Impact of ambient air pollution on lung function in preterm-born school-aged children

RATIONALE

Increased outdoor air pollution worsens lung function in children. However, these associations are less well studied in preterm-born individuals.

OBJECTIVES

We assessed associations between ambient air pollutants and spirometry measures in preterm-born children.

METHODS

The Respiratory Health Outcomes in Neonates study recruited preterm-born children aged 7-12 years who were born at ≤34 week's gestation. We associated four ambient air pollutants (particulate matter with aerodynamic diameter ≤2.5 µm (PM2.5), PM10, nitrogen dioxide (NO2) and sulfur dioxide) at time of birth and spirometry assessment and averaged exposure between these two time points with spirometry measures, using linear regression analyses. Gestational age was banded into 23-28, 29-31 and 32-34 week's. Regression models estimated spirometry values against pollutant levels at birth and at the time of spirometry.

MEASUREMENTS AND MAIN RESULTS

From 565 preterm-born children, 542 (96%) had satisfactory data. After adjustments for early and current life factors, significant detrimental associations were noted between PM10 at birth and per cent predicted forced vital capacity (%FVC) for the 23-28 and 29-31 week's gestation groups and between current PM2.5 and NO2 exposure and %FVC for the 23-28 week's gestation group. No associations with spirometry were noted for the averaged pollution exposure between birth and spirometry. Predictive models showed 5.9% and 7.4% differences in %FVC between the highest and lowest current pollution exposures for PM2.5 and NO2, respectively, in the 23-28 week group.

CONCLUSIONS

Birth and current exposures to road-traffic-associated pollutants detrimentally affected %FVC in preterm-born school-aged children, who already have compromised lung function.

Erdosteine in children and adults with bronchiectasis (BETTER trial): study protocol for a multicentre, double-blind, randomised controlled trial

INTRODUCTION

Bronchiectasis is a worldwide chronic lung disorder where exacerbations are common. It affects people of all ages, but especially Indigenous populations in high-income nations. Despite being a major contributor to chronic lung disease, there are no licensed therapies for bronchiectasis and there remain relatively few randomised controlled trials (RCTs) conducted in children and adults. Our RCT will address some of these unmet needs by evaluating whether the novel mucoactive agent, erdosteine, has a therapeutic role in children and adults with bronchiectasis.Our primary aim is to determine in children and adults aged 2-49 years with bronchiectasis whether regular erdosteine over a 12-month period reduces acute respiratory exacerbations compared with placebo. Our primary hypothesis is that people with bronchiectasis who regularly use erdosteine will have fewer exacerbations than those receiving placebo.Our secondary aims are to determine the effect of the trial medications on quality of life (QoL) and other clinical outcomes (exacerbation duration, time-to-next exacerbation, hospitalisations, lung function, adverse events). We will also assess the cost-effectiveness of the intervention.

METHODS AND ANALYSIS

We are undertaking an international multicentre, double-blind, placebo-RCT to evaluate whether 12 months of erdosteine is beneficial for children and adults with bronchiectasis. We will recruit 194 children and adults with bronchiectasis to a parallel, superiority RCT at eight sites across Australia, Malaysia and Philippines. Our primary endpoint is the rate of exacerbations over 12 months. Our main secondary outcomes are QoL, exacerbation duration, time-to-next exacerbation, hospitalisations and lung function.

ETHICS AND DISSEMINATION

The Human Research Ethics Committees (HREC) of Children's Health Queensland (for all Australian sites), University of Malaya Medical Centre (Malaysia) and St. Luke's Medical Centre (Philippines) approved the study. We will publish the results and share the outcomes with the academic and medical community, funding and relevant patient organisations.

TRIAL REGISTRATION NUMBER

ACTRN12621000315819.

Prevalence of lung cysts in adolescents and adults with a germline DICER1 pathogenic/likely pathogenic variant: a report from the National Institutes of Health and International Pleuropulmonary Blastoma/DICER1 Registry

BACKGROUND

Pleuropulmonary blastoma (PPB), the hallmark tumour associated with DICER1-related tumour predisposition, is characterised by an age-related progression from a cystic lesion (type I) to a high-grade sarcoma with mixed cystic and solid features (type II) or purely solid lesion (type III). Not all cystic PPBs progress; type Ir (regressed), hypothesised to represent regressed or non-progressed type I PPB, is an air-filled, cystic lesion lacking a primitive sarcomatous component. This study aims to evaluate the prevalence of non-progressed lung cysts detected by CT scan in adolescents and adults with germline DICER1 pathogenic/likely pathogenic (P/LP) variants.

METHODS

Individuals were enrolled in the National Cancer Institute Natural History of DICER1 Syndrome study, the International PPB/DICER1 Registry and/or the International Ovarian and Testicular Stromal Tumor Registry. Individuals with a germline DICER1 P/LP variant with first chest CT at 12 years of age or older were selected for this analysis.

RESULTS

In the combined databases, 110 individuals with a germline DICER1 P/LP variant who underwent first chest CT at or after the age of 12 were identified. Cystic lung lesions were identified in 38% (42/110) with a total of 72 cystic lesions detected. No demographic differences were noted between those with lung cysts and those without lung cysts. Five cysts were resected with four centrally reviewed as type Ir PPB.

CONCLUSION

Lung cysts are common in adolescents and adults with germline DICER1 variation. Further study is needed to understand the mechanism of non-progression or regression of lung cysts in childhood to guide judicious intervention.

Automatic analysis of bronchus-artery dimensions to diagnose and monitor airways disease in cystic fibrosis

BACKGROUND

Cystic fibrosis (CF) lung disease is characterised by progressive airway wall thickening and widening. We aimed to validate an artificial intelligence-based algorithm to assess dimensions of all visible bronchus-artery (BA) pairs on chest CT scans from patients with CF.

METHODS

The algorithm fully automatically segments the bronchial tree; identifies bronchial generations; matches bronchi with the adjacent arteries; measures for each BA-pair bronchial outer diameter (Bout), bronchial lumen diameter (Bin), bronchial wall thickness (Bwt) and adjacent artery diameter (A); and computes Bout/A, Bin/A and Bwt/A for each BA pair from the segmental bronchi to the last visible generation. Three datasets were used to validate the automatic BA analysis. First BA analysis was executed on 23 manually annotated CT scans (11 CF, 12 control subjects) to compare automatic with manual BA-analysis outcomes. Furthermore, the BA analysis was executed on two longitudinal datasets (Copenhagen 111 CTs, ataluren 347 CTs) to assess longitudinal BA changes and compare them with manual scoring results.

RESULTS

The automatic and manual BA analysis showed no significant differences in quantifying bronchi. For the longitudinal datasets the automatic BA analysis detected 247 and 347 BA pairs/CT in the Copenhagen and ataluren dataset, respectively. A significant increase of 0.02 of Bout/A and Bin/A was detected for Copenhagen dataset over an interval of 2 years, and 0.03 of Bout/A and 0.02 of Bin/A for ataluren dataset over an interval of 48 weeks (all p<0.001). The progression of 0.01 of Bwt/A was detected only in the ataluren dataset (p<0.001). BA-analysis outcomes showed weak to strong correlations (correlation coefficient from 0.29 to 0.84) with manual scoring results for airway disease.

CONCLUSION

The BA analysis can fully automatically analyse a large number of BA pairs on chest CTs to detect and monitor progression of bronchial wall thickening and bronchial widening in patients with CF.

Lung function tracking in children with perinatally acquired HIV following early antiretroviral therapy initiation

INTRODUCTION

Lung disease remains a frequent complication in children with perinatal HIV infection (CHIV) and exposure without infection (CHEU), resulting in diminished lung function. In CHIV, early antiretroviral therapy (ART) initiation improves survival and extrapulmonary outcomes. However, it is unknown if there is benefit to lung function.

METHODS

Cohorts of CHIV (ART initiated at median 4.0 months), CHEU and HIV-unexposed children (CHU) prospectively performed pulmonary function testing (PFT) consisting of spirometry, plethysmography and diffusing capacity from 2013 to 2020. We determined lung function trajectories for PFT outcomes comparing CHIV to CHU and CHEU to CHU, using linear mixed effects models with multiple imputation. Potential confounders included sex, age, height, weight, body mass index z-score, urine cotinine and Tanner stage.

