Randomised, phase 1/2a trial of ION-827359, an antisense oligonucleotide inhibitor of ENaC.

Background: Hyperactivity of epithelial sodium channel (ENaC) with increased sodium absorption is a feature of cystic fibrosis (CF). ION-827359 is a 2.5-generation antisense oligonucleotide targeted to reduce ENaC protein. This study evaluated ION-827359 safety, pharmacokinetics and pharmacodynamics. Methods: In this three-part phase 1/2a, double-blind, randomised study, healthy volunteers received single doses of placebo or ION-827359 (3, 10, 37.5 or 100 mg; Part 1) or multiple doses of placebo or ION-827359 (5×10 mg, 5×37.5 mg, 5×75 mg or 10×37.5 mg; Part 2). People with CF (pwCF) received multiple doses of placebo or ION-827359 (5×10 mg, 5×37.5 mg, 5×75 mg and 5×100 mg; Part 3). Treatments were administered via Pari eFlow© mesh nebuliser. The primary outcome was safety; pharmacokinetic and pharmacodynamic parameters were also assessed. Results: 64 healthy volunteers and 34 pwCF were enrolled. ION-827359 was well tolerated with an acceptable safety profile. There were no clinically relevant changes in laboratory values, ECG or vital signs. Systemic drug exposure was low (plasma half-life ∼2 weeks). Multiple doses of ION-827359 were associated with dose-dependent reductions in ENaC mRNA in bronchial epithelium. After multiple dosing, forced expiratory volume in 1 s was slightly higher in pwCF receiving ION-827359 (+2.9% with ION-827359 100 mg versus placebo; p=0.27). Conclusions: The tolerability and safety of ION-827359 appear favourable at this stage of investigation. Reduction in ENaC mRNA supports mechanistic efficacy at the doses and regimens tested, and supports further investigation of ION-827359 in pwCF.

Monocyte migration profiles define disease severity in acute COVID-19 and unique features of long COVID.

BACKGROUND: COVID-19 is associated with a dysregulated immune response but it is unclear how immune dysfunction contributes to the chronic morbidity persisting in many COVID-19 patients during convalescence (long COVID). METHODS: We assessed phenotypical and functional changes of monocytes in COVID-19 patients during hospitalisation and up to 9 months of convalescence following COVID-19, respiratory syncytial virus or influenza A. Patients with progressive fibrosing interstitial lung disease were included as a positive control for severe, ongoing lung injury. RESULTS: Monocyte alterations in acute COVID-19 patients included aberrant expression of leukocyte migration molecules, continuing into convalescence (n=142) and corresponding with specific symptoms of long COVID. Long COVID patients with unresolved lung injury, indicated by sustained shortness of breath and abnormal chest radiology, were defined by high monocyte expression of C-X-C motif chemokine receptor 6 (CXCR6) (p<0.0001) and adhesion molecule P-selectin glycoprotein ligand 1 (p<0.01), alongside preferential migration of monocytes towards the CXCR6 ligand C-X-C motif chemokine ligand 16 (CXCL16) (p<0.05), which is abundantly expressed in the lung. Monocyte CXCR6 and lung CXCL16 were heightened in patients with progressive fibrosing interstitial lung disease (p<0.001), confirming a role for the CXCR6-CXCL16 axis in ongoing lung injury. Conversely, monocytes from long COVID patients with ongoing fatigue exhibited a sustained reduction of the prostaglandin-generating enzyme cyclooxygenase 2 (p<0.01) and CXCR2 expression (p<0.05). These monocyte changes were not present in respiratory syncytial virus or influenza A convalescence. CONCLUSIONS: Our data define unique monocyte signatures that define subgroups of long COVID patients, indicating a key role for monocyte migration in COVID-19 pathophysiology. Targeting these pathways may provide novel therapeutic opportunities in COVID-19 patients with persistent morbidity.

Device-assessed sleep and physical activity in individuals recovering from a hospital admission for COVID-19: a multicentre study.

