result in lung disease, and indications for genetic testing with associated caveats. Because this field is evolving quickly, we also provide links to websites that provide continuously updated information important for integrating genomic technology results into clinical decision-making.

Innovations in Childhood Interstitial and Diffuse Lung Disease

Children's interstitial and diffuse lung diseases (chILDs) are a heterogenous and diverse group of lung disorders presenting during childhood. Infants and children with chILD disorders present with respiratory signs and symptoms as well as diffuse lung imaging abnormalities. ChILD disorders are associated with significant health care resource utilization and high morbidity and mortality. The care of patients with chILD has been improved through multidisciplinary care, multicenter collaboration, and the establishment of patient research networks in the United Stated and abroad. This review details past and current innovations in the diagnosis and clinical care of children with chILD.

Advancements in imaging in ChILD

Interstitial and diffuse lung diseases in children constitute a range of congenital and acquired disorders. These disorders present with signs and symptoms of respiratory disease accompanied by diffuse radiographic changes. In many cases, radiographic findings are nonspecific, while in other disorders, chest computed tomography (CT) is diagnostic in the appropriate context. Regardless, chest imaging remains central in the evaluation of the patient with suspected childhood interstitial lung disease (chILD). Several newly described chILD entities, spanning both genetic and acquired etiologies, have imaging that aid in their diagnoses. Advances in CT scanning technology and CT analysis techniques continue to improve scan quality as well as expand use of chest CT as a research tool. Finally, ongoing research is expanding use of imaging modalities without ionizing radiation. Magnetic resonance imaging is being applied to investigate pulmonary structure and function, and ultrasound of the lung and pleura is a novel technique with an emerging role in chILD disorders. This review describes the current state of imaging in chILD including recently described diagnoses, advances in conventional imaging techniques and applications, and evolving new imaging modalities that expand the clinical and research roles for imaging in these disorders.

Lung biopsy in the diagnosis and management of chILD

Children's interstitial and diffuse lung disease (chILD) comprises a large number of diverse entities ranging from disorders of lung development, maturation and function unique in infancy to immune-mediated, environmental, vascular and other conditions overlapping with adult disease. Pathologic evaluation of the lung has played a central role in characterizing many of these disorders, resulting in revised nomenclature and classifications to help guide clinical management(1-4). Technological advancements are rapidly uncovering genetic and molecular underpinnings of these conditions, as well as widening the phenotypes which bridge adult disease, often reducing the perceived need for diagnostic lung biopsy. As such the decision to get a lung biopsy in chILD is frequently for rapid ascertainment of disease in a critically ill child or when clinical presentation, imaging and laboratory studies fail to provide a cohesive diagnosis needed for treatment. While there have been modifications in surgical procedures for lung biopsy that minimize postoperative morbidity, it remains a high-risk invasive procedure, especially in a medically complex patient(5). Thus, it is essential that the lung biopsy be handled properly to maximize diagnostic yield, including close communication between the clinician, radiologist, surgeon, and pathologist before biopsy to determine best sampling site(s) and prioritization of tissue utilization. This review provides an overview of optimal handling and evaluation of a surgical lung biopsy for suspected chILD, with emphasis on specific conditions in which pathologic features play a critical role in providing an integrated diagnosis and guiding management.

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.

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.

It Is Time to Get to Know the Neuroendocrine Cell Hyperplasia of Infancy

In the two decades that have elapsed since the initial proposal of neuroendocrine cell hyperplasia of infancy (NEHI), several hundred cases have been reported and researched. However, a comprehensive analysis of research progress remains absent from the literature. The present article endeavors to evaluate the current progress of NEHI research and offer a reference for the clinical management of this condition.

Interstitial lung disease in the newborn

Although relatively rare, interstitial lung diseases may present with respiratory distress in the newborn period. Most commonly these include developmental and growth disorders, disorders of surfactant synthesis and homeostasis, pulmonary interstitial glycogenosis, and neuroendocrine cell hyperplasia of infancy. Although the diagnosis of these disorders is sometimes made based on clinical presentation and imaging, due to the significant overlap between disorders and phenotypic variability, lung biopsy or, increasingly genetic testing is needed for diagnosis. These diseases may result in significant morbidity and mortality. Effective medical treatment options are in some cases limited and/or invasive. The genetic basis for some of these disorders has been identified, and with increased utilization of exome and whole genome sequencing even before lung biopsy, further insights into their genetic etiologies should become available.

Beyond Bronchopulmonary Dysplasia: A Comprehensive Review of Chronic Lung Diseases in Neonates

In neonates, pulmonary diseases such as bronchopulmonary dysplasia and other chronic lung diseases (CLDs) pose significant challenges due to their complexity and high degree of morbidity and mortality. This review discusses the etiology, pathophysiology, clinical presentation, and diagnostic criteria for these conditions, as well as current management strategies. The review also highlights recent advancements in understanding the pathophysiology of these diseases and evolving strategies for their management, including gene therapy and stem cell treatments. We emphasize how supportive care is useful in managing these diseases and underscore the importance of a multidisciplinary approach. Notably, we discuss the emerging role of personalized medicine, enabled by advances in genomics and precision therapeutics, in tailoring therapy according to an individual's genetic, biochemical, and lifestyle factors. We conclude with a discussion on future directions in research and treatment, emphasizing the importance of furthering our understanding of these conditions, improving diagnostic criteria, and exploring targeted treatment modalities. The review underscores the need for multicentric and longitudinal studies to improve preventative strategies and better understand long-term outcomes. Ultimately, a comprehensive, innovative, and patient-centered approach can enhance the quality of care and outcomes for neonates with CLDs.

