Efficacy of azithromycin in severe asthma from the AMAZES randomised trial

Background

Low-dose azithromycin is an effective therapy for persistent asthma; however, its benefit in severe asthma is not defined.

Methods

Participants with severe asthma were identified from the AMAZES randomised, placebo-controlled trial of long-term (48 weeks) low-dose azithromycin. Participants who met one of the following severe asthma definitions were included: 1) Global Initiative for Asthma step 4 treatment with poor asthma control (asthma control questionnaire score ≥0.75); 2) International Severe Asthma Registry definition; 3) American Thoracic Society and European Respiratory Society severe asthma definitions. The rate of total exacerbations was calculated for each subgroup and efficacy of azithromycin compared with placebo. Asthma-related quality of life was assessed before and after treatment along with adverse effects.

Results

Azithromycin significantly reduced asthma exacerbations in each group. In patients meeting the American Thoracic Society and European Respiratory Society task force definition of severe asthma (n=211), the rate of exacerbations with treatment was 1.2 per person-year, which was significantly less than for placebo (2.01 per person-year), giving an incidence rate ratio (95% CI) of 0.63 (0.41, 0.96). The proportion of participants experiencing at least one asthma exacerbation was reduced by azithromycin from 64% to 49% (p=0.021). A similar beneficial treatment effect was seen in participants poorly controlled with Global Initiative for Asthma step 4 treatment and those with International Severe Asthma Registry-defined severe asthma. Azithromycin also significantly improved the quality of life in severe asthma (p<0.05). Treatment was well tolerated, with gastrointestinal symptoms being the main adverse effect.

Conclusion

Long-term, low-dose azithromycin reduced asthma exacerbations and improved the quality of life in patients with severe asthma, regardless of how this was defined. These data support the addition of azithromycin as a treatment option for patients with severe asthma.

Low-dose azithromycin is effective therapy for persistent asthma. AMAZES supports AZM as a treatment option for patients with severe asthma. Long-term, low-dose AZM reduces asthma exacerbations and improves quality of life in patients with severe asthma.http://bit.ly/2LWyjYz

Validation of the Eighth Edition TNM Lung Cancer Staging System

INTRODUCTION

We performed a validation study at our institution, the International Union Against Cancer (Union for International Cancer Control latest version of TNM Classification of Malignant Tumors Eighth Edition).

METHODS

Data were collected from the Queensland Oncology Online registry of NSCLC or SCLC cases between 2000 and 2015 and validated against the Queensland Integrated Lung Cancer Outcomes Project registry using case identification number, first name, last name, and date of birth. Where data were available, cases were classified according to the Union for International Cancer Control TNM seventh edition stage groupings and then compared with the eighth edition groupings. Kaplan-Meier curves were plotted, and the log-rank test of survival differences was performed with SPSS version 25 (IBM Corp, Armonk, NY).

RESULTS

Of the 3636 cases, 3352 and 1031 had complete clinical and pathologic staging, respectively. Median survival time was found to reduce with increasing clinical stage: seventh edition (IA: 88, IB: 44, IIA: 31, IIB: 18, IIIA: 15, IIIB: 8, and IV: 5 mo) versus eighth edition TNM stage (IA1: not reached, IA2: 88, IA3: 53, IB: 56, IIA: 36, IIB: 22, IIIA: 14, IIIB: 9, IIIC: 8, IVA: 6, and IVB: 3 mo). A similar overall pattern was reflected in the pathologic stage: seventh edition (IA: 124, IB: 110, IIA: 48, IIB: 42, IIIA: 26, IIIB: 31, and IV: 27 mo) versus eighth edition (IA1: not reached, IA2: 122, IA3: 125, IB: 144, IIA: 98, IIB: 57, IIIA: 31, IIIB: 24, and IVA: 7 mo). The log-rank test for survival curves was significant at p < 0.001.

CONCLUSIONS

Our external validation study confirms the prognostic accuracy of the eighth edition TNM lung cancer classification. Our analyses also indicated that IIIB, IIIC, and IVA stage groups had similar survival outcomes and suggest further research for refinement.

Clinical utility of exhaled nitric oxide fraction in the management of asthma and COPD

Exhaled nitric oxide fraction (F_ENO) values can be easily measured using portable analysers and are a surrogate marker of airway eosinophilia. F_ENO may be useful in diagnosing and monitoring conditions characterised by airway eosinophilia, i.e. asthma and possibly COPD. Many factors other than asthma and COPD affect F_ENO, especially atopy, which is associated with elevated F_ENO. One guideline recommends that F_ENO should be used as part of the diagnostic pathway for asthma diagnosis in adults and children aged >5 years. The role of F_ENO in monitoring asthma is even less clear, and most guidelines do not recommend its use outside of specialist asthma clinics. Currently, F_ENO is not recommended for diagnosis or monitoring of COPD. Although F_ENO is starting to find a place in the management of asthma in children and adults, considerably more research is required before the potential of F_ENO as an objective measurement in asthma and COPD can be realised.