BACKGROUND: The number of individuals recovering from severe COVID-19 is increasing rapidly. However, little is known about physical behaviours that make up the 24-h cycle within these individuals. This study aimed to describe physical behaviours following hospital admission for COVID-19 at eight months post-discharge including associations with acute illness severity and ongoing symptoms. METHODS: One thousand seventy-seven patients with COVID-19 discharged from hospital between March and November 2020 were recruited. Using a 14-day wear protocol, wrist-worn accelerometers were sent to participants after a five-month follow-up assessment. Acute illness severity was assessed by the WHO clinical progression scale, and the severity of ongoing symptoms was assessed using four previously reported data-driven clinical recovery clusters. Two existing control populations of office workers and individuals with type 2 diabetes were comparators. RESULTS: Valid accelerometer data from 253 women and 462 men were included. Women engaged in a mean ± SD of 14.9 ± 14.7 min/day of moderate-to-vigorous physical activity (MVPA), with 12.1 ± 1.7 h/day spent inactive and 7.2 ± 1.1 h/day asleep. The values for men were 21.0 ± 22.3 and 12.6 ± 1.7 h /day and 6.9 ± 1.1 h/day, respectively. Over 60% of women and men did not have any days containing a 30-min bout of MVPA. Variability in sleep timing was approximately 2 h in men and women. More severe acute illness was associated with lower total activity and MVPA in recovery. The very severe recovery cluster was associated with fewer days/week containing continuous bouts of MVPA, longer total sleep time, and higher variability in sleep timing. Patients post-hospitalisation with COVID-19 had lower levels of physical activity, greater sleep variability, and lower sleep efficiency than a similarly aged cohort of office workers or those with type 2 diabetes. CONCLUSIONS: Those recovering from a hospital admission for COVID-19 have low levels of physical activity and disrupted patterns of sleep several months after discharge. Our comparative cohorts indicate that the long-term impact of COVID-19 on physical behaviours is significant.

Longitudinal assessment of lung clearance index to monitor disease progression in children and adults with cystic fibrosis.

BACKGROUND: Lung clearance index (LCI) is a valuable research tool in cystic fibrosis (CF) but clinical application has been limited by technical challenges and uncertainty about how to interpret longitudinal change. In order to help inform clinical practice, this study aimed to assess feasibility, repeatability and longitudinal LCI change in children and adults with CF with predominantly mild baseline disease. METHODS: Prospective, 3-year, multicentre, observational study of repeated LCI measurement at time of clinical review in patients with CF >5 years, delivered using a rapid wash-in system. RESULTS: 112 patients completed at least one LCI assessment and 98 (90%) were still under follow-up at study end. The median (IQR) age was 14.7 (8.6-22.2) years and the mean (SD) FEV1 z-score was -1.2 (1.3). Of 81 subjects with normal FEV1 (>-2 z-scores), 63% had raised LCI (indicating worse lung function). For repeat stable measurements within 6 months, the mean (limits of agreement) change in LCI was 0.9% (-18.8% to 20.7%). A latent class growth model analysis identified four discrete clusters with high accuracy, differentiated by baseline LCI and FEV1. Baseline LCI was the strongest factor associated with longitudinal change. The median total test time was under 19 min. CONCLUSIONS: Most patients with CF with well-preserved lung function show stable LCI over time. Cluster behaviours can be identified and baseline LCI is a risk factor for future progression. These results support the use of LCI in clinical practice in identifying patients at risk of lung function decline.

ERS International Congress 2020: highlights from the Paediatric Assembly.

In this review, the Paediatric Assembly of the European Respiratory Society (ERS) presents a summary of the highlights and most relevant findings in the field of paediatric respiratory medicine presented at the virtual ERS International Congress 2020. Early Career Members of the ERS and Chairs of the different Groups comprising the Paediatric Assembly discuss a selection of the presented research. These cover a wide range of research areas, including respiratory physiology and sleep, asthma and allergy, cystic fibrosis, respiratory infection and immunology, neonatology and intensive care, epidemiology, bronchology and lung and airway development. Specifically, we describe the long-term effect in lung function of premature birth, mode of delivery and chronic respiratory conditions such as cystic fibrosis. In paediatric asthma, we present risk factors, phenotypes and their progression with age, and the challenges in diagnosis. We confirm the value of the lung clearance index to detect early lung changes in cystic fibrosis. For bronchiectasis treatment, we highlight the importance of identifying treatable traits. The use of biomarkers and genotypes to identify infants at risk of long-term respiratory morbidity is also discussed. We present the long-term impact on respiratory health of early life and fetal exposures to maternal obesity and intrauterine hypoxia, mechanical ventilation hyperoxia, aeroallergens, air pollution, vitamin A deficient intake and bronchitis. Moreover, we report on the use of metabolomics and genetic analysis to understand the effect of these exposures on lung growth and alveolar development. Finally, we stress the need to establish multidisciplinary teams to treat complex airway pathologies.