RESULTS

328 participants (122 CHIV, 126 CHEU, 80 CHU) performed PFT (ages 6.6-15.6 years). Spirometry (forced expiratory volume in 1 s, FEV1, forced vital capacity (FVC), FEV1/FVC) outcomes were similar between groups. In plethysmography, the mean residual volume (RV) z-score was 17% greater in CHIV than CHU (95% CI 1% to 33%, p=0.042). There was no difference in total lung capacity (TLC) or RV/TLC z-scores between groups. Diffusing capacity for carbon monoxide was similar in all groups, while alveolar volume (VA) differed between HIV groups by sex.

CONCLUSION

Our study indicates that early ART initiation can mitigate the loss of lung function in CHIV with lasting benefit through childhood; however, there remains concern of small airway disease. CHEU does not appear to disrupt childhood lung function trajectory.

Risk factors for poorer respiratory outcomes in adolescents and young adults born preterm

RATIONALE

The respiratory outcomes for adult survivors of preterm birth in the postsurfactant era are wide-ranging with prognostic factors, especially those encountered after the neonatal period, poorly understood.

OBJECTIVES

To obtain comprehensive 'peak' lung health data from survivors of very preterm birth and identify neonatal and life-course risk factors for poorer respiratory outcomes in adulthood.

METHODS

127 participants born ≤32 weeks gestation (64%, n=81 with bronchopulmonary dysplasia (BPD), initially recruited according to a 2 with-BPD:1 without-BPD strategy), and 41 term-born controls completed a lung health assessment at 16-23 years, including lung function, imaging and symptom review. Risk factors assessed against poor lung health included neonatal treatments, respiratory hospitalisation in childhood, atopy and tobacco smoke exposure.

MEASUREMENTS AND MAIN RESULTS

Young adults born prematurely had greater airflow obstruction, gas trapping and ventilation inhomogeneity, in addition to abnormalities in gas transfer and respiratory mechanics, compared with term. Beyond lung function, we observed greater structural abnormalities, respiratory symptoms and inhaled medication use. A previous respiratory admission was associated with airway obstruction; mean forced expiratory volume in 1 s/forced vital capacity z-score was -0.561 lower after neonatal confounders were accounted for (95% CI -0.998 to -0.125; p=0.012). Similarly, respiratory symptom burden was increased in the preterm group with a respiratory admission, as was peribronchial thickening (6% vs 23%, p=0.010) and bronchodilator responsiveness (17% vs 35%, p=0.025). Atopy, maternal asthma and tobacco smoke exposure did not influence lung function or structure at 16-23 years in our preterm cohort.

CONCLUSIONS

Even after accounting for the neonatal course, a respiratory admission during childhood remained significantly associated with reduced peak lung function in the preterm-born cohort, with the largest difference seen in those with BPD. A respiratory admission during childhood should, therefore, be considered a risk factor for long-term respiratory morbidity in those born preterm, especially for individuals with BPD.

Acute respiratory failure-related excess mortality in pediatric sepsis

Excess mortality risk imparted by acute respiratory failure in children is unknown. We determined excess mortality risk associated with mechanically ventilated acute respiratory failure in pediatric sepsis. Novel ICD10-based algorithms were derived and validated to identify a surrogate for acute respiratory distress syndrome to calculate excess mortality risk. Algorithm-identified ARDS was identified with specificity of 96.7% (CI 93.0 - 98.9) and sensitivity of 70.5% (CI 44.0 - 89.7). Excess risk of mortality for ARDS was 24.4% (CI 22.9 - 26.2). Development of ARDS requiring mechanical ventilation imparts modest excess risk of mortality in septic children.

Tracheostomy in children is associated with neutrophilic airway inflammation

BACKGROUND

Tracheostomies in children are associated with significant morbidity, poor quality of life, excess healthcare costs and excess mortality. The underlying mechanisms facilitating adverse respiratory outcomes in tracheostomised children are poorly understood. We aimed to characterise airway host defence in tracheostomised children using serial molecular analyses.

METHODS

Tracheal aspirates, tracheal cytology brushings and nasal swabs were prospectively collected from children with a tracheostomy and controls. Transcriptomic, proteomic and metabolomic methods were applied to characterise the impact of tracheostomy on host immune response and the airway microbiome.

RESULTS

Children followed up serially from the time of tracheostomy up to 3 months postprocedure (n=9) were studied. A further cohort of children with a long-term tracheostomy were also enrolled (n=24). Controls (n=13) comprised children without a tracheostomy undergoing bronchoscopy. Long-term tracheostomy was associated with airway neutrophilic inflammation, superoxide production and evidence of proteolysis when compared with controls. Reduced airway microbial diversity was established pre-tracheostomy and sustained thereafter.

CONCLUSIONS

Long-term childhood tracheostomy is associated with a inflammatory tracheal phenotype characterised by neutrophilic inflammation and the ongoing presence of potential respiratory pathogens. These findings suggest neutrophil recruitment and activation as potential exploratory targets in seeking to prevent recurrent airway complications in this vulnerable group of patients.

Surveillance towards preventing paediatric incidence of respiratory syncytial virus attributable respiratory tract infection in primary and secondary/tertiary healthcare settings in Merseyside, Cheshire and Bristol, UK

INTRODUCTION

Respiratory syncytial virus (RSV) is a common respiratory virus, particularly affecting children, and can cause respiratory infections such as croup and bronchiolitis. The latter is a leading cause of paediatric hospitalisation within the UK. Children <3 years of age and/or with underlying health conditions are more vulnerable to severe RSV infection.There are currently limited data on the incidence of laboratory-confirmed RSV, particularly within primary care settings and outside the typical 'RSV season', which in the Northern hemisphere tends to coincide with winter months. There is also a lack of data on the health economic impact of RSV infection on families and healthcare systems.This observational surveillance study aims to collect data on the incidence of laboratory-confirmed RSV-attributable respiratory tract infection (RTI) in children aged <3 years presenting to primary, secondary or tertiary care; it also aims to estimate the health economic and quality of life impact of RSV-attributable infection in this cohort. Such data will contribute to informing public health strategies to prevent RSV-associated infection, including use of preventative medications.

METHODS AND ANALYSIS

Parents/carers of children <3 years of age with RTI symptoms will consent for a respiratory sample (nasal swab) to be taken. Laboratory PCR testing will assess for the presence of RSV and/or other pathogens. Data will be obtained from medical records on demographics, comorbidities, severity of infection and hospitalisation outcomes. Parents will complete questionnaires on the impact of ongoing infection symptoms at day 14 and 28 following enrolment. The primary outcome is incidence of laboratory-confirmed RSV in children <3 years presenting to primary, secondary or tertiary care with RTI symptoms leading to health-seeking behaviours. Recruitment will be carried out from December 2021 to March 2023, encompassing two UK winter seasons and intervening months.

ETHICS AND DISSEMINATION

Ethical approval has been granted (21/WS/0142), and study findings will be published as per International Committee of Medical Journal Editors' guidelines.

Lung function and cognitive ability in children: a UK birth cohort study

BACKGROUND

Decreased adult lung function is associated with subsequent impairment in cognition. A similar relationship in early life could be of great policy importance, since childhood cognitive ability determines key adult outcomes, including socioeconomic status and mortality. We aimed to expand the very limited data available on this relationship in children, and hypothesised that reduced lung function would be longitudinally associated with decreased cognitive ability.

METHODS

Lung function was measured at age 8 (forced expiratory volume in one second (FEV₁), forced vital capacity (FVC); % predicted), and cognitive ability was measured at ages 8 (Wechsler Intelligence Scale for Children, third edition) and 15 (Wechsler Abbreviated Scale of Intelligence), in the Avon Longitudinal Study of Parents and Children. Potential confounders were identified as preterm birth, birth weight, breastfeeding duration, prenatal maternal smoking, childhood environmental tobacco smoke exposure, socioeconomic status and prenatal/childhood air pollution exposure. Univariable and multivariable linear models (n range=2332-6672) were fitted to assess the cross-sectional and longitudinal associations of lung function with cognitive ability, and change in cognitive ability between ages 8 and 15.