Exhaled nitric oxide fraction (F_ENO) may be a useful test for diagnosing asthma in adults and in children but is currently not recommended for monitoring all patients with asthma or COPD 
http://bit.ly/2lmjXpm

Pre-hospital and emergency department pathways of care for exacerbations of chronic obstructive pulmonary disease (COPD)

Exacerbations are serious complications of chronic obstructive pulmonary disease (COPD) that often require acute care from pre-hospital and emergency department (ED) services. Despite being a frequent cause of emergency presentations, gaps remain in both literature and practice for emergency care pathways of COPD exacerbations. This review seeks to address these gaps and focuses on the literature of pre-hospital and ED systems of care and how these intersect with patients experiencing an exacerbation of COPD. The literature in this area is expanding rapidly; however, more research is required to further understand exacerbations and how they are addressed by emergency medical services worldwide. For the purpose of this review, the pre-hospital domain includes ambulance and other emergency transport services, and encompasses medical interventions delivered prior to arrival at an ED or hospital. The ED domain is defined as the area of a hospital or free-standing centre where patients arrive to receive emergent medical care prior to admission. In many studies there is a significant overlap between these two domains and frequent intersection and collaboration between services. In both of these domains, for the management of COPD exacerbations, several overarching themes have been identified in the literature. These include: the appropriate delivery of oxygen in the emergency setting; strategies to improve the provision of care in accordance with diagnostic and treatment guidelines; strategies to reduce the requirement for emergency presentations; and, technological advances including machine learning which are helping to improve emergency healthcare systems.

Airway pharmacology: treatment options and algorithms to treat patients with chronic obstructive pulmonary disease

Pharmacological treatment of patients with chronic obstructive pulmonary disease (COPD) aims to reduce disease burden and prevent future risk, especially exacerbations, hospitalizations, decline of lung function and quality of life, and mortality. This review will describe the basic pharmacology of the different classes of agents, followed by the effects they exert in patients with COPD, and the side effects. Targets for pharmacological treatments include airway smooth muscle contraction, inflammation, mucus production, alpha-1-antitrypsin deficiency and respiratory infection. Inhaled bronchodilators are the mainstay, with methylxanthines as secondary choice agents. Anti-inflammatory therapy can be administered as corticosteroids, phosphodiesterase inhibitor, and long-term macrolides such as azithromycin. Mucus production is addressed by use of mucolytics. In some countries, alpha-1-antitrypsin augmentation therapy is available for severe alpha-1-antitrypsin deficiency. The treatment of bacterial infection and/or colonization can be attempted with antibiotics; there is a dire need for effective anti-viral agents for the common viruses causing exacerbations of COPD. Since clinicians need to choose medications for their individual patients, algorithms for how to choose and change medication are increasingly being presented with more elements of treatable traits and personalized medicine.

COPD and the gut-lung axis: the therapeutic potential of fibre

Current management strategies for chronic obstructive pulmonary disease (COPD) incorporate a step-wise, multidisciplinary approach to effectively manage patient symptoms and prevent disease progression. However, there has been limited advancement in therapies to address the underlying cause of COPD pathogenesis. Recent research has established the link between the lungs and the gut-the gut-lung axis -and the gut microbiome is a major component. The gut microbiome is likely perturbed in COPD, contributing to chronic inflammation. Diet is a readily modifiable factor and the diet of COPD patients is often deficient in nutrients such as fibre. The metabolism of dietary fibre by gut microbiomes produces anti-inflammatory short chain fatty acid (SCFAs), which could protect against inflammation in the lungs. By addressing the 'fibre gap' in the diet of COPD patients, this targeted dietary intervention may reduce inflammation, both systemically and in the airways, and value-add to the paradigm shift in respiratory medicine, from reactive to personalised and participatory medicine.

Cognitive behavioural therapy (CBT) for patients with chronic lung disease and psychological comorbidities undergoing pulmonary rehabilitation

Background

The study aimed to determine the effects of adding cognitive behavioural therapy (CBT) to pulmonary rehabilitation to treat patients with chronic lung disease and comorbid anxiety and/or depression symptoms.

Methods

An open, parallel group, randomised controlled trial (RCT) was conducted, with longitudinal follow-up of 12 months. CBT was delivered in 2 face-to-face sessions and 4 phone sessions to patients with depression or anxiety undergoing pulmonary rehabilitation. The main outcome measures were change in Geriatric Depression Scale (GDS) and Geriatric Anxiety Inventory (GAI); secondary outcomes were St. Georges Respiratory Questionnaire (SGRQ), 6-minute walk test (6MWT) and pulmonary rehabilitation attendance.