Impact of airway Exophiala spp. on children with cystic fibrosis.

INTRODUCTION: Isolation of Exophiala species from sputum samples has become increasingly reported in Cystic Fibrosis (CF). However, the clinical significance of Exophiala spp. with regards to the paediatric CF population is unknown. METHODS: A case control study was undertaken to compare CF children with and without chronic Exophiala spp. in their sputum samples. Demographic and clinical data were collected retrospectively for each case from the date of Exophiala isolation and for 12 months preceding isolation. Each case was compared to three age and year-matched controls. To determine the effect of Exophiala on clinical course, patients were then followed for 12 months post isolation. RESULTS: In total, 27 of 244 eligible paediatric CF patients (11%) isolated Exophiala spp. on more than one occasion. There were no significant differences in the key clinical parameters: spirometry, mean number of intravenous (IV) antibiotic days and body mass index (BMI), between cases and controls (p = 0.91, p = 0.56 and p = 0.63 respectively). A higher proportion of cases isolated Candida spp. (67% vs 21%, p < 0.0001) and Aspergillus fumigatus (37% vs 26%, p = 0.37). There was no clinically significant difference in spirometry, mean number of IV antibiotic days and BMI in cases pre and post Exophiala spp. isolation. Posaconazole was the only drug used that successfully eradicated Exophiala. CONCLUSION: Despite the frequent isolation of Exophiala spp. in this cohort, in most patients it is not associated with significant clinical deterioration. It does however seem to be associated with isolation of other fungi.

The effect of acute maximal exercise on the regional distribution of ventilation using ventilation MRI in CF.

BACKGROUND: The importance of exercise in the management of people with CF is well recognised, yet the effect of exercise on lung function is not well understood. FEV1 is insensitive to the detection of small changes in lung function. Ventilation MRI and LCI are both more sensitive to mild lung disease than FEV1 and may be better suited to assess the effects of exercise. Here we assessed the short-term effects of maximal exercise on the distribution of ventilation using ventilation MRI and LCI. METHODS: Patients with CF and a range of lung disease were assessed. Baseline LCI and ventilation MRI was followed by a maximal cardio-pulmonary exercise test (CPET). Repeated ventilation MRI was performed within 30 minutes of exercise termination, followed by LCI and finally by FEV1. RESULTS: 13 patients were recruited and completed all assessments. Mean (SD) age was 25 (10) years and mean (SD) FEV1 z-score was -1.8 (1.7). Mean LCI at baseline was 8.2, mean ventilation defect percentage on MRI (VDP) was 7.3%. All patients performed maximal CPET. Post-exercise, there was a visible change in lung ventilation in 85% of patients, including two patients with increased ventilation heterogeneity post-CPET who had normal FEV1. VDP and LCI were significantly reduced post-exercise (p < 0.05) and 45% of patients had a significant change in VDP. CONCLUSIONS: Acute maximal exercise directly affects the distribution of ventilation on ventilation MRI in patients with CF. This suggests that exercise is beneficial in CF and that ventilation MRI is suitable to assess airway clearance efficacy.

Antibiotic treatment for Burkholderia cepacia complex in people with cystic fibrosis experiencing a pulmonary exacerbation.

