Ten-year experience of whole lung lavage in pediatric Pulmonary Alveolar Proteinosis.

BACKGROUND: Pulmonary Alveolar Proteinosis (PAP) is extremely rare and can be caused by hereditary dysfunction of the granulocyte macrophage colony-stimulating factor receptor (GM-CSF) receptor, autoantibodies against GM-CSF, or other diseases leading to alveolar macrophage (AM) dysfunction. This leads to protein accumulation in the lung and severe dyspnea and hypoxemia. Whole lung lavage (WLL) is the first line treatment strategy. METHODS: Here, we present data from more than ten years of WLL practice in pediatric PAP. WLL performed by the use of a single lumen or double lumen tube (SLT vs. DLT) were compared for technical features, procedure time, and adverse events. RESULTS: A total of n=57 procedures in six PAP patients between 3.5 and 14.3 years of age were performed. SLT based WLL in smaller children was associated with comparable rates of adverse events but with longer intervention times and postprocedural intensive care treatment when compared to DLT based procedures. DISCUSSION: Our data shows that WLL is feasible even in small children. DLT based WLL seems to be more effective, and our data supports the notion that it should be considered as early as possible in pediatric PAP. CONCLUSION: WLL lavage is possible in small PAP patients but should performed in close interdisciplinary cooperation and with age appropriate protocols.

Bilateral lung transplantation for pediatric pulmonary arterial hypertension: perioperative management and one-year follow-up.

Background: Bilateral lung transplantation (LuTx) remains the only established treatment for children with end-stage pulmonary arterial hypertension (PAH). Although PAH is the second most common indication for LuTx, little is known about optimal perioperative management and midterm clinical outcomes. Methods: Prospective observational study on consecutive children with PAH who underwent LuTx with scheduled postoperative VA-ECMO support at Hannover Medical School from December 2013 to June 2020. Results: Twelve patients with PAH underwent LuTx (mean age 11.9 years; age range 1.9-17.8). Underlying diagnoses included idiopathic (n = 4) or heritable PAH (n = 4), PAH associated with congenital heart disease (n = 2), pulmonary veno-occlusive disease (n = 1), and pulmonary capillary hemangiomatosis (n = 1). The mean waiting time was 58.5 days (range 1-220d). Three patients were bridged to LuTx on VA-ECMO. Intraoperative VA-ECMO/cardiopulmonary bypass was applied and VA-ECMO was continued postoperatively in all patients (mean ECMO-duration 185 h; range 73-363 h; early extubation). The median postoperative ventilation time was 28 h (range 17-145 h). Echocardiographic conventional and strain analysis showed that 12 months after LuTx, all patients had normal biventricular systolic function. All PAH patients are alive 2 years after LuTx (median follow-up 53 months, range 26-104 months). Conclusion: LuTx in children with end-stage PAH resulted in excellent midterm outcomes (100% survival 2 years post-LuTx). Postoperative VA-ECMO facilitates early extubation with rapid gain of allograft function and sustained biventricular reverse-remodeling and systolic function after RV pressure unloading and LV volume loading.

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-related interstitial lung disease beyond infancy.

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.

Unusual phenotypes in patients with a pathogenic germline variant in DICER1.

Pathogenic germline DICER1 variants are associated with pleuropulmonary blastoma, multinodular goiter, embryonal rhabdomyosarcoma and other tumour types, while mosaic missense DICER1 variants in the RNase IIIb domain are linked to cause GLOW (global developmental delay, lung cysts, overgrowth, and Wilms' tumor) syndrome. Here, we report four families with germline DICER1 pathogenic variants in which one member in each family had a more complex phenotype, including skeletal findings, facial dysmorphism and developmental abnormalities. The developmental features occur with a variable expressivity and incomplete penetrance as also described for the neoplastic and dysplastic lesions associated with DICER1 variants. Whole exome sequencing (WES) was performed on all four cases and revealed no further pathogenic or likely pathogenic dominant, homozygous or compound heterozygous variants in three of them. Notably, a frameshift variant in ARID1B was detected in one patient explaining part of her phenotype. This series of patients shows that pathogenic DICER1 variants may be associated with a broader phenotypic spectrum than initially assumed, including predisposition to different tumours, skeletal findings, dysmorphism and developmental abnormalities, but genetic work up in syndromic patients should be comprehensive in order not to miss additional underlying /modifying causes.