RESULTS

In univariate analyses, both FEV₁ and FVC at age 8 were associated with cognitive ability at both ages, but after adjustment, only FVC was associated with full-scale IQ (FSIQ) at ages 8 (β=0.09 (95% CI 0.05 to 0.12; p<0.001)) and 15 (β=0.06 (0.03 to 0.10; p=0.001)). We did not find evidence of an association between either lung function parameter and interval change in standardised FSIQ.

DISCUSSION

Reduced FVC, but not FEV₁, is independently associated with decreased cognitive ability in children. This low-magnitude association attenuates between ages 8 and 15, while no association is evident with longitudinal change in cognitive ability. Our results support a link between FVC and cognition across the life course, possibly due to shared genetic or environmental risk, rather than causation.

Single-arm, open-labelled, safety and tolerability of intrabronchial and nebulised bacteriophage treatment in children with cystic fibrosis and Pseudomonas aeruginosa

INTRODUCTION

Cystic fibrosis (CF) is a multisystem condition that is complicated by recurrent pulmonary infections requiring aggressive antibiotic treatment. This predisposes the patient to complications such as sensorineural hearing loss, renal impairment, hypersensitivity and the development of antibiotic resistance. Pseudomonas aeruginosa is one of the more common organisms which cause recurrent infections and result in greater morbidity and mortality in people living with CF. Bacteriophages have been identified as a potential alternative or adjunct to antibiotics. We hypothesise that bacteriophage therapy is a safe and well-tolerated treatment in children with CF infected with P. aeruginosa infection in their airways.

METHODS

This single-arm, open-labelled, non-randomised trial will run for a maximum period of 36 months with up to 10 participants. Adolescents (≥12 years and <18 years of age) who continue to shed P.aeruginosa (within 3 months of enrolment) despite undergoing eradication therapy previously, will be considered for this trial. Non-genetically modified bacteriophages that have demonstrated obligate lytic activity against each of the study participants' P. aeruginosa strains will be selected and prepared according to a combination of established protocols (isolation, purification, sterility testing and packaging) to achieve close to good manufacturing practice recommendations. The selected bacteriophage will be administered endo-bronchially first under direct vision, followed by two times a day nebulisation for 7 days in addition to standard CF treatment (intravenous antibiotics, physiotherapy to be completed as inpatient for 10-14 days). Safety and tolerability will be defined as the absence of (1) fever above 38.5°C occurring within 1 hour of the administration of the nebulised bacteriophage, (2) a 10% decline in spirometry (forced expiratory volume in 1 s %) measured preadministration and postadministration of the first dose of nebulised bacteriophage. Clinical reviews including repeat sputum cultures and spirometry will be performed at 3, 6, 9 and 12 months following bacteriophage treatment.

ETHICS AND DISSEMINATION

Our clinical trial is conducted in accordance with (1) good clinical practice, (2) Australian legislation, (3) National Health and Medical Research Council guidelines for the ethical conduct of research.

TRIAL REGISTRATION NUMBER

Australia and New Zealand Clinical Trial Registry (ACTRN12622000767707).

Pulmonary sequelae in 2-year-old children after hospitalisation for respiratory syncytial virus lower respiratory tract infection during infancy: an observational study

BACKGROUND

Respiratory syncytial virus (RSV) is the most common cause of hospitalisation for lower respiratory tract infection (LRTI) in children. RSV LRTI during early childhood may increase susceptibility to recurrent wheezing and asthma.

RESEARCH QUESTION

The aim of this study was to describe the pulmonary sequelae at 1 and 2 years of age following RSV LRTI hospitalisation during the first year of life in term infants.

STUDY DESIGN AND METHODS

A longitudinal case-control study was undertaken from April 2016 to December 2019. Cases constituted children hospitalised with PCR-confirmed RSV LRTI during infancy and controls were children not previously hospitalised with LRTI. A questionnaire detailing environmental and medical history, as well as a modified International Study of Asthma and Allergies (ISAAC) questionnaire, was administered, and pulmonary function testing, including oscillometry, tidal breath flow-volume loops and multiple breath wash-out, was performed, at one and two years of age.

RESULTS

One (n=308) and two-year-old (n=214) cases were more likely than one (n=292) and two-year-old (n=209) controls to have experienced clinical pulmonary symptoms, including wheezing ((55% vs 24%; p<0.001) and (61% vs 16%; p<0.001)), received treatment for wheezing ((17 vs 8%; p<0.001) and (51 vs 6%; p<0.001)) and had any admissions for wheezing ((31 vs 6%; p<0.001) and (46 vs 1.4%; p<0.001)) or any LRTI ((24 vs 2%; p<0.001) and (32 vs 1.4%; p<0.001)), after the initial RSV hospitalisation. RSV LRTI during infancy was associated with an increase in airway resistance by two years (22.46 vs 20.76 hPa.s.l^-1 (p=0.022)), along with a decrease in compliance at both one (-4.61 vs -3.09 hPa.s/l (p<0.001)) and two years (-0.99 vs 0.33 hPa.s/l¹ (p<0.001)). There was an increased work of breathing at one year, but this was no longer present at two years.

INTERPRETATION

RSV LRTI during infancy in cases was associated with more clinical and pulmonary function sequelae through to two years of age.

Evaluation of clinically relevant changes in the lung clearance index in children with cystic fibrosis and healthy controls

BACKGROUND

The limits of reproducibility of the lung clearance index (LCI) are higher in children with cystic fibrosis (CF) compared with healthy children, and it is currently unclear what defines a clinically meaningful change.

METHODS

In a prospective multisite observational study of children with CF and healthy controls (HCs), we measured LCI, FEV₁% predicted and symptom scores at quarterly visits over 2 years. Two reviewers performed a detailed review of visits to evaluate the frequency that between visit LCI changes outside ±10%, ±15%, ±20% represented a clinically relevant signal. In the setting of acute respiratory symptoms, we used a generalised estimating equation model, with a logit link function to determine the ability of LCI worsening at different thresholds to predict failure of lung function recovery at follow-up.

RESULTS

Clinically relevant LCI changes outside ±10%, ±15% and ±20% were observed at 25.7%, 15.0% and 8.3% of CF visits (n=744), respectively. The proportions of LCI changes categorised as noise, reflecting biological variability, were comparable between CF and HC at the 10% (CF 9.9% vs HC 13.0%), 15% (CF 4.3% vs HC 3.1%) and 20% (CF 2.4% vs HC 1.0%) thresholds. Compared with symptomatic CF visits without a worsening in LCI, events with ≥10% LCI increase were more likely to fail to recover baseline LCI at follow-up.

CONCLUSION

The limits of reproducibility of the LCI in healthy children can be used to detect clinically relevant changes and thus inform clinical care in children with CF.

Admixture mapping of severe asthma exacerbations in Hispanic/Latino children and youth

BACKGROUND

In the USA, genetically admixed populations have the highest asthma prevalence and severe asthma exacerbations rates. This could be explained not only by environmental factors but also by genetic variants that exert ethnic-specific effects. However, no admixture mapping has been performed for severe asthma exacerbations.

OBJECTIVE

We sought to identify genetic variants associated with severe asthma exacerbations in Hispanic/Latino subgroups by means of admixture mapping analyses and fine mapping, and to assess their transferability to other populations and potential functional roles.

METHODS

We performed an admixture mapping in 1124 Puerto Rican and 625 Mexican American children with asthma. Fine-mapping of the significant peaks was performed via allelic testing of common and rare variants. We performed replication across Hispanic/Latino subgroups, and the transferability to non-Hispanic/Latino populations was assessed in 1001 African Americans, 1250 Singaporeans and 941 Europeans with asthma. The effects of the variants on gene expression and DNA methylation from whole blood were also evaluated in participants with asthma and in silico with data obtained through public databases.

RESULTS

Genomewide significant associations of Indigenous American ancestry with severe asthma exacerbations were found at 5q32 in Mexican Americans as well as at 13q13-q13.2 and 3p13 in Puerto Ricans. The single nucleotide polymorphism (SNP) rs1144986 (C5orf46) showed consistent effects for severe asthma exacerbations across Hispanic/Latino subgroups, but it was not validated in non-Hispanics/Latinos. This SNP was associated with DPYSL3 DNA methylation and SCGB3A2 gene expression levels.