Health-related quality scores in childhood interstitial lung disease: Good agreement between patient and caregiver reports

INTRODUCTION

Childhood interstitial lung disease (chILD) is a heterogeneous group of mostly chronic respiratory disorders. Assessment of health-related quality of life (HrQoL) in chILD has become increasingly important in clinical care and research. The aim of this study was to assess differences between patient-reported (self) and caregiver-reported (proxy) HrQoL scores.

METHODS

This study used data obtained from the chILD-EU Register. After inclusion (baseline), the patient's health status was followed up at predefined study visits. At each study visit, caregivers and patients were handed validated, age-specific HrQoL questionnaires. HrQoL data entered at baseline were used to compare self- and proxy-reported HrQoL scores. For the longitudinal analysis, we compared HrQoL scores between the baseline and the next follow-up visit.

RESULTS

No differences between patient- and caregiver-reported HrQoL scores were found for school functioning, chILD-specific questionnaire score, and physical health summary score. Self-reported HrQoL scores were higher for the subscales emotional functioning (77.4 vs. 70.7; p < .001), social functioning (81.9 vs. 76.2; p < .001), as well as psycho-social summary score (76.5 vs. 71.8; p < .001) and total score (74.7 vs. 70.8; <.001). The longitudinal analysis showed that a significant change in a patient-reported HrQoL score resulted in a significant change in a caregiver-reported HrQoL score after a mean time of 11.0 months (SD 9.4).

CONCLUSIONS

We found a good agreement between children- and caregiver-related HrQoL scores. In chILD, caregivers are able to sense changes in children's HrQoL scores over time and may be used as a proxy for children unable to complete HrQoL questionnaires.

A roadmap to precision treatments for familial pulmonary fibrosis

Interstitial lung diseases (ILDs) in adults and children (chILD) are a heterogeneous group of lung disorders leading to inflammation, abnormal tissue repair and scarring of the lung parenchyma often resulting in respiratory failure and death. Inherited factors directly cause, or contribute significantly to the risk of developing ILD, so called familial pulmonary fibrosis (FPF), and monogenic forms may have a poor prognosis and respond poorly to current treatments. Specific, variant-targeted or precision treatments are lacking. Clinical trials of repurposed drugs, anti-fibrotic medications and specific treatments are emerging but for many patients no interventions exist. We convened an expert working group to develop an overarching framework to address the existing research gaps in basic, translational, and clinical research and identified areas for future development of preclinical models, candidate medications and innovative clinical trials. In this Position Paper, we summarise working group discussions, recommendations, and unresolved questions concerning precision treatments for FPF.

ATS core curriculum 2023. Pediatric pulmonary medicine: Respiratory disorders in infants

The American Thoracic Society Core Curriculum updates clinicians annually in pediatric pulmonary disease. This is a summary of the Pediatric Pulmonary Medicine Core Curriculum presented at the 2023 American Thoracic Society International Conference. The respiratory disorders of infancy discussed in this year's review include: the care of the patient with bronchopulmonary dysplasia in the neonatal intensive care unit, clinical phenotypes and comorbidities; diffuse lung disease; pulmonary hypertension; central and obstructive sleep apnea. The care of infants with respiratory disorders often poses significant challenges to the general pediatric pulmonologist, sleep clinician, and neonatologist. This review aims to highlight the most clinically relevant aspects of the evaluation, management, and outcomes of infants with these key respiratory disorders, while emphasizing the importance of multidisciplinary care. Furthermore, this document summarizes essential aspects of genetic testing, novel imaging and treatment modalities, and includes multiple resources for clinical practice.

Mortality of Pediatric Surgical Lung Biopsies in Ontario, Canada, 2000-2019

Rationale: Surgical lung biopsies are often required for the definitive diagnosis of nonmalignant pediatric diffuse lung diseases; however, the literature on mortality after surgical lung biopsy in pediatric patients is sparse. Objectives: To determine the 30-day postoperative mortality rate after surgical lung biopsies for nonmalignant lung disease in pediatric patients in Ontario, Canada, and to identify risk factors associated with mortality. Methods: We performed an observational cohort study using population-based health administrative data available from ICES in Ontario, Canada, from 2000 to 2019. Cases were identified using the Canadian Classification of Health Interventions. Inclusion criteria were first surgical lung biopsies between 2000 and 2019 and age <18 years. Individuals with lung cancer, lung transplant, or missing data were excluded. A multivariable logistic regression model with generalized estimating equation was used to estimate the 30-day odds of mortality after surgical lung biopsy and to identify patient characteristics associated with increased mortality while accounting for clustering by hospital. Results: We identified 1,474 pediatric patients who underwent surgical lung biopsy in Ontario between 2000 and 2019. The overall mortality rates decreased over the study duration from 6.6% (2000-2004) to 3.0% (2015-2019). The study cohort for multivariate analyses consisted of 1,342 patients who had complete data. The pediatric mortality 30 days after surgical lung biopsy was 5.1% but was <1% in elective cases. Risk factors for increased mortality included open surgical lung biopsy (vs. video-assisted) (odds ratio [OR], 13.13; 95% confidence interval [CI], 3.76, 45.87; P < 0.001), nonelective procedure (OR, 11.74; 95% CI, 3.51, 39.27; P < 0.001), younger age (<3 mo) (OR, 6.04; 95% CI, 2.40, 15.22; P < 0.001), and higher comorbidity score (OR, 1.15; 95% CI, 1.05, 1.26; P = 0.003). Conclusions: Pediatric mortality postsurgical lung biopsy is not insignificant, particularly in nonelective procedures. Other important risk factors to consider when pursuing pathologic diagnosis include surgical approach, younger age, and higher comorbidity.