Interventional Bronchus Occlusion Using Amplatzer Devices - A Promising Treatment Option for Children with Persistent Air Leak.

BACKGROUND: Persistent air leak (PAL) is a severe complication of secondary spontaneous pneumothorax (SSP). Surgical interventions are usually successful when medical treatment fails, but can be associated with significant complications and loss of potentially recoverable lung parenchyma. METHODS: Retrospective analysis of efficacy and safety of interventional bronchus occlusions (IBO) using Amplatzer devices (ADs) in children with PAL secondary to SSP. RESULTS: Six patients (four males, 4-15 years of age) underwent IBO using ADs as treatment for PAL. Necrotizing pneumonia (NP) was the most common cause (n=4) of PAL. Three patients were previously healthy and three suffered from chronic lung disease. All patients required at least two chest tubes prior to the intervention for a duration of 15-43 days and all required oxygen or higher level of ventilatory support. In three cases, previous surgical interventions had been performed without success. All children improved after endobronchial intervention and we observed no associated complications. All chest tubes were removed within 5-25 days post IBO. In patients with PAL related to NP (n=4), occluders were removed bronchoscopically without re-occurrence of pneumothorax after a mean of 70 days (IQR: 46.5-94). CONCLUSION: IBO using ADs is a safe and valuable treatment option in children with PAL independent of disease severity and underlying cause. A major advantage of this procedure is its less invasiveness compared to surgery and the parenchyma- preserving approach.

Current Practices on Diagnosis, Prevention and Treatment of Post-Transplant Lymphoproliferative Disorder in Pediatric Patients after Solid Organ Transplantation: Results of ERN TransplantChild Healthcare Working Group Survey.

(1) Background: Post-transplant lymphoproliferative disease (PTLD) is a significant complication of solid organ transplantation (SOT). However, there is lack of consensus in PTLD management. Our aim was to establish a present benchmark for comparison between international centers and between various organ transplant systems and modalities; (2) Methods: A cross-sectional questionnaire of relevant PTLD practices in pediatric transplantation was sent to multidisciplinary teams from 17 European center members of ERN TransplantChild to evaluate the centers' approach strategies for diagnosis and treatment and how current practices impact a cross-sectional series of PTLD cases; (3) Results: A total of 34 SOT programs from 13 European centers participated. The decision to start preemptive treatment and its guidance was based on both EBV viremia monitoring plus additional laboratory methods and clinical assessment (61%). Among treatment modalities the most common initial practice at diagnosis was to reduce the immunosuppression (61%). A total of 126 PTLD cases were reported during the period 2012-2016. According to their histopathological classification, monomorphic lesions were the most frequent (46%). Graft rejection after PTLD remission was 33%. Of the total cases diagnosed with PTLD, 88% survived; (4) Conclusions: There is still no consensus on prevention and treatment of PTLD, which implies the need to generate evidence. This might successively allow the development of clinical guidelines.

Multiple breath washout quality control in the clinical setting.