CONCLUSIONS

Admixture mapping study of asthma exacerbations revealed a novel locus that exhibited Hispanic/Latino-specific effects and regulated DPYSL3 and SCGB3A2.

Reduced lung function and health-related quality of life after treatment for pulmonary tuberculosis in Gambian children: a cross-sectional comparative study

BACKGROUND

Post-tuberculosis (post-TB) lung disease is an under-recognised consequence of pulmonary tuberculosis (pTB). We aimed to estimate the prevalence of residual lung function impairment and reduced health-related quality of life (HRQoL) in children after pTB treatment completion.

METHODS

We conducted a cross-sectional comparative study of children aged less than 15 years at TB diagnosis who had completed treatment for pTB at least 6 months previously with a comparator group of age-matched children without a history of pTB. Symptoms, spirometry and HRQoL measured with PedsQL scale were collected. Variables associated with lung function impairment were identified through logistic regression models.

RESULTS

We enrolled 68 post-TB cases (median age 8.9 (IQR 7.2-11.2) years) and 91 children in the comparison group (11.5 (8.0-13.7) years). Spirometry from 52 (76.5%) post-TB cases and 89 (94.5%) of the comparison group met the quality criteria for acceptability and repeatability. Lung function impairment was present in 20/52 (38.5%) post-TB cases and 15/86 (17.4%) in the comparison group, p=0.009. Previous pTB and a history of chronic cough were significantly associated with the presence of lung function impairment (p=0.047 and 0.006 respectively). Forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC) and FEV₁/FVC z-scores were significantly lower in the post-TB cases compared with the comparison group (p= <0.001, 0.014 and <0.001, respectively). The distribution of the self-reported physical health score, and parent-reported physical, emotional, psychological, social and total HRQoL scores were significantly lower in the post-TB cases compared with the comparison group.

CONCLUSIONS

Previous TB in children is associated with significantly impaired lung function and HRQoL.

Exercise as airway clearance therapy (ExACT) in cystic fibrosis: a UK-based e-Delphi survey of patients, caregivers and health professionals

Replacing traditional airway clearance therapy (tACT) with exercise (ExACT) in people with cystic fibrosis (pwCF) is a top research priority. A UK-based e-Delphi consensus was performed to inform the type(s), duration and intensity of ExACT. The expert panel comprised CF physiotherapists, doctors, pwCF and parents/partners. Exercise ACT was considered to be aerobic activity, of at least 20 min duration and intense enough to elicit deep breathing. Consensus was reached that assessment breaths, coughs and huffs should accompany exercise to remove loose secretions, with support for trials to investigate ExACT versus tACT during times of stable disease but not pulmonary exacerbations.

Relationship between impaired BMP signalling and clinical risk factors at early-stage vascular injury in the preterm infant

INTRODUCTION

Chronic lung disease, that is, bronchopulmonary dysplasia (BPD) is the most common complication in preterm infants and develops as a consequence of the misguided formation of the gas-exchange area undergoing prenatal and postnatal injury. Subsequent vascular disease and its progression into pulmonary arterial hypertension critically determines long-term outcome in the BPD infant but lacks identification of early, disease-defining changes.

METHODS

We link impaired bone morphogenetic protein (BMP) signalling to the earliest onset of vascular pathology in the human preterm lung and delineate the specific effects of the most prevalent prenatal and postnatal clinical risk factors for lung injury mimicking clinically relevant conditions in a multilayered animal model using wild-type and transgenic neonatal mice.

RESULTS

We demonstrate (1) the significant reduction in BMP receptor 2 (BMPR2) expression at the onset of vascular pathology in the lung of preterm infants, later mirrored by reduced plasma BMP protein levels in infants with developing BPD, (2) the rapid impairment (and persistent change) of BMPR2 signalling on postnatal exposure to hyperoxia and mechanical ventilation, aggravated by prenatal cigarette smoke in a preclinical mouse model and (3) a link to defective alveolar septation and matrix remodelling through platelet derived growth factor-receptor alpha deficiency. In a treatment approach, we partially reversed vascular pathology by BMPR2-targeted treatment with FK506 in vitro and in vivo.

CONCLUSION

We identified impaired BMP signalling as a hallmark of early vascular disease in the injured neonatal lung while outlining its promising potential as a future biomarker or therapeutic target in this growing, high-risk patient population.

Wheeze in the time of COVID-19: overcoming obstacles to an unusual diagnosis

This case is an example of a rare cause of a common clinical presentation (persistent lobar collapse with wheeze). We describe patient management from primary care through to a national thoracic referral centre. We highlight the importance of objective testing to support an asthma diagnosis and the need to consider alternative or additional diagnoses if a patient does not respond to treatment or the clinical course is unexpected. We highlight the importance of follow-up X-ray to determine whether atelectasis has resolved, which was significantly delayed in this case due to COVID-19 restrictions. Though rare, an endobronchial tumour should be considered if atelectasis persists and when planning endoscopy for a presumed foreign body, especially if the clinical history and patient factors make a foreign body less likely. Greater awareness of this as a differential may expedite diagnoses for patients in future. We show how virtual, multicentre, multidisciplinary meetings can aid rapid diagnosis, surgical planning and coordination of follow-up across centres.

Bronchopulmonary dysplasia and expiratory airflow at 8 years in children born extremely preterm in the post-surfactant era

BACKGROUND

It is unclear if bronchopulmonary dysplasia (BPD) is independently associated with reduced expiratory airflow at school age.

OBJECTIVE

To determine the independent associations of moderate-severe BPD, mild BPD, gestational age and birth weight z-score with expiratory airflow in children born extremely preterm (EP; <28 weeks' gestation).

METHODS

All EP survivors born in Victoria, Australia, in three eras (1991-1992, n=225; 1997, n=151; and 2005, n=170) were recruited at birth and 418/546 (77%) had valid spirometry data at 8 years. BPD was classified as moderate-severe (oxygen requirement at 36 weeks' postmenstrual age), or mild (oxygen >28 days but not at 36 weeks' postmenstrual age). Expiratory airflow variables, including the forced expired volume in 1 s (FEV₁), were measured and values converted to z-scores.

RESULTS

Compared with no BPD (n=94), moderate-severe BPD (n=193) was associated with a substantial reduction in expiratory airflow (eg, zFEV₁ mean difference -0.69, 95% CI -0.97 to -0.41; p<0.001), but mild BPD (n=131) was not (zFEV₁ mean difference 0.01, 95% CI -0.28 to 0.31; p=0.93). On multivariable analysis, moderate-severe BPD remained strongly associated with reduced airflow (zFEV₁ mean difference -0.63, 95% CI -0.92 to -0.33; p<0.001), but mild BPD (zFEV₁ mean difference 0.04, 95% CI -0.26 to 0.34; p=0.27), gestational age (zFEV₁ 0.06 mean increase per week, 95% CI -0.05 to 0.17; p=0.29) and birth weight z-score (zFEV₁ 0.07 mean increase per SD, 95% CI -0.06 to 0.20; p=0.28) were not.

CONCLUSIONS

In children born EP, moderate-severe BPD, but not mild BPD was independently associated with reduced expiratory airflow at 8 years.

Air quality, Environment and Respiratory Outcomes in Bronchopulmonary Dysplasia, the AERO-BPD cohort study: design and adaptation during the SARS-CoV-2 pandemic

INTRODUCTION

Almost half of all school-age children with bronchopulmonary dysplasia (BPD) have asthma-like symptoms and more suffer from lung function deficits. While air pollution and indoor respiratory irritants are known to affect high-risk populations of children, few studies have objectively evaluated environmental contributions to long-term respiratory morbidity in this population. This study aimed to examine the role of indoor environmental exposures on respiratory morbidity in children with BPD.