Incidence, prevalence, and pattern of medical service utilization of children's rare lung diseases in South Korea

INTRODUCTION

Children's rare lung diseases are a heterogeneous group of rare lung diseases with significant morbidity and mortality. There is very limited information on the incidence and prevalence of children's rare lung diseases in Asia. We investigated the nationwide incidence, prevalence, and pattern of medical service utilization of children's rare lung diseases in Korea.

METHODS

We studied patients who were diagnosed with rare lung diseases coded per International Statistical Classification of Diseases and Related Health Problems, 10th Edition and registered in the national rare diseases database of confirmed patients. Data was extracted from the Korean National Health Insurance Service Claims database over 2019-2021.

RESULTS

Average incidence rate was 12.9 new cases per million children per year, and average prevalence rate was 60.2 cases per million children during the study period of 2019-2021. We found that more than 65% of new cases were diagnosed before 2 years of age. ChILD, primary ciliary dyskinesia, and cystic fibrosis were usually diagnosed after 6 years of age. Congenital airway and lung anomalies were often diagnosed before 2 years of age. Busan and Gyeongsangnam-do residents tended to visit hospitals near their place of residence, while residents of other areas tended to visit hospitals in Seoul regardless of their area of residence.

CONCLUSIONS

We examined the epidemiology of rare lung diseases in children in South Korea. Our estimation of the incidence and prevalence could be used for sustainable health care and equitable distribution of health care resources.

Functional characterization of two novel NKX2-1 frameshift variants that cause pulmonary surfactant dysfunction

BACKGROUND

We aim to report two unrelated patients with pulmonary surfactant dysfunction (PSD) that carried two novel NKX2-1 frameshift variants, and evaluated the impact of these variants in vitro.

METHODS

We enrolled children with PSD and NKX2-1 variants, and collected their clinical information and follow-up data. We constructed wild-type (WT) and variant NKX2-1 plasmids and transfected them into A549 and HEK293T cells. The functional characterization of variants was then evaluated by qRT-PCR, western blot, immunofluorescence, electrophoretic mobility shift assay, and dual-luciferase reporter assay.

RESULTS

Two novel heterozygous frameshift variants of NKX2-1, i.e., c.705delC (Gly236Alafs*29) and c.313_316 dup (Asn106Lysfs*304), were identified in children from two unrelated families. We discerned attenuated mRNA and protein expression in the Asn106Lysfs*304 variant, and reduced DNA -binding as well as transcriptional activation capabilities in both variants. While the Asn106Lysfs*304 variant lost its synergistic interactions with PAX8 and TAZ, the Gly236Alafs*29 variant partially retained its residual transcriptional activation capabilities and synergistic interactions with PAX8 and TAZ.

CONCLUSIONS

We reported on two children with two novel NKX2-1 frameshift variants. In vitro experiments revealed that the two frameshift variants have common and different mechanisms based on the loss or conservation of domains, which partially explained the phenotypical heterogeneity.

IMPACT

Pulmonary surfactant dysfunction is a rare heterogeneous disease that exhibits a great burden on children's quality of life. We reported two novel NKX2-1 frameshift variants carried by two children with different clinical phenotypes, thus broadening our knowledge base of gene variations and phenotypes in NKX2-1. We performed an in vitro study and uncovered different pathogenic mechanisms underlying the actions of two novel variants, and thereby partially explained the mechanisms of phenotypical heterogeneity caused by NKX2-1 variants.

Pulmonary interstitial glycogenosis in two neonates: Early recognition and use of corticosteroids

Pulmonary interstitial glycogenosis (PIG) is known to be associated with a wide variety of congenital conditions, though the extent to which PIG contributes to clinical presentation and outcomes in infants remains controversial. We describe two cases of infants with congenital anomalies and respiratory distress at birth who were diagnosed with PIG with differing clinical courses and response to methylprednisolone therapy. These cases highlight the importance of improved recognition of PIG and uncertainties about which patients may benefit from treatment.

The significance of multidisciplinary team meetings in diagnosing and managing childhood interstitial lung disease within the RespiRare network

INTRODUCTION

Childhood Interstitial Lung Disease (chILD) represents a rare and severe group of diseases for which the etiologic workup, classification, and management remain a challenge for most pediatric pulmonologists. In France in 2018, the RespiRare network established the first multidisciplinary team meetings (MDTm) dedicated to chILD. This study aims to investigate the impact of MDTm in chILD diagnosis and management as well as user satisfaction.

METHODS

The MDTm took place on a monthly basis through video conferences. The participants consisted of a quorum and included pediatric pulmonologists, radiologists, geneticists, and pulmonologists, with an average of 10.5 participants per meeting. Patients provided consent to participate in MDTm and for data collection. Data were retrospectively extracted from MDTm reports. To evaluate the usefulness of the MDTm and the satisfaction of the participants, a survey was sent by email at least 3 months after the MDTm to the participants.