BACKGROUND: Chronic pulmonary infection is a hallmark of lung disease in cystic fibrosis. Infections dominated by organisms of the Burkholderia cepacia complex, a group of at least 18 closely-related species of gram-negative bacteria, are particularly difficult to treat. These infections may be associated with a fulminant necrotising pneumonia. Burkholderia cepacia complex bacteria are resistant to many common antibiotics and able to acquire resistance against many more. Following patient segregation in cystic fibrosis medical care, the more virulent epidemic strains are not as frequent, and new infections are more likely to be with less virulent environmentally-acquired strains. Although evidence-based guidelines exist for treating respiratory exacerbations involving Pseudomonas aeruginosa, these cannot be extended to Burkholderia cepacia complex infections. This review, which is an update of a previous review, aims to assess the available trial evidence for the choice and application of treatments for these infections. OBJECTIVES: To assess the effectiveness and safety of different antibiotic regimens in people with cystic fibrosis experiencing an exacerbation and chronically infected with organisms of the Burkholderia cepacia complex. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews. Date of latest search: 29 May 2019. SELECTION CRITERIA: Randomised and quasi-randomised controlled trials of treatments for exacerbations of pulmonary symptoms in people with cystic fibrosis chronically infected with organisms of the Burkholderia cepacia complex. DATA COLLECTION AND ANALYSIS: No relevant trials were identified. MAIN RESULTS: No trials were included in this review. AUTHORS' CONCLUSIONS: Burkholderia cepacia complex infections present a significant challenge for people with cystic fibrosis and their clinicians. The incidence is likely to increase as the cystic fibrosis population ages; and managing and treating these infections will become more important. There is a lack of trial evidence to guide decision making and no conclusions can be drawn from this review about the optimal antibiotic regimens for people with cystic fibrosis who have chronic Burkholderia cepacia complex infections. Clinicians must continue to assess each person individually, taking into account in vitro antibiotic susceptibility data, previous clinical responses and their own experience. Multicentre randomised clinical trials are needed to assess the effectiveness of different antibiotic regimens in people with cystic fibrosis infected with organisms of the Burkholderia cepacia complex.

Composition of airway bacterial community correlates with chest HRCT in adults with bronchiectasis.

BACKGROUND AND OBJECTIVE: In bronchiectasis (BE) not caused by cystic fibrosis, chronic, polymicrobial airway infection contributes to the underlying pathogenesis of disease. There is little information on whether bacterial community composition relates to clinical status. We determined the relationship between bacterial community composition, chest high-resolution computed tomography (HRCT) scores and clinical markers in BE. METHODS: A subgroup of BE patients from a previous cross-sectional study were analysed. Spontaneously expectorated sputum was analysed using culture-independent sequencing on the Roche 454-FLX platform covering the V1-V3 region of the 16S rRNA marker gene. Chest HRCT scans, multiple breath washout, spirometry and blood inflammatory markers were collected. Spearman's rank (r) correlation coefficient was used to assess relationships. RESULTS: Data from 21 patients were analysed (mean (SD) age: 64.0 (7.7); female : male 14:7; mean (SD) forced expiratory volume in 1 s (FEV1 ): 76.5 (17.2)). All bacterial community composition metrics (bacterial richness, diversity, evenness and dominance) correlated with percentage BE score, with more severe HRCT abnormality relating to lower bacterial richness, evenness and diversity (range r = -0.47 to -0.66; P < 0.05). Inflammation (C-reactive protein and white cell count) was greater in patients with lower diversity and richness (range r = -0.44 to -0.47; P < 0.05). Bacterial community characteristics did not correlate with lung function. CONCLUSION: This is the first study to indicate a relationship between bacterial community characteristics by 16S rRNA marker gene sequencing, structural damage as determined by chest HRCT and clinical measures in BE. The association between loss of diversity and chest HRCT severity suggests that bacterial dominance with pathogenic bacteria may contribute to disease pathology.

Simultaneous sulfur hexafluoride and nitrogen multiple-breath washout (MBW) to examine inherent differences in MBW outcomes.