METHODS AND ANALYSIS

The Air quality, Environment and Respiratory Ouctomes in BPD (AERO-BPD) study is a prospective, single-centre observational study that will enrol a unique cohort of 240 children with BPD and carefully characterise participants and their indoor home environmental exposures. Measures of indoor air quality constituents will assess the relationship of nitrogen dioxide (NO2), particulate matter (PM2.5), nitric oxide (NO), temperature and humidity, as well as dust concentrations of allergens, with concurrently measured respiratory symptoms and lung function.Adaptations to the research protocol due to the SARS-CoV-2 pandemic included remote home environment and participant assessments.

ETHICS AND DISSEMINATION

Study protocol was approved by the Boston Children's Hospital Committee on Clinical Investigation. Dissemination will be in the form of peer-reviewed publications and participant information products.

TRIAL REGISTRATION NUMBER

NCT04107701.

Airway obstruction in young adults born extremely preterm or extremely low birth weight in the postsurfactant era

BACKGROUND

It is unknown if adults born <28 weeks or <1000 g since surfactant has been available are reaching their full airway growth potential.

OBJECTIVE

To compare expiratory airflow at 25 years and from 8 to 25 years of participants born <28 weeks or <1000 g with controls, and within the preterm group to compare those who had bronchopulmonary dysplasia with those who did not.

METHODS

All survivors born <28 weeks or <1000 g in 1991-1992 in Victoria, Australia, were eligible. Controls were born contemporaneously, weighing >2499 g. At 8, 18 and 25 years, expiratory airflows were measured and the results converted to z-scores. Outcomes were compared between groups at age 25 years, and trajectories (change in z-scores per year) from childhood were contrasted between groups.

RESULTS

Expiratory airflows were measured at 25 years on 164 of 297 (55%) preterm survivors and 130 of 260 (50%) controls. Preterm participants had substantially reduced airflow compared with controls at age 25 years (eg, zFEV₁; mean difference -0.97, 95% CI -1.23 to -0.71; p<0.001). Preterm participants had lower airflow trajectories than controls between 8 and 18 years, but not between 18 and 25 years. Within the preterm group, those who had bronchopulmonary dysplasia had worse airflows and trajectories than those who did not.

CONCLUSIONS

Young adults born <28 weeks or <1000 g in the surfactant era, particularly those who had bronchopulmonary dysplasia, have substantially reduced airway function compared with controls. Some are destined to develop COPD in later adult life.

Long-term outcomes of patients with pulmonary arteriovenous malformations considered for lung transplantation, compared with similarly hypoxaemic cohorts

INTRODUCTION

Pulmonary arteriovenous malformations (PAVMs) may not be amenable to treatment by embolisation or surgical resection, and many patients are left with significant hypoxaemia. Lung transplantation has been undertaken. There is no guidance on selection criteria.

METHODS

To guide transplantation listing assessments, the outcomes of the six patients who had been considered for transplantation were compared with a similarly hypoxaemic patient group recruited prospectively between 2005 and 2016 at the same UK institution.

RESULTS

Six patients had been formally considered for lung transplantation purely for PAVMs. One underwent a single lung transplantation for diffuse PAVMs and died within 4 weeks of surgery. The other five were not transplanted, in four cases at the patients' request. Their current survival ranges from 16 to 27 (median 21) years post-transplant assessment. Of 444 consecutive patients with PAVMs recruited between 2005 and 2016, 42 were similarly hypoxaemic to the 'transplant-considered' cohort (SaO2 <86.5%). Hypoxaemic cohorts maintained arterial oxygen content (CaO2) through secondary erythrocytosis and higher haemoglobin. The 'transplant-considered' cohort had similar CaO2 to the hypoxaemic comparator group, but higher Medical Research Council (MRC) dyspnoea scores (p=0.023), higher rates of cerebral abscesses (p=0.0043) and higher rates of venous thromboemboli (p=0.0009) that were evident before and after the decision to list for transplantation.

CONCLUSIONS

The non-transplanted patients demonstrated marked longevity. Symptoms and comorbidities were better predictors of health than oxygen measurements. While a case-by-case decision, weighing survival estimates and quality of life will help patients in their decision making, the data suggest a very strong case must be made before lung transplantation is considered.

Respiratory viruses in healthy infants and infants with cystic fibrosis: a prospective cohort study

RATIONALE

Acute viral respiratory tract infections in children with cystic fibrosis (CF) are known causes of disease exacerbation. The role of viral infections during infancy is, however, less known, although early infancy is thought to be a crucial period for CF disease development.We prospectively assessed symptomatic and asymptomatic viral detection in the first year of life in infants with CF and healthy controls.

METHODS

In a prospective cohort study, we included 31 infants with CF from the Swiss Cystic Fibrosis Infant Lung Development Cohort and 32 unselected, healthy infants from the Basel Bern Infant Lung Development Cohort and followed them throughout the first year of life. Respiratory symptoms were assessed by weekly telephone interviews. Biweekly nasal swabs were analysed for 10 different viruses and two atypical bacteria with real-time seven duplex PCR (CF=561, controls=712).

MEASUREMENTS AND RESULTS

Infants with CF and healthy controls showed similar numbers of swabs positive for virus (mean 42% vs 44%; OR 0.91, 95% CI 0.66 to 1.26, p=0.6). Virus-positive swabs were less often accompanied by respiratory symptoms in infants with CF (17% vs 23%; OR 0.64, 95% CI 0.43 to 0.95, p=0.026). This finding was pronounced for symptomatic human rhinovirus detection (7% vs 11%; OR 0.52, 95% CI 0.31 to 0.9, p=0.02).

CONCLUSIONS

Viral detection is not more frequent in infants with CF and respiratory symptoms during viral detection occur even less often than in healthy controls. It is likely an interplay of different factors such as local epithelial properties and immunological mechanisms that contribute to our findings.

Differential lower airway dendritic cell patterns may reveal distinct endotypes of RSV bronchiolitis

RATIONALE

The pathogenesis of respiratory syncytial virus (RSV) bronchiolitis in infants remains poorly understood. Mouse models implicate pulmonary T cells in the development of RSV disease. T cell responses are initiated by dendritic cells (DCs), which accumulate in lungs of RSV-infected mice. In infants with RSV bronchiolitis, previous reports have shown that DCs are mobilised to the nasal mucosa, but data on lower airway DC responses are lacking.

OBJECTIVE

To determine the presence and phenotype of DCs and associated immune cells in bronchoalveolar lavage (BAL) and peripheral blood samples from infants with RSV bronchiolitis.

METHODS

Infants intubated and ventilated due to severe RSV bronchiolitis or for planned surgery (controls with healthy lungs) underwent non-bronchoscopic BAL. Immune cells in BAL and blood samples were characterised by flow cytometry and cytokines measured by Human V-Plex Pro-inflammatory Panel 1 MSD kit.

MEASUREMENTS AND MAIN RESULTS

In RSV cases, BAL conventional DCs (cDCs), NK T cells, NK cells and pro-inflammatory cytokines accumulated, plasmacytoid DCs (pDCs) and T cells were present, and blood cDCs increased activation marker expression. When stratifying RSV cases by risk group, preterm and older (≥4 months) infants had fewer BAL pDCs than term born and younger (<4 months) infants, respectively.

CONCLUSIONS

cDCs accumulate in the lower airways during RSV bronchiolitis, are activated systemically and may, through activation of T cells, NK T cells and NK cells, contribute to RSV-induced inflammation and disease. In addition, the small population of airway pDCs in preterm and older infants may reveal a distinct endotype of RSV bronchiolitis with weak antiviral pDC responses.

Determinants of early-life lung function in African infants

BACKGROUND

Low lung function in early life is associated with later respiratory illness. There is limited data on lung function in African infants despite a high prevalence of respiratory disease.

AIM

To assess the determinants of early lung function in African infants.

METHOD

Infants enrolled in a South African birth cohort, the Drakenstein child health study, had lung function measured at 6-10 weeks of age. Measurements, made with the infant breathing via a facemask during natural sleep, included tidal breathing, sulfur hexafluoride multiple breath washout and the forced oscillation technique. Information on antenatal and early postnatal exposures was collected using questionnaires and urine cotinine. Household benzene exposure was measured antenatally.