RESULTS

A total of 216 chILD cases were discussed during 56 MDTm sessions. The median age of onset was 0.5 years (interquartile range 0-7). The MDTm sessions resulted in the correction of chILD etiology in 25% of cases (neuroendocrine cell hyperplasia of infancy 17%, surfactant metabolism disorder 8%, pulmonary alveolar proteinosis 4%, hemosiderosis 3%, sarcoidosis 3%, and others 34%), and chILD was ruled out in 7% of cases. A change in therapy was proposed for 46% of cases. User satisfaction was significant, particularly regarding their confidence in managing these rare diseases.

DISCUSSION AND CONCLUSION

Dedicated MDTm sessions offer a unique opportunity to enhance chILD etiologic diagnosis and management, leading to increased physician knowledge and confidence in managing these patients.

Estimating the effect of nintedanib on forced vital capacity in children and adolescents with fibrosing interstitial lung disease using a Bayesian dynamic borrowing approach

BACKGROUND

The rarity of childhood interstitial lung disease (chILD) makes it challenging to conduct powered trials. In the InPedILD trial, among 39 children and adolescents with fibrosing ILD, there was a numerical benefit of nintedanib versus placebo on change in forced vital capacity (FVC) over 24 weeks (difference in mean change in FVC % predicted of 1.21 [95% confidence interval: -3.40, 5.81]). Nintedanib has shown a consistent effect on FVC across populations of adults with different diagnoses of fibrosing ILD.

METHODS

In a Bayesian dynamic borrowing analysis, prespecified before data unblinding, we incorporated data on the effect of nintedanib in adults and the data from the InPedILD trial to estimate the effect of nintedanib on FVC in children and adolescents with fibrosing ILD. The data from adults were represented as a meta-analytic predictive (MAP) prior distribution with mean 1.69 (95% credible interval: 0.49, 3.08). The adult data were weighted according to expert judgment on their relevance to the efficacy of nintedanib in chILD, obtained in a formal elicitation exercise.

RESULTS

Combined data from the MAP prior and InPedILD trial analyzed within the Bayesian framework resulted in a median difference between nintedanib and placebo in change in FVC % predicted at Week 24 of 1.63 (95% credible interval: -0.69, 3.40). The posterior probability for superiority of nintedanib versus placebo was 95.5%, reaching the predefined success criterion of at least 90%.

CONCLUSION

These findings, together with the safety data from the InPedILD trial, support the use of nintedanib in children and adolescents with fibrosing ILDs.

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.

Lung transplantation in children

Lung transplantation is a well-established treatment for children facing advanced lung disease and pulmonary vascular disorders. However, organ shortage remains highest in children. For fitting the small chest of children, transplantation of downsized adult lungs, lobes, or even segments were successfully established. The worldwide median survival after pediatric lung transplantation is currently 5.7 years, while under consideration of age, underlying disease, and peri- and posttransplant center experience, median survival of more than 10 years is reported. Timing of referral for transplantation, ischemia-reperfusion injury, primary graft dysfunction, and acute and chronic rejection after transplantation remain the main challenges.

Emerging Treatments for Childhood Interstitial Lung Disease

Childhood interstitial lung disease (chILD) is a large and heterogeneous group of disorders characterized by diffuse lung parenchymal markings on chest imaging and clinical signs such as dyspnea and hypoxemia from functional impairment. While some children already present in the neonatal period with interstitial lung disease (ILD), others develop ILD during their childhood and adolescence. A timely and accurate diagnosis is essential to gauge treatment and improve prognosis. Supportive care can reduce symptoms and positively influence patients' quality of life; however, there is no cure for many of the chILDs. Current therapeutic options include anti-inflammatory or immunosuppressive drugs. Due to the rarity of the conditions and paucity of research in this field, most treatments are empirical and based on case series, and less than a handful of small, randomized trials have been conducted thus far. A trial on hydroxychloroquine yielded good safety but a much smaller effect size than anticipated. A trial in fibrotic disease with the multitargeted tyrosine kinase inhibitor nintedanib showed similar pharmacokinetics and safety as in adults. The unmet need for the treatment of chILDs remains high. This article summarizes current treatments and explores potential therapeutic options for patients suffering from chILD.

Neonatal and Infant Lung Disorders: Glossary, Practical Approach, and Diagnoses

A multitude of lung disorders ranging from congenital and genetic anomalies to iatrogenic complications can affect the neonate or the infant within the first year of life. Neonatal and infant chest imaging, predominantly by plain radiography and computed tomography, is frequently employed to aid in diagnosis and management; however, these disorders can be challenging to differentiate due to their broad-ranging, and frequently overlapping radiographic features. A systematic and practical approach to imaging interpretation which includes recognition of radiologic patterns, utilization of commonly accepted nomenclature and classification, as well as interpretation of imaging findings in conjunction with clinical history can not only assist radiologists to suggest the diagnosis, but also aid clinicians in management planning. The contents of this article were endorsed by the leadership of both the World Federation of Pediatric Imaging (WFPI), and the International Society of Pediatric Thoracic Imaging (ISPTI).

Hyperoxic ventilatory response in infants is related to nocturnal hypoxaemia

Background

The carotid bodies primarily serve as oxaemia sensors that affect tidal breathing. Their function has not yet been studied in infants with nocturnal hypoxaemia. This cross-sectional study aimed to characterise the hyperoxic ventilatory response (HVR) in infants and its relationship to nocturnal hypoxaemia.