BACKGROUND: Multiple breath washout (MBW) is increasingly used in the clinical assessment of patients with cystic fibrosis (CF). Guidelines for MBW quality control (QC) were developed primarily for retrospective assessment and central overreading. We assessed whether real-time QC of MBW data during the measurement improves test acceptability in the clinical setting. METHODS: We implemented standardized real-time QC and reporting of MBW data at the time of the measurement in the clinical pediatric lung function laboratory in Bern, Switzerland, in children with CF aged 4-18 years. We assessed MBW test acceptability before (31 tests; 89 trials) and after (32 tests; 96 trials) implementation of real-time QC and compared agreement between reviewers. Further, we assessed the implementation of real-time QC at a secondary center in Zurich, Switzerland. RESULTS: Before the implementation of real-time QC in Bern, only 58% of clinical MBW tests were deemed acceptable following retrospective QC by an experienced reviewer. After the implementation of real-time QC, MBW test acceptability improved to 75% in Bern. In Zurich, after the implementation of real-time QC, test acceptability improved from 38% to 70%. Further, the agreement between MBW operators and an experienced reviewer for test acceptability was 84% in Bern and 93% in Zurich. CONCLUSION: Real-time QC of MBW data at the time of measurement is feasible in the clinical setting and results in improved test acceptability.

Influenza A viruses limit NLRP3-NEK7-complex formation and pyroptosis in human macrophages.

Pyroptosis is a fulminant form of macrophage cell death, contributing to release of pro-inflammatory cytokines. In humans, it depends on caspase 1/4-activation of gasdermin D and is characterized by the release of cytoplasmic content. Pathogens apply strategies to avoid or antagonize this host response. We demonstrate here that a small accessory protein (PB1-F2) of contemporary H5N1 and H3N2 influenza A viruses (IAV) curtails fulminant cell death of infected human macrophages. Infection of macrophages with a PB1-F2-deficient mutant of a contemporary IAV resulted in higher levels of caspase-1 activation, cleavage of gasdermin D, and release of LDH and IL-1ß. Mechanistically, PB1-F2 limits transition of NLRP3 from its auto-repressed and closed confirmation into its active state. Consequently, interaction of a recently identified licensing kinase NEK7 with NLRP3 is diminished, which is required to initiate inflammasome assembly.

Pulmonary function testing in children's interstitial lung disease.

The use of pulmonary function tests (PFTs) has been widely described in airway diseases like asthma and cystic fibrosis, but for children's interstitial lung disease (chILD), which encompasses a broad spectrum of pathologies, the usefulness of PFTs is still undetermined, despite widespread use in adult interstitial lung disease. A literature review was initiated by the COST/Enter chILD working group aiming to describe published studies, to identify gaps in knowledge and to propose future research goals in regard to spirometry, whole-body plethysmography, infant and pre-school PFTs, measurement of diffusing capacity, multiple breath washout and cardiopulmonary exercise tests in chILD. The search revealed a limited number of papers published in the past three decades, of which the majority were descriptive and did not report pulmonary function as the main outcome.PFTs may be useful in different stages of management of children with suspected or confirmed chILD, but the chILD spectrum is diverse and includes a heterogeneous patient group in all ages. Research studies in well-defined patient cohorts are needed to establish which PFT and outcomes are most relevant for diagnosis, evaluation of disease severity and course, and monitoring individual conditions both for improvement in clinical care and as end-points in future randomised controlled trials.

An apple a day won't keep the doctor away: presentation, treatment, and outcome in pediatric apple aspirations.

INTRODUCTION: Foreign body (FB) aspiration is a frequent and preventable source of morbidity and mortality, especially in children under 4 years of age. Few comprehensive studies exist on presentation and outcome of apple aspirations in children. METHODS: In a retrospective analysis of bronchoscopy records of a tertiary medical care center from January 2007 to August 2019, we identified pediatric cases of suspected apple aspirations. RESULTS: A total of 11 suspected apple aspirations were identified (observation time 12.7 years, n = 5858 bronchoscopies, n = 226 interventions due to suspected FB aspirations in total). The mean age of patients was 24 months (standard error mean, 7 months; range, 8-83 months), and 6 out of 11 cases (55%) were male. Bronchoscopy confirmed apple aspiration in n = 6/11 cases (55%). In n = 2/11 cases (18%), a bite of the apple was located in the esophagus causing significant tracheal narrowing, and in n = 3/11 cases (27%), no FB was found. In all cases of airway FB identification, extraction was successful. Hypersalivation was associated with esophageal FB location, whereas persistent cough, stridor, or dyspnea were associated with airway FB location. Outcomes ranged from complete reconstitution 1 day after bronchoscopy in most cases to hypoxemia with severe brain damage in one patient. DISCUSSION: This analysis shows that apple aspirations are not entirely uncommon in children and may lead to disastrous complications. Typical signs of airway location are persistent cough, stridor or dyspnea, whereas hypersalivation may point toward an esophageal location. In each case of suspected apple aspiration, timely bronchoscopy with possible FB extraction should be performed by an experienced team.