RESULTS

Successful tests were obtained in 645/675 (95%) infants, median (IQR) age of 51 (46-58) days. Infant size, age and male gender were associated with larger tidal volume. Infants whose mothers smoked had lower tidal volumes (-1.6 mL (95% CI -3.0 to -0.1), p=0.04) and higher lung clearance index (0.1 turnovers (95% CI 0.01 to 0.3), p=0.03) compared with infants unexposed to tobacco smoke. Infants exposed to alcohol in utero or household benzene had lower time to peak tidal expiratory flow over total expiratory time ratios, 10% (95% CI -15.4% to -3.7%), p=0.002) and 3.0% (95% CI -5.2% to -0.7%, p=0.01) lower respectively compared with unexposed infants. HIV-exposed infants had higher tidal volumes (1.7 mL (95% CI 0.06 to 3.3) p=0.04) compared with infants whose mothers were HIV negative.

CONCLUSION

We identified several factors including infant size, sex, maternal smoking, maternal alcohol, maternal HIV and household benzene associated with altered early lung function, many of which are factors amenable to public health interventions. Long-term study of lung function and respiratory disease in these children is a priority to develop strategies to strengthen child health.

Do guidelines for treating chest disease in children use Cochrane Reviews effectively? A systematic review

Cochrane Reviews summarise best evidence and should inform guidelines. We assessed the use of Cochrane Reviews in the UK guidelines for paediatric respiratory disease. We found 21 guidelines which made 1025 recommendations, of which 96 could be informed by a Cochrane Review. In 38/96 recommendations (40%), some or all of the relevant Cochrane Reviews were not cited. We linked recommendations to 140 Cochrane Reviews. In 37/140 (26%) cases, the guideline recommendation did not fully agree with the Cochrane Review. Guideline developers may fail to use Cochrane Reviews or may make recommendations which are not in line with best evidence.

The lower airway microbiota in early cystic fibrosis lung disease: a longitudinal analysis

RATIONALE

In infants and young children with cystic fibrosis, lower airway infection and inflammation are associated with adverse respiratory outcomes. However, the role of lower airway microbiota in the pathogenesis of early cystic fibrosis lung disease remains uncertain.

OBJECTIVES

To assess the development of the lower airway microbiota over time in infants and young children with cystic fibrosis, and to explore its association with airway inflammation and pulmonary function at age 6 years.

METHODS

Serial, semi-annual bronchoscopies and bronchoalveolar lavage (BAL) procedures were performed in infants newly diagnosed with cystic fibrosis following newborn screening. Quantitative microbiological cultures and inflammatory marker (interleukin 8 and neutrophil elastase) measurements were undertaken contemporaneously. 16S ribosomal RNA gene sequencing was conducted on stored BAL samples. Spirometry results recorded at 6 years of age were extracted from medical records.

MEASUREMENTS AND MAIN RESULTS

Ninety-five BAL samples provided 16S ribosomal RNA gene data. These were collected from 48 subjects aged 1.2-78.3 months, including longitudinal samples from 27 subjects and 13 before age 6 months. The lower airway microbiota varied, but diversity decreased with advancing age. Detection of recognised cystic fibrosis bacterial pathogens was associated with reduced microbial diversity and greater lower airway inflammation. There was no association between the lower airway microbiota and pulmonary function at age 6 years.

CONCLUSIONS

In infants with cystic fibrosis, the lower airway microbiota is dynamic. Dominance of the microbiota by recognised cystic fibrosis bacterial pathogens is associated with increased lower airway inflammation, however early microbial diversity is not associated with pulmonary function at 6 years of age.

Altered lung structure and function in mid-childhood survivors of very preterm birth

RATIONALE

Survivors of preterm birth are at risk of chronic and lifelong pulmonary disease. Follow-up data describing lung structure and function are scarce in children born preterm during the surfactant era.

OBJECTIVES

To obtain comprehensive data on lung structure and function in mid-childhood from survivors of preterm birth. We aimed to explore relationships between lung structure, lung function and respiratory morbidity as well as early life contributors to poorer childhood respiratory outcomes.

METHODS

Lung function was tested at 9-11 years in children born at term (controls) and at ≤32 weeks gestation. Tests included spirometry, oscillatory mechanics, multiple breath nitrogen washout and diffusing capacity of the lung for carbon monoxide. Preterm children had CT of the chest and completed a respiratory symptoms questionnaire.

MAIN RESULTS

58 controls and 163 preterm children (99 with bronchopulmonary dysplasia) participated. Preterm children exhibited pulmonary obstruction and hyperinflation as well as abnormal peripheral lung mechanics compared with term controls. FEV₁ was improved by 0.10 z-scores for every additional week of gestation (95% CI 0.028 to 0.182; p=0.008) and by 0.34 z-scores per z-score increase in birth weight (0.124 to 0.548; p=0.002). Structural lung changes were present in 92% of preterm children, with total CT score decreased by 0.64 (-0.99 to -0.29; p<0.001) for each additional week of gestation. Obstruction was associated with increased subpleural opacities, bronchial wall thickening and hypoattenuated lung areas on inspiratory chest CT scans (p<0.05).

CONCLUSIONS

Abnormal lung structure in mid-childhood resulting from preterm birth in the contemporary era has important functional consequences.

Increasing airway obstruction from 8 to 18 years in extremely preterm/low-birthweight survivors born in the surfactant era

BACKGROUND

The evolution of airway obstruction into late adolescence of extremely preterm (gestational age <28 weeks) or extremely low-birthweight (birth weight <1000 g) survivors in the era after surfactant was introduced is unclear.

OBJECTIVE

To compare changes in spirometry from 8 to 18 years of age of a geographical cohort of preterm survivors with normal birth weight controls, and to determine higher risk groups within the preterm cohort.

METHODS

Of 297 extremely preterm/low-birthweight survivors born in 1991-1992 in the state of Victoria, Australia, 81% and 70% had spirometry at 8 and 18 years of age, respectively. Corresponding rates among 260 normal birth weight controls were 80% and 58%, respectively. Data were analysed using linear mixed models.

RESULTS

The preterm group had substantial impairments in airflow at both ages compared with controls (eg, mean differences in z-score for FEV₁; 8 years -1.02, 95% CI -1.21 to -0.82; 18 years -0.92, 95% CI -1.14 to -0.71). The preterm group had a greater increase in small airway obstruction between 8 and 18 years compared with controls. Within the preterm group, those who had bronchopulmonary dysplasia in the newborn period and those who were smokers at 18 years had airway obstruction that increased over time compared with those who did not.

CONCLUSIONS

Preterm survivors born in the surfactant era had significant impairments in airflow through childhood into late adolescence that increased over time compared with controls. At-risk preterm participants include those who had bronchopulmonary dysplasia, and smokers at 18 years.

Chest electrical impedance tomography examination, data analysis, terminology, clinical use and recommendations: consensus statement of the TRanslational EIT developmeNt stuDy group

Electrical impedance tomography (EIT) has undergone 30 years of development. Functional chest examinations with this technology are considered clinically relevant, especially for monitoring regional lung ventilation in mechanically ventilated patients and for regional pulmonary function testing in patients with chronic lung diseases. As EIT becomes an established medical technology, it requires consensus examination, nomenclature, data analysis and interpretation schemes. Such consensus is needed to compare, understand and reproduce study findings from and among different research groups, to enable large clinical trials and, ultimately, routine clinical use. Recommendations of how EIT findings can be applied to generate diagnoses and impact clinical decision-making and therapy planning are required. This consensus paper was prepared by an international working group, collaborating on the clinical promotion of EIT called TRanslational EIT developmeNt stuDy group. It addresses the stated needs by providing (1) a new classification of core processes involved in chest EIT examinations and data analysis, (2) focus on clinical applications with structured reviews and outlooks (separately for adult and neonatal/paediatric patients), (3) a structured framework to categorise and understand the relationships among analysis approaches and their clinical roles, (4) consensus, unified terminology with clinical user-friendly definitions and explanations, (5) a review of all major work in thoracic EIT and (6) recommendations for future development (193 pages of online supplements systematically linked with the chief sections of the main document). We expect this information to be useful for clinicians and researchers working with EIT, as well as for industry producers of this technology.

A clustering approach to identify severe bronchiolitis profiles in children

OBJECTIVE

Although bronchiolitis is generally considered a single disease, recent studies suggest heterogeneity. We aimed to identify severe bronchiolitis profiles using a clustering approach.