Methods

The HVR was analysed in term infants aged <24 months with childhood interstitial lung disease (chILD), those with severe recurrent wheezing (wheeze), and nonrespiratory controls. The HVR timing was characterised using hyperoxia response time (HRT1), and HVR magnitude was characterised by the relative change in minute volume between normoxia and 30-s hyperoxia (VE_dH30). Time spent with an arterial haemoglobin oxygen saturation (SpO2) <90% during overnight monitoring (t90) was estimated.

Results

HVR data were available for 23 infants with chILD, 24 wheeze and 14 control infants. A significant decrease in minute volume under 30 s of hyperoxia was observed in all patients. HRT1 was shorter in chILD (5.6±1.2 s) and wheeze (5.9±1.5 s) groups than in the controls (12.6±5.5 s) (ANOVA p<0.001). VE_dH30 was increased in the chILD group (24.3±8.0%) compared with that in the controls (14.7±9.2%) (p=0.003). t90 was abnormal in the wheeze (8.0±5.0%) and chILD (32.7±25.8%) groups and higher in the chILD group than in the controls (p<0.001). HRT1 negatively correlated with t90 in all groups.

Conclusion

Significant differences in HVR timing and magnitude were noted in the chILD, wheeze and control groups. A relationship between nocturnal hypoxaemia and HRT1 was proposed. HVR characterisation may help identify patients with abnormal nocturnal SpO2.

Childhood interstitial lung disease in Turkey: first data from the national registry

The childhood interstitial lung diseases (chILD) Turkey registry (chILD-TR) was established in November 2021 to increase awareness of disease, and in collaboration with the centers to improve the diagnostic and treatment standards. Here, the first results of the chILD registry system were presented. In this prospective cohort study, data were collected using a data-entry software system. The demographic characteristics, clinical, laboratory, radiologic findings, diagnoses, and treatment characteristics of the patients were evaluated. Clinical characteristics were compared between two main chILD groups ((A) diffuse parenchymal lung diseases (DPLD) disorders manifesting primarily in infancy [group1] and (B) DPLD disorders occurring at all ages [group 2]). There were 416 patients registered from 19 centers. Forty-six patients were excluded due to missing information. The median age of diagnosis of the patients was 6.05 (1.3-11.6) years. Across the study population (n = 370), 81 (21.8%) were in group 1, and 289 (78.1%) were in group 2. The median weight z-score was significantly lower in group 1 (- 2.0 [- 3.36 to - 0.81]) than in group 2 (- 0.80 [- 1.7 to 0.20]) (p < 0.001). When we compared the groups according to chest CT findings, ground-glass opacities were significantly more common in group 1, and nodular opacities, bronchiectasis, mosaic perfusion, and mediastinal lymphadenopathy were significantly more common in group 2. Out of the overall study population, 67.8% were undergoing some form of treatment. The use of oral steroids was significantly higher in group 2 than in group 1 (40.6% vs. 23.3%, respectively; p = 0.040).   Conclusion: This study showed that national registry allowed to obtain information about the frequency, types, and treatment methods of chILD in Turkey and helped to see the difficulties in the diagnosis and management of these patients. What is Known: • Childhood interstitial lung diseases comprise many diverse entities which are challenging to diagnose and manage. What is New: • This study showed that national registry allowed to obtain information about the frequency, types and treatment methods of chILD in Turkey and helped to see the difficulties in the diagnosis and management of these patients. Also, our findings reveal that nutrition should be considered in all patients with chILD, especially in A-DPLD disorders manifesting primarily in infancy.

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.

Unclassifiable interstitial lung disease and autoimmunity: Towards IPAF in children?

INTRODUCTION

Interstitial pneumonia with autoimmune features (IPAF) has been defined for adults with interstitial lung disease (ILD) and autoimmunity who do not meet the criteria for a specific connective tissue disease (CTD). We aimed to determine whether IPAF criteria could apply to children.

METHODS

We retrospectively studied patients with ILD and autoimmunity followed at Necker Hospital between 2008 and 2019. Children were classified according to specific CTD and IPAF criteria. The epidemiology and course of the disease were studied according to the final diagnosis.

RESULTS

Among 27 patients, 6 fulfilled the criteria for IPAF and represented 4.5% of all patients with ILD during the study period. Other diagnoses included juvenile dermatomyositis (30%), overlap syndromes (19%), systemic lupus erythematosus (15%), systemic sclerosis (7%), mixed CTD (4%), and rheumatoid arthritis (4%). IPAF patients were more frequently boys versus CTD-ILD patients (67% vs. 14%, p = .02). Two patients had severe respiratory distress that led to death for one of them. The course was favorable for the others, with a good response to steroids. The course tended to be more favorable for IPAF patients than for those with CTD-ILD (0% lung fibrosis in the IPAF group vs. 43% in the CTD-ILD group, p = .07).

CONCLUSION

We confirmed the existence of IPAF in children. Its prevalence was lower than in adults but comparable to that found for other pediatric series. Boys were more highly represented than in CTD-ILD. The course was favorable for most cases. Larger and more prospective studies are needed to confirm these results.