Multiple-breath washout (MBW) can be performed with different gases (sulfur hexafluoride (SF6-) and nitrogen (N2)) and different devices, all of which give discrepant results. This study aimed to confirm previously reported differences and explore factors influencing discrepant results; equipment factors or the physical properties of gases used. METHODS: Healthy controls (HCs) and participants with cystic fibrosis (CF) completed MBW trials on two commercially available devices (Exhalyzer D (N2) and Innocor (SF6)). Simultaneous washout of both gases at the same time on the commercial equipment and simultaneous washouts using a respiratory mass spectrometer (RMS) were completed in subsets. Primary outcomes were lung clearance index (LCI), breath number and time required to washout. RESULTS: Breath number was higher with N2 washout than SF6 in both HCs and patients with CF, whether washouts were completed individually or simultaneously. The difference was greater in more advanced disease, largely caused by differences in the final part of the washout. Results from commercial devices were similar to those obtained with the RMS. CONCLUSIONS: N2 MBW results were higher than SF6 MBW, with some of the largest differences reported to date being observed. The biggest impact was at the end of the washout and this was even the case when gases were washed out simultaneously. N2 and SF6 MBW results are inherently different and should be considered as independent measurements.

A novel method for infant multiple breath washout: First report in clinical practice.

BACKGROUND: Lung clearance index (LCI), measured using multiple breath inert gas washout (MBW) is a potentially useful test in infants with respiratory disease, particularly cystic fibrosis (CF). Clinical use is limited however by the need for specialist staff and equipment. We have previously described a novel method for infant MBW suitable for use outside of specialist laboratories. This study describes its performance in vivo in infants with CF and healthy controls, including a limited comparison with the respiratory mass spectrometer. METHODS: Children aged less than 2 years with CF and controls underwent MBW testing on a single occasion. The practical applicability of the system was determined by the number of successful duplicate tests and within-subject repeatability. RESULTS: Twenty-five children (seven with CF, 18 healthy controls, all sedated with chloral hydrate) attempted MBW. Twenty patients (seven with CF) successfully underwent duplicate testing (80% success rate). Mean within-subject coefficient of variation for functional residual capacity (FRC) was 7.2% and for LCI 5.9%. Comparison of LCI with the mass spectrometer was limited but gave very similar values for LCI and FRC in those patients who underwent technically adequate tests with both methods. CONCLUSIONS: We have described a new MBW method that is feasible and reproducible in sedated infants. Results fall within the expected range, and well within accuracy limits set by international guidelines. This could provide a more accessible alternative to previously described systems for infant MBW, and overcomes many of the technical challenges inherent in conventional MBW.

Implications of fatherhood in cystic fibrosis.

Advances in fertility treatment mean that men with CF are increasingly able to become fathers. Here we report clinical outcomes in 22 men with CF who have become fathers for the first time. Overall mean (SD) FEV1% predicted declined from 60.1(18.0)% to 57.4(20.2)% from baseline to 1 year (p = 0.15). Weight declined from mean (SD) 70.6 kg (10.4) to 68.3 kg (10.2), p = 0.0001. Six men had an FEV1% predicted ≤40% at the time of birth: 50% died or received lung transplantation within the 12-15 month follow up period. Becoming a parent is a major life event, and as with new mothers, fathers with CF may be at risk of significant decline.

Assessing arthritis in the context of cystic fibrosis.

Inflammatory arthritis in the context of cystic fibrosis (CF) can represent a diagnostic and therapeutic challenge. Poor recognition and under-treatment of musculoskeletal conditions increases symptom burden, affects quality of life, and may lead to changes to an individual's ability to carry out activities of daily living and to exercise. A careful assessment and multidisciplinary approach is essential when considering a diagnosis of CF-associated arthritis (CFA), both in terms of identifying other treatable conditions, such as rheumatoid arthritis, and effectively addressing symptoms. In this collaboration between CF specialists and Rheumatologists, we consider joint symptoms in patients with CF, with a focus on CFA. We offer a differential diagnosis list and consider steps to assess and manage CF patients presenting with arthralgia including appropriate up-to-date rheumatological assessment.

Patterns of regional lung physiology in cystic fibrosis using ventilation magnetic resonance imaging and multiple-breath washout.