METHODS

We analysed data from two prospective, multicentre cohorts of children younger than 2 years hospitalised with bronchiolitis, one in the USA (2007-2010 winter seasons, n=2207) and one in Finland (2008-2010 winter seasons, n=408). Severe bronchiolitis profiles were determined by latent class analysis, classifying children based on clinical factors and viral aetiology.

RESULTS

In the US study, four profiles were identified. Profile A (12%) was characterised by history of wheezing and eczema, wheezing at the emergency department (ED) presentation and rhinovirus infection. Profile B (36%) included children with wheezing at the ED presentation, but, in contrast to profile A, most did not have history of wheezing or eczema; this profile had the largest probability of respiratory syncytial virus infection. Profile C (34%) was the most severely ill group, with longer hospital stay and moderate-to-severe retractions. Profile D (17%) had the least severe illness, including non-wheezing children with shorter length of stay. Two of these profiles (A and D) were replicated in the Finnish cohort; a third group ('BC') included Finnish children with characteristics of profiles B and/or C in the US population.

CONCLUSIONS

Several distinct clinical profiles (phenotypes) were identified by a clustering approach in two multicentre studies of children hospitalised for bronchiolitis. The observed heterogeneity has important implications for future research on the aetiology, management and long-term outcomes of bronchiolitis, such as future risk of childhood asthma.

The impact of BCG vaccination on tuberculin skin test responses in children is age dependent: evidence to be considered when screening children for tuberculosis infection

Background

Following exposure to TB, contacts are screened to target preventive treatment at those at high risk of developing TB. The UK has recently revised its recommendations for screening and now advises a 5 mm tuberculin skin test (TST) cut-off irrespective of age or BCG status. We sought to evaluate the impact of BCG on TST responses in UK children exposed to TB and the performance of different TST cut-offs to predict interferon γ release assay (IGRA) positivity.

Methods

Children <15 years old were recruited from 11 sites in the UK between January 2011 and December 2014 if exposed in their home to a source case with sputum smear or culture positive TB. Demographic details were collected and TST and IGRA undertaken. The impact of BCG vaccination on TST positivity was evaluated in IGRA-negative children, as was the performance of different TST cut-offs to predict IGRA positivity.

Results

Of 422 children recruited (median age 69 months; IQR: 32–113 months), 300 (71%) had been vaccinated with BCG. BCG vaccination affected the TST response in IGRA-negative children less than 5 years old but not in older children. A 5 mm TST cut-off demonstrated good sensitivity and specificity in BCG-unvaccinated children, and an excellent negative predictive value but was associated with low specificity (62.7%; 95% CI 56.1% to 69.0%) in BCG-vaccinated children. For BCG-vaccinated children, a 10 mm cut-off provided a high negative predictive value (97.7%; 95% CI 94.2% to 99.4%) with the positive predictive value increasing with increasing age of the child.

Discussion

BCG vaccination had little impact on TST size in children over 5 years of age. The revised TST cut-off recommended in the recent revision to the UK TB guidelines demonstrates good sensitivity but is associated with impaired specificity in BCG-vaccinated children.

Altered breathing mechanics and ventilatory response during exercise in children born extremely preterm

Background

Extreme preterm birth confers risk of long-term impairments in lung function and exercise capacity. There are limited data on the factors contributing to exercise limitation following extreme preterm birth. This study examined respiratory mechanics and ventilatory response during exercise in a large cohort of children born extremely preterm (EP).

Methods

This cohort study included children 8–12 years of age who were born EP (≤28 weeks gestation) between 1997 and 2004 and treated in a large regionalised neonatal intensive care unit in western Canada. EP children were divided into no/mild bronchopulmonary dysplasia (BPD) (ie, supplementary oxygen or ventilation ceased before 36 weeks gestational age; n=53) and moderate/severe BPD (ie, continued supplementary oxygen or ventilation at 36 weeks gestational age; n=50). Age-matched control children (n=65) were born at full term. All children attempted lung function and cardiopulmonary exercise testing measurements.

Results

Compared with control children, EP children had lower airway flows and diffusion capacity but preserved total lung capacity. Children with moderate/severe BPD had evidence of gas trapping relative to other groups. The mean difference in exercise capacity (as measured by oxygen uptake (VO₂)% predicted) in children with moderate/severe BPD was −18±5% and −14±5.0% below children with no/mild BPD and control children, respectively. Children with moderate/severe BPD demonstrated a potentiated ventilatory response and greater prevalence of expiratory flow limitation during exercise compared with other groups. Resting lung function did not correlate with exercise capacity.

Conclusions

Expiratory flow limitation and an exaggerated ventilatory response contribute to respiratory limitation to exercise in children born EP with moderate/severe BPD.

Lung function in woodsmoke-exposed Guatemalan children following a chimney stove intervention

RATIONALE

Household air pollution (HAP) from solid fuel combustion is a major contributor to the global burden of disease, with considerable impact from respiratory infections in children. The impact of HAP on lung function is unknown.

OBJECTIVES

The Childhood Exposure to Respirable Particulate Matter (CRECER) prospective cohort study followed Guatemalan children who participated in the Randomised Exposure Study of Pollution Indoors and Respiratory Effects (RESPIRE) trial of a chimney stove intervention to determine the effect of early childhood HAP exposure on growth of lung function.

METHODS

RESPIRE households with pregnant women or infant children were randomised to receive a chimney stove at the beginning or at the end of the 18-month trial. During CRECER, a subset of these children, as well as children from households with newly installed stoves, were followed with spirometry beginning at age 5. Biomass smoke exposure was measured using personal carbon monoxide tubes. Two-stage regression models were employed to analyse associations with lung function growth.

MEASUREMENTS AND MAIN RESULTS

Longitudinal peak expiratory flow (PEF) and FEV1 data were available for 443 and 437 children, respectively, aged 5-8 (mean follow-up 1.3 years). Decreases in PEF growth of 173 mL/min/year (95% CI -341 to -7) and FEV1 of 44 mL/year (95% CI -91 to 4) were observed with stove installation at 18 months compared with stove installation at birth in analyses adjusted for multiple covariates. No statistically significant associations were observed between personal HAP exposure and lung function.

CONCLUSIONS

A significant decrease in PEF growth and a large non-significant decrease in FEV1 growth were observed with later stove installation. Additional studies including longer follow-up and cleaner stoves or fuels are needed.

Transplacental sildenafil rescues lung abnormalities in the rabbit model of diaphragmatic hernia

INTRODUCTION

The management of congenital diaphragmatic hernia (DH) would benefit from an antenatal medical therapy, which addresses both lung hypoplasia and persistent pulmonary hypertension. We aimed at evaluating the pulmonary effects of sildenafil in the fetal rabbit model for DH.

METHODS

We performed a dose-finding study to achieve therapeutic fetal plasmatic concentrations without toxicity following maternal sildenafil administration. Subsequently, DH fetuses were randomly exposed to transplacental placebo or sildenafil 10 mg/kg/day from gestational day 24 until examination at term (day 30). Efficacy measures were ipsilateral pulmonary vascular and airway morphometry, micro-CT-based branching analysis, Doppler flow in the main pulmonary artery and postnatal lung mechanics.

RESULTS

Fetal sildenafil plasmatic concentration was above the minimal therapeutic level for at least 22 h/day without maternal and fetal side effects. The placebo-exposed DH fetuses had increased wall thickness in peripheral pulmonary vessels and significantly less fifth-order vessels compared with controls (CTR). Sildenafil-exposed DH fetuses, instead, had a medial and adventitial thickness in peripheral pulmonary vessels in the normal range and normal vascular branching. Fetal pulmonary artery Doppler showed a reduction of pulmonary vascular resistances both in DH and in CTR fetuses treated by sildenafil compared with the placebo-treated ones. Sildenafil also reversed the mean terminal bronchiolar density to normal and improved lung mechanics, yet without measurable impact on lung-to-bodyweight ratio.

CONCLUSIONS

In the rabbit model for DH, antenatal sildenafil rescues vascular branching and architecture, reduces pulmonary vascular resistances and also improves airway morphometry and respiratory mechanics.