13-Year-Old Female With New Onset Multifocal Pulmonary Ground-Glass Opacities

A 13-year-old female who recently emigrated from Honduras presented to an emergency department in Texas with a 2-month history of weight loss, fatigue, cough, and progressive shortness of breath. Her symptoms started with a nonproductive cough, and she later developed dyspnea on exertion and orthopnea. On physical examination, she was tachycardic and tachypneic. She had a thin, emaciated body habitus. She was visibly in respiratory distress with nasal flaring, tracheal tugging, and intercostal and subcostal retractions. She had diminished breath sounds at the bases and bibasilar crackles. A computed tomography scan of the chest revealed multifocal ground-glass opacities throughout all lobes of both lungs with small bilateral pleural effusions and prominent bilateral hilar lymph nodes. We will discuss the approach to the initial evaluation and subsequent diagnosis.

Clinical features and outcomes of children's interstitial lung disease accompanied with connective tissue disease: A prospective cohort study

BACKGROUND

Medical complexity of childhood interstitial lung disease (chILD) with connective tissue disease (CTD) poses a considerable challenge to pediatricians.

METHODS

Clinical characteristics, laboratory findings, pulmonary function tests (PFTs), treatments and outcomes obtained for patients with CTD-chILD were analyzed in a prospective study.

RESULTS

Patients' median age at diagnosis was 7 years old. About 29.4% (15/51) suffered rapidly progressive childhood ILD (RP-chILD) with a high mortality rate (33.3%, 5/15), and the incidence of RP-chILD in juvenile idiopathic inflammatory myopathies was as high as 41.6% and the mortality rate was 30% (3/10). More than 70% patients had decreased diffusion capacity. The mean interval from symptoms-onset to diagnosis was 11.3 months. Compared to chILD with known CTD, the chILD proceeded CTD had a longer diagnosis interval, higher mortality, hospital stays and costs (P < 0.05). Lung imaging (33.3%) and lung function (72.7%) were partially reversible. The average survival time was 68.6 months. Cox univariate analysis showed that HRCT score ≥3, experiencing RP-chILD, cyanosis, acute respiratory distress syndrome (ARDS) and CD4 T cell <200 were significant predictors of death for chILD, whereas Cox multivariate analysis showed that ARDS was significant predictor of death for CTD-chILD, while IVIG support combined with corticosteroids and immunosuppressants was a protective factor.

CONCLUSIONS

Care providers should conduct an assessment for CTD in chILD as a longer interval between the diagnosis of chILD and the CTD is associated with increased mortality. Complications as ARDS predict poor outcome in CTD-chILD, while IVIG support combined with corticosteroids and immunosuppressants is a protective factor.

Genetics of bronchopulmonary dysplasia: An update

Bronchopulmonary dysplasia (BPD) is a multi-factorial disease that results from multiple clinical factors, including lung immaturity, mechanical ventilation, oxidative stress, pulmonary congestion due to increasing cardiac blood shunting, nutritional and immunological factors. Twin studies have indicated that susceptibility to BPD can be strongly inherited in some settings. Studies have reported associations between common genetic variants and BPD in preterm infants. Recent genomic studies have highlighted a potential role for molecular pathways involved in inflammation and lung development in affected infants. Rare mutations in genes encoding the lipid transporter ATP-binding cassette, sub-family A, member 3 (ABCA3 gene) which is involved in surfactant synthesis in alveolar type II cells, as well as surfactant protein B (SFTPB) and C (SFTPC) can also result in severe form of neonatal-onset interstitial lung diseases and may also potentially affect the course of BPD. This chapter summarizes the current state of knowledge on the genetics of BPD.

Single Cell Multiomics Identifies Cells and Genetic Networks Underlying Alveolar Capillary Dysplasia

Rationale: Alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) is a lethal developmental disorder of lung morphogenesis caused by insufficiency of FOXF1 (forkhead box F1) transcription factor function. The cellular and transcriptional mechanisms by which FOXF1 deficiency disrupts human lung formation are unknown. Objectives: To identify cell types, gene networks, and cell-cell interactions underlying the pathogenesis of ACDMPV. Methods: We used single-nucleus RNA and assay for transposase-accessible chromatin sequencing, immunofluorescence confocal microscopy, and RNA in situ hybridization to identify cell types and molecular networks influenced by FOXF1 in ACDMPV lungs. Measurements and Main Results: Pathogenic single-nucleotide variants and copy-number variant deletions involving the FOXF1 gene locus in all subjects with ACDMPV (n = 6) were accompanied by marked changes in lung structure, including deficient alveolar development and a paucity of pulmonary microvasculature. Single-nucleus RNA and assay for transposase-accessible chromatin sequencing identified alterations in cell number and gene expression in endothelial cells (ECs), pericytes, fibroblasts, and epithelial cells in ACDMPV lungs. Distinct cell-autonomous roles for FOXF1 in capillary ECs and pericytes were identified. Pathogenic variants involving the FOXF1 gene locus disrupt gene expression in EC progenitors, inhibiting the differentiation or survival of capillary 2 ECs and cell-cell interactions necessary for both pulmonary vasculogenesis and alveolar type 1 cell differentiation. Loss of the pulmonary microvasculature was associated with increased VEGFA (vascular endothelial growth factor A) signaling and marked expansion of systemic bronchial ECs expressing COL15A1 (collagen type XV α 1 chain). Conclusions: Distinct FOXF1 gene regulatory networks were identified in subsets of pulmonary endothelial and fibroblast progenitors, providing both cellular and molecular targets for the development of therapies for ACDMPV and other diffuse lung diseases of infancy.