Hyperpolarised helium-3 (3He) ventilation magnetic resonance imaging (MRI) and multiple-breath washout (MBW) are sensitive methods for detecting lung disease in cystic fibrosis (CF). We aimed to explore their relationship across a broad range of CF disease severity and patient age, as well as assess the effect of inhaled lung volume on ventilation distribution.32 children and adults with CF underwent MBW and 3He-MRI at a lung volume of end-inspiratory tidal volume (EIV T). In addition, 28 patients performed 3He-MRI at total lung capacity. 3He-MRI scans were quantitatively analysed for ventilation defect percentage (VDP), ventilation heterogeneity index (VHI) and the number and size of individual contiguous ventilation defects. From MBW, the lung clearance index, convection-dependent ventilation heterogeneity (Scond) and convection-diffusion-dependent ventilation heterogeneity (Sacin) were calculated.VDP and VHI at EIV T strongly correlated with lung clearance index (r=0.89 and r=0.88, respectively), Sacin (r=0.84 and r=0.82, respectively) and forced expiratory volume in 1 s (FEV1) (r=-0.79 and r=-0.78, respectively). Two distinct 3He-MRI patterns were highlighted: patients with abnormal FEV1 had significantly (p<0.001) larger, but fewer, contiguous defects than those with normal FEV1, who tended to have numerous small volume defects. These two MRI patterns were delineated by a VDP of ∼10%. At total lung capacity, when compared to EIV T, VDP and VHI reduced in all subjects (p<0.001), demonstrating improved ventilation distribution and regions of volume-reversible and nonreversible ventilation abnormalities.

Preschool Multiple-Breath Washout Testing. An Official American Thoracic Society Technical Statement.

BACKGROUND: Obstructive airway disease is nonuniformly distributed throughout the bronchial tree, although the extent to which this occurs can vary among conditions. The multiple-breath washout (MBW) test offers important insights into pediatric lung disease, not available through spirometry or resistance measurements. The European Respiratory Society/American Thoracic Society inert gas washout consensus statement led to the emergence of validated commercial equipment for the age group 6 years and above; specific recommendations for preschool children were beyond the scope of the document. Subsequently, the focus has shifted to MBW applications within preschool subjects (aged 2-6 yr), where a "window of opportunity" exists for early diagnosis of obstructive lung disease and intervention. METHODS: This preschool-specific technical standards document was developed by an international group of experts, with expertise in both custom-built and commercial MBW equipment. A comprehensive review of published evidence was performed. RESULTS: Recommendations were devised across areas that place specific age-related demands on MBW systems. Citing evidence where available in the literature, recommendations are made regarding procedures that should be used to achieve robust MBW results in the preschool age range. The present work also highlights the important unanswered questions that need to be addressed in future work. CONCLUSIONS: Consensus recommendations are outlined to direct interested groups of manufacturers, researchers, and clinicians in preschool device design, test performance, and data analysis for the MBW technique.

Supine posture changes lung volumes and increases ventilation heterogeneity in cystic fibrosis.

INTRODUCTION: Lung Clearance Index (LCI) is recognised as an early marker of cystic fibrosis (CF) lung disease. The effect of posture on LCI however is important when considering longitudinal measurements from infancy and when comparing LCI to imaging studies. METHODS: 35 children with CF and 28 healthy controls (HC) were assessed. Multiple breath washout (MBW) was performed both sitting and supine in triplicate and analysed for LCI, Scond, Sacin, and lung volumes. These values were also corrected for the Fowler dead-space to create 'alveolar' indices. RESULTS: From sitting to supine there was a significant increase in LCI and a significant decrease in FRC for both CF and HC (p<0.01). LCI, when adjusted to estimate 'alveolar' LCI (LCIalv), increased the magnitude of change with posture for both LCIalv and FRCalv in both groups, with a greater effect of change in lung volume in HC compared with children with CF. The % change in LCIalv for all subjects correlated significantly with lung volume % changes, most notably tidal volume/functional residual capacity (Vtalv/FRCalv (r = 0.54,p<0.001)). CONCLUSION: There is a significant increase in LCI from sitting to supine, which we believe to be in part due to changes in lung volume and also increasing ventilation heterogeneity related to posture. This may have implications in longitudinal measurements from infancy to older childhood and for studies comparing supine imaging methods to LCI.