Decreased lung function in 7-year-old children with early-life organophosphate exposure

BACKGROUND

Organophosphate pesticides are heavily used in agriculture, and adverse associations with respiratory health in occupational settings have been reported. However, most of the evidence comes from studies where there were no biomarkers of exposure and no objective outcome measurement. Non-occupational chronic effects among residents living in agricultural communities are less well described.

OBJECTIVE

To evaluate associations between early-life organophosphate exposure and lung function of children living in an agricultural community.

METHODS

Participants were 279 children from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) longitudinal birth cohort. The area under the curve for organophosphate exposure was determined by urinary diethyl and dimethyl dialkylphosphate metabolites of organophosphate pesticides, which were measured five times during childhood (6-60 months). Spirometry was performed at age 7 years. Regression models controlled for maternal smoking during pregnancy, season of birth, particulate matter concentrations with aerodynamic diameter ≤2.5 μm (PM2.5), breast feeding duration, mould and pets at home, distance of home from a highway, food insecurity, maternal education, season of spirometry, sex, height and technician.

RESULTS

Childhood diethyl, dimethyl and total dialkylphosphate concentrations were associated with significant decreases in lung function at age 7. Specifically, we found lower FEV1, (L/s) (ß=-0.16, 95% CI -0.30 to -0.02, p=0.03) and FVC (L) (ß=-0.17, 95% CI -0.34 to 0.01, p=0.06) per 10-fold increase of total dialkylphosphate levels.

CONCLUSIONS

Early-life organophosphate exposure as assessed by dialkylphosphate concentrations was adversely associated with 7-year-old children's lung function.

Chest radiographic abnormalities in HIV-infected African children: a longitudinal study

BACKGROUND

There is limited knowledge of chest radiographic abnormalities over time in HIV-infected children in resource-limited settings.

OBJECTIVE

To investigate the natural history of chest radiographic abnormalities in HIV-infected African children, and the impact of antiretroviral therapy (ART).

METHODS

Prospective longitudinal study of the association of chest radiographic findings with clinical and immunological parameters. Chest radiographs were performed at enrolment, 6-monthly, when initiating ART and if indicated clinically. Radiographic abnormalities were classified as normal, mild or moderate severity and considered persistent if present for 6 consecutive months or longer. An ordinal multiple logistic regression model assessed the association of enrolment and time-dependent variables with temporal radiographic findings.

RESULTS

258 children (median (IQR) age: 28 (13-51) months; median CD4+%: 21 (15-24)) were followed for a median of 24 (18-42) months. 70 (27%) were on ART at enrolment; 130 (50%) (median age: 33 (18-56) months) commenced ART during the study. 154 (60%) had persistent severe radiographic abnormalities, with median duration 18 (6-24) months. Among children on ART, 69% of radiographic changes across all 6-month transition periods were improvements, compared with 45% in those not on ART. Radiographic severity was associated with previous radiographic severity (OR=120.80; 95% CI 68.71 to 212.38), lack of ART (OR=1.72; 95% CI 1.29 to 2.27), enrolment age <18 months (OR=1.39; 95% CI 1.06 to 1.83), diffuse, severe radiographic abnormality at enrolment (OR=2.18; 95% CI 1.33 to 3.56), hospitalisation for lower respiratory tract infection during the previous 6 months (OR=1.88; 95% CI 1.06 to 3.30) and length of follow-up: at 18-24 months (OR=0.66; 95% CI 0.49 to 0.90), and at 30-54 months (OR=0.42; 95% CI 0.32 to 0.56).

CONCLUSIONS

Most children had severe radiographic abnormalities persisting for at least 18 months. ART was beneficial, reducing the risk of radiographic deterioration or increasing the likelihood of radiological improvement.

Lung sarcoidosis in children: update on disease expression and management

BACKGROUND

Sarcoidosis is a rare lung disease in children. The aim of the present study was to provide update information on disease presentation and progression, patient management and prognosis factors in a cohort of children with lung sarcoidosis.

METHODS

With the network of the French Reference Centre for Rare Lung Diseases (RespiRare), we collected information on a large cohort of paediatric thoracic sarcoidosis to provide information on disease presentation, management and outcome.

RESULTS

Forty-one patients were included with a median age at diagnosis of 11.8  years (1.1-15.8), mostly from Afro-Caribbean and Sub-Saharan origin. At diagnosis, 85% presented with a multi-organic disease, and no major differences were found regarding disease severity between the patients diagnosed before or after 10 years old. Corticosteroids were the most used treatment, with more intravenous pulses in the youngest patients. The 18-month outcome showed that patients diagnosed before 10 years old were more likely to recover (50% vs 29%), and presented fewer relapses (29% vs 58%). At 4-5 years of follow-up, relapses were mostly observed for patients diagnosed after 10 years old.

DISCUSSION

In the included children, mostly of Afro-Caribbean and Sub-Saharan origin, sarcoidosis seems severe, with multi-organic involvement and foreground general symptoms. Common prognosis factors are not suitable in paediatric patients, and a young age at diagnosis does not seem to be associated with a poorer prognosis. The study is ongoing to provide further information on the very-long-term follow-up of paediatric sarcoidosis.

Children and young adults with CF in the USA have better lung function compared with the UK

BACKGROUND

People with cystic fibrosis (CF) are managed differently in the USA and UK providing an opportunity to learn from differences in practice patterns.

OBJECTIVES

To compare cross-sectional demographics, practice patterns and clinical outcomes between US and UK CF patients.

METHODS

This was a cross-sectional study using 2010 data from patients in the US Cystic Fibrosis Foundation and the UK Cystic Fibrosis patient registries. The a priori outcome measures of interest were lung function and nutritional status. Descriptive statistics and two sample comparisons were performed. Stratification and multivariable linear regression were used to adjust for confounding.

RESULTS

The study cohort included 13 777 children and 11 058 adults from the USA and 3968 children and 3965 adults from the UK. In children, mean body mass index centiles were similar. Lung function (FEV1 and FVC% predicted) was significantly higher in US patients ages 6-25 years of age. In a regression model adjusted for only age, FEV1% predicted was on average 3.31% of predicted (95% CI 2.65 to 3.96) higher in the USA compared with the UK. When adjusted for age, age at diagnosis, gender, pancreatic insufficiency and genotype, FEV1% predicted was on average 3.03% of predicted (95% CI 2.37 to 3.69) higher in the USA compared with the UK These differences persisted despite adjustment for possible confounders. Hypertonic saline and dornase alfa were much more commonly prescribed in US children.

CONCLUSIONS

Children and young adults with CF have better lung function in the USA compared with the UK despite similar nutritional status.

SABRE: a multicentre randomised control trial of nebulised hypertonic saline in infants hospitalised with acute bronchiolitis

Aim

Acute bronchiolitis is the commonest cause for hospitalisation in infancy. Supportive care remains the cornerstone of current management and no other therapy has been shown to influence the course of the disease. It has been suggested that adding nebulised hypertonic saline to usual care may shorten the duration of hospitalisation. To determine whether hypertonic saline does have beneficial effects we undertook an open, multi-centre parallel-group, pragmatic RCT in ten UK hospitals.

Methods

Infants admitted to hospital with a clinical diagnosis of acute bronchiolitis and requiring oxygen therapy were randomised to receive usual care alone or nebulised 3% hypertonic saline (HS) administered 6-hourly. Randomisation was within 4 h of admission. The primary outcome was time to being assessed as ‘fit’ for discharge with secondary outcomes including time to discharge, incidence of adverse events together with follow up to 28 days assessing patient centred health related outcomes.

Results

A total of 317 infants were recruited to the study. 158 infants were randomised to HS (141 analysed) and 159 to standard care (149 analysed). There was no difference between the two arms in time to being declared fit for discharge (hazard ratio: 0−95, 95% CI: 0.75−1.20) nor to actual discharge (hazard ratio: 0.97, 95% CI: 0.76−1.23). There was no difference in adverse events. One infant in the HS group developed bradycardia with desaturation.

Conclusion

This study does not support the use of nebulised HS in the treatment of acute bronchiolitis over usual care with minimal handlings.

ClinicalTrials.gov registration number

NCT01469845.