[Highlights 56th SEPAR Congress]

The Spanish Society of Pneumology and Thoracic Surgery (SEPAR) has held its 56th congress in Granada from 8 to 10 June 2023. The SEPAR congress has established itself as the leading scientific meeting for specialists in medicine and respiratory care, reaching a record of participation this year with 2600 attendees. Our society thus demonstrates its leadership in the management of respiratory diseases, as well as its growth and progress in order to achieve excellence. In this review, we offer a summary of some notable issues addressed in six selected areas of interest: chronic obstructive pulmonary disease (COPD), asthma, interstitial lung diseases (ILDs), tuberculosis and respiratory infections, pulmonary circulation, and respiratory nursing.

Lung biopsy in infants with severe bronchopulmonary dysplasia

INTRODUCTION

Lung biopsy is infrequently performed in the population of infants with severe bronchopulmonary dysplasia (BPD). Yet, its presentation may overlap with other infant diffuse lung diseases, including those within the spectrum of childhood interstitial lung diseases (chILD). Lung biopsy might differentiate between these entities or identify those with an extremely poor prognosis. Both might alter the clinical management of some infants diagnosed with BPD.

METHODS

In this tertiary referral center, we drew on a retrospective cohort of 308 preterm infants with severe BPD. Of these, nine underwent lung biopsy between 2012 and 2017. We aimed to assess the indication for lung biopsy, the prior clinical history, safety of the procedure, and describe the biopsy findings. Finally, we considered management decisions in relation to the biopsy results in these patients.

RESULTS

All nine infants undergoing biopsy survived the procedure. The mean gestational age and birth weight of the nine patients were 30 ± 3 (range 27-34) weeks and 1421 ± 571 (range 611-2140) grams. All infants received serial echocardiograms to assess pulmonary hypertension, genetic testing, and computed tomography angiography (CTA) before biopsy. In all nine patients moderate to severe alveolar simplification was present and eight had some degree of pulmonary interstitial glycogenosis (PIG) ranging from focal to diffuse. Following biopsy, two infants with PIG received high dose systemic steroids and two separate infants had care redirected.

CONCLUSION

In our cohort, lung biopsy was safe and well tolerated. Findings from lung biopsy may aid decision making in selected patients as a part of a step-wise diagnostic algorithm.

Children's interstitial lung disease: Multidetector computed tomography patterns and correlations between imaging and histopathology

PURPOSE

Childhood interstitial lung disease (chILD) is an umbrella concept covering a wide range of rare lung diseases, many of which are unique to childhood. The diagnosis is based on clinical presentation, multidetector computed tomography (MDCT), genetic testing, lung-function testing, and lung biopsy. Because knowledge of the usefulness of MDCT pattern recognition in ChILD is at present limited, we examined the occurrence of MDCT patterns in children with histologically confirmed interstitial lung disease.

METHOD

We searched the biopsy, MDCT, and clinical information database of a single national paediatric referral hospital for 2004-2020. Data were from affected children under age 18. MDCT images we reanalysed while blinded to the identity and referral information.

RESULTS

We included 90 patients, of whom 63 (70 %) were male. The median age at biopsy was 1.3 years (interquartile range 0.1-16.8). Biopsy findings fell into 26 histological classes covering all nine chILD classification categories. We recognized six distinct MDCT patterns: neuroendocrine cell hyperplasia of infancy (23), organizing pneumonia (5), non-specific interstitial pneumonia (4), bronchiolitis obliterans (3), pulmonary alveolar proteinosis (2), and bronchopulmonary dysplasia (n = 2). Of the total 90, in 51 (57 %) children, none of these six MDCT patterns appeared. Of those 39 children with a recognizable MDCT pattern, in 34 (87 %), that pattern predicted their final diagnosis.

CONCLUSIONS

Among cases of chILD, we identified a specific predefined MDCT pattern in only 43 %. However, when such a recognizable pattern occurred, it was predictive of the final chILD diagnosis.

Mucopolysaccharidosis Type I Presenting with Persistent Neonatal Respiratory Distress: A Case Report

Mucopolysaccharidosis type I (MPS I) is a rare inherited autosomal recessive lysosomal storage disorder. Despite several reports on MPS I-related neonatal interstitial lung disease, it is still considered to be an under-recognized disease manifestation. Thus, further study of MPS I is required to improve specific therapies and management strategies. The current report describes a late preterm baby (36 weeks gestational age) with neonatal onset of interstitial lung disease eventually diagnosed as MPS I. The neonate required prolonged respiratory support and oxygen supplementation that further escalated the likely diagnosis of inherited disorders of pulmonary surfactant dysfunction. Whole-exome sequencing confirmed the diagnosis of MPS I, following the observation of low levels of the enzyme α-L-iduronidase. The results highlight the necessity of considering MPS I-related pulmonary involvement in newborns with persistent respiratory insufficiency.

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.