Tuberculosis screening during the 2015 European refugee crisis.

BACKGROUND: The purpose of our study was to describe and evaluate management, performance and results of Tuberculosis (TB)-screening among refugees and asylum seekers in a rural area in Germany in 2015. METHODS: Refugees or asylum seekers, staying in shared-accommodation are obligated to participate on screening chest X-ray (CXR) in order to screen for signs of potentially infectious pulmonary TB (German Protection against Infection Act and German Asylum Procedure Act). n = 705 individuals underwent screening chest X-ray (CXR) to detect pulmonary TB in September and October 2015 on site. One experienced radiologist interpreted and reported each CXR within 24 h after the enrollment in the screening program and results were sent to the local Public Health Department for potential further medical care. Image abnormalities suggestive for TB were defined according to established radiographic criteria such as pleural effusion, cavitation, consolidation, fibrous scarring or calcification. Only in case of TB-suggestive findings on CXR, further diagnostics were arranged (pulmonological examination, follow-up CXR, sputum culture, interferon-gamma release assay, bronchoscopy). Follow-up data was collected in collaboration with the local Public Health Department. Descriptive statistics were calculated using GraphPad Prism software. RESULTS: n = 637 CXR examinations (90%) did not show abnormal findings, n = 54 CXR (8%) showed incidental findings, and n = 14 CXR (2%) were suspicious for acute TB. Of these, n = 14 individuals, eight underwent further TB diagnostics. Active TB was confirmed in one individual (0.001% of the screening cohort). CONCLUSIONS: Our cohort reflects current immigrations statistics in Europe and illustrates an overall low TB prevalence amongst individuals entering Germany in 2015. However, our findings support the improvement of diagnostic algorithms.

Complications and risk factors in pediatric bronchoscopy in a tertiary pediatric respiratory center.

Bronchoscopy is an established procedure routinely used by pediatric pulmonologists. Despite its frequent application, data on complications and specific risk factors are scarce and sometimes conflicting. AIM: The aim of this study was to evaluate frequency and severity of clearly defined complications of bronchoscopy in children that occur both during and after the procedure, and to identify potential risk factors. METHOD: A retrospective single-center analysis of 670 elective bronchoscopies in 522 children aged 0-17 years during the time period of 2008-2012 was performed. Procedures in intensive care unit patients and children after lung transplantation were excluded. RESULTS: Mean patient age was 5.58 years, 61.5% had underlying chronic diseases. Intraprocedural complications occurred in 7.2% of all procedures; of these, hypoxemia was the most common, occuring in 4.8% of cases. Postprocedural adverse events were documented in 25.8%, the most frequent of which were fever in 14.2% and transient oxygen dependency in 13.4% of cases. No bronchoscopy related deaths occurred. Multivariate logistic regression was used to identify risk factors for (1) any complication, or (2) severe complications. Age below two years (OR 1.837 [1.224-2.757], P = 0.003) and primary ciliary dyskinesia (OR 4.821 [2.018-11.552], P < 0.001) significantly contributed to risk of any complication. Age below 2 years (OR 2.478 [1.072-5.728], P = 0.034) and underlying cardiovascular disease (OR 2.678 [1.013-7.077], P = 0.047) were independent risk factors for severe complications. CONCLUSION: Bronchoscopy in children is relatively safe. Nevertheless, adverse events can occur and knowledge of risk factors may help prevent complications.