European Respiratory Society statement on familial pulmonary fibrosis

Genetic predisposition to pulmonary fibrosis has been confirmed by the discovery of several gene mutations that cause pulmonary fibrosis. Although genetic sequencing of familial pulmonary fibrosis (FPF) cases is embedded in routine clinical practice in several countries, many centres have yet to incorporate genetic sequencing within interstitial lung disease (ILD) services and proper international consensus has not yet been established. An international and multidisciplinary expert Task Force (pulmonologists, geneticists, paediatrician, pathologist, genetic counsellor, patient representative and librarian) reviewed the literature between 1945 and 2022, and reached consensus for all of the following questions: 1) Which patients may benefit from genetic sequencing and clinical counselling? 2) What is known of the natural history of FPF? 3) Which genes are usually tested? 4) What is the evidence for telomere length measurement? 5) What is the role of common genetic variants (polymorphisms) in the diagnostic workup? 6) What are the optimal treatment options for FPF? 7) Which family members are eligible for genetic sequencing? 8) Which clinical screening and follow-up parameters may be considered in family members? Through a robust review of the literature, the Task Force offers a statement on genetic sequencing, clinical management and screening of patients with FPF and their relatives. This proposal may serve as a basis for a prospective evaluation and future international recommendations.

Diagnostic workup of childhood interstitial lung disease

Childhood interstitial lung diseases (chILDs) are rare and heterogeneous diseases with significant morbidity and mortality. An accurate and quick aetiological diagnosis may contribute to better management and personalised treatment. On behalf of the European Respiratory Society Clinical Research Collaboration for chILD (ERS CRC chILD-EU), this review summarises the roles of the general paediatrician, paediatric pulmonologists and expert centres in the complex diagnostic workup. Each patient's aetiological chILD diagnosis must be reached without prolonged delays in a stepwise approach from medical history, signs, symptoms, clinical tests and imaging, to advanced genetic analysis and specialised procedures including bronchoalveolar lavage and biopsy, if necessary. Finally, as medical progress is fast, the need to revisit a diagnosis of "undefined chILD" is stressed.

ABCA3

BACKGROUND

The majority of patients with childhood interstitial lung disease (chILD) caused by pathogenic variants in ATP binding cassette subfamily A member 3 (ABCA3) develop severe respiratory insufficiency within their first year of life and succumb to disease if not lung transplanted. This register-based cohort study reviews patients with ABCA3 lung disease who survived beyond the age of 1 year.

METHOD

Over a 21-year period, patients diagnosed as chILD due to ABCA3 deficiency were identified from the Kids Lung Register database. 44 patients survived beyond the first year of life and their long-term clinical course, oxygen supplementation and pulmonary function were reviewed. Chest CT and histopathology were scored blindly.

RESULTS

At the end of the observation period, median age was 6.3 years (IQR: 2.8-11.7) and 36/44 (82%) were still alive without transplantation. Patients who had never received supplemental oxygen therapy survived longer than those persistently required oxygen supplementation (9.7 (95% CI 6.7 to 27.7) vs 3.0 years (95% CI 1.5 to 5.0), p=0.0126). Interstitial lung disease was clearly progressive over time based on lung function (forced vital capacity % predicted absolute loss -1.1% /year) and on chest CT (increasing cystic lesions in those with repetitive imaging). Lung histology pattern were variable (chronic pneumonitis of infancy, non-specific interstitial pneumonia, and desquamative interstitial pneumonia). In 37/44 subjects, the ABCA3 sequence variants were missense variants, small insertions or deletions with in-silico tools predicting some residual ABCA3 transporter function.

CONCLUSION

The natural history of ABCA3-related interstitial lung disease progresses during childhood and adolescence. Disease-modifying treatments are desirable to delay such disease course.

Novel technique of performing transbronchial lung cryobiopsy (TBLC) for diagnosing diffuse parenchymal lung diseases (DPLD) in infants

Childhood interstitial lung disease (ChILD) diagnosis often requires surgical lung biopsy after the common causes are ruled out. However, surgical lung biopsy has its own set of complications. Hence transbronchial lung cryobiopsy has been used in various studies of adult interstitial lung disease (ILD) with good yield and minimal complications. But this newer mode is rarely used in diagnosing children with suspected ILD. Here, we present the first case of the use of this technique in an infant via a rigid tracheoscope.

Inherited pulmonary surfactant metabolism disorders in Argentina: Differences between patients with SFTPC and ABCA3 variants

BACKGROUND

Patients with inherited pulmonary surfactant metabolism disorders have a wide range of clinical outcomes and imaging findings. Response to current anti-inflammatory therapies has been variable and efficacy is unclear.

OBJECTIVE

To describe and compare genetic, clinical, histological, and computed tomography (CT) outcomes in a cohort of patients with variants in the genes encoding surfactant protein C (SP-C) or adenosine triphosphate-binding cassette transporter A3 (ABCA3) in Argentina.

METHODS

Observational cohort retrospective study. Patients carrying variants in genes encoding SP-C and ABCA3 proteins were included.

RESULTS

Fourteen patients met the inclusion criteria: SFTPC n = 6, ABCA3 n = 8 (seven were heterozygous and one compound heterozygous). Neonatal respiratory distress was more frequent and severe in neonates with variants in the ABCA3 gene. The onset of the disease occurred in infancy before the age of 20 months in all cases. Patients with ABCA3 pathogenic variants had a severe clinical course, while long-term outcomes were more favorable in individuals with SFTPC variants. Initial CT findings were ground glass opacities and intraparenchymal cysts in both groups. Over time, signs of lung fibrosis were present in 57% of patients with ABCA3 variants and in 33% of the SFTPC group. The efficacy of anti-inflammatory interventions appears to be poor, especially for patients with ABCA3 pathogenic variants.

CONCLUSIONS

Clinical, histological, and radiological features are similar in patients with SFTPC and ABCA3 variants; however, the latter have more severe clinical course. Current anti-inflammatory regimens do not appear to stop the progression of the disease.