Results

A total of 65 patients were randomized to Intervention (n=24) and Control (n=41) groups. Of the 24 patients in the Intervention group, 6 patients (25%) withdrew and 4 patients (12.5%) failed to attend more than 2 CBT sessions, which was significantly more than the Control group. The majority of patients (75.4%) had chronic obstructive pulmonary disease. Fourteen (21.5%) had symptoms of depression only, 12 (18.4%) had symptoms of anxiety only, and 39 (60.0%) had symptoms of both anxiety and depression. In the Intervention group, GDS significantly improved at the end of pulmonary rehabilitation (mean difference -3.1, 95% CI: -4.39 to -1.70; P=0.0001), 3 months follow-up (mean difference -1.5, 95% CI: -4.17 to -0.75; P=0.008), and at 12 months follow-up (mean difference -1.6, 95% CI: -3.29 to -0.03, P=0.04), compared to baseline. The Control group demonstrated improvement in GDS by the end of pulmonary rehabilitation (mean difference -1.3, 95% CI: -2.4 to -0.27; P=0.01) which was not maintained at 3 months (P=0.14) and 12 months (P=0.25). GAI significantly improved by the end of rehabilitation in both the Intervention (mean difference -2.6, 95% -4.69 to -0.57; P=0.01) and Control groups (mean difference -2.6, 95% -4.16 to -1.14; P=0.001) and there was no significant improvement at 3 and 12 months. No statistically significant differences in changes in GDS or GAI were observed between the Intervention and Control groups at any time point. There was no significant improvement in SGRQ or 6MWT. There was a significant increase in attended pulmonary rehabilitation sessions in the Intervention group, compared to the Control group (mean difference 1.59; 95% CI: 0.11 to 3.07; P=0.03).

Conclusions

In this RCT of patients with chronic lung diseases attending pulmonary rehabilitation, there was no evidence found for improved symptoms of anxiety or depression or health-related quality of life with the addition of CBT given in a mixed face-to-face and telephone format, compared to usual care. Slower than anticipated recruitment, leading to a smaller than planned sample size, and a high dropout rate in the group allocated to CBT may have limited the effectiveness of the behavioural intervention approach in this study.

Extracellular vesicles in chronic obstructive pulmonary disease (COPD)

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease characterised by chronic inflammation and significant airflow obstruction that is not fully reversible, and is one of the leading causes of morbidity and mortality worldwide. Extracellular vesicles (EVs) (including apoptotic bodies, microvesicles and exosomes) are small membrane-bound vesicles released by nearly all cell types and can be found in various bodily fluids including blood, sputum and urine. EVs are key mediators in cell-cell communication due to their ability to exchange information to recipient cells, influencing physiological and pathological conditions using their bioactive cargo (DNA, RNA, miRNA, proteins and other metabolites). Therefore the main aim of this review is to highlight recent evidence of the potential use of EVs as diagnostic and therapeutic biomarkers for COPD managements, as well as EVs potential role in COPD pathogenesis. As EVs have been under intense investigation as diagnostic and therapeutic biomarkers for lung disease, in relation to COPD, key studies have identified EVs as potential biomarkers to distinguish exacerbations from stable state, and to characterise COPD phenotypes. EVs are also linked to key inflammatory mediators in COPD progression. In addition, bacteria and their EV cargo influence the lung microenvironment. Further recent therapeutic approaches and advances have seen EVs bioengineered as novel drug delivery vehicles, which could potentially have clinical utility for lung diseases such as COPD.

Potential clinical utility of multiple target quantitative polymerase chain reaction (qPCR) array to detect microbial pathogens in patients with chronic obstructive pulmonary disease (COPD)

Background

Culture-independent methods such as quantitative polymerase chain reaction (qPCR) are more sensitive for detecting pathogens than conventional culture. This study aimed to test the clinical potential of a multiple target qPCR array in identifying sputum pathogens, compared to traditional culture.

Methods

Forty chronic obstructive pulmonary disease (COPD) patients provided spontaneous sputum and blood samples during an exacerbation event (n=25 patients) and in stable state (n=15 patients). Sputum was processed and analysed by microscopy, culture and sensitivity testing (MCS) to identify living microbial isolates, and multiple target qPCR (44 targets for bacterial and fungal pathogens and antibiotic resistance genes), and 16S rRNA gene sequencing.

Results

Six microbial isolates (5 bacterial, 1 fungal) were cultured from 20 exacerbation and 10 stable patient sputum samples. Four of these microbial isolates had their presence in patient sputum confirmed by qPCR. All bacterial targets detected by qPCR were further confirmed by 16S rRNA gene sequencing at a genus level. qPCR identified significantly more bacterial pathogens than culture (P<0.001). The most prevalent bacterial species identified by qPCR were Streptococcus pneumoniae (72% of patients), Pseudomonas aeruginosa (40%), Prevotella oris (32%) and Haemophilus influenzae (17%). Microbial species diversity and richness were not significantly different between samples obtained from exacerbating and clinically stable cases. 16S rRNA gene sequencing identified Pseudomonas 4408227 (P=0.022, FDR =0.043 AUC =0.72) as a significantly different bacterial OTU (operational taxonomic units) in exacerbation sputum samples compared to stable state samples.

Conclusions

Multiple target qPCR was more sensitive for detection of sputum pathogens in COPD patients than conventional culture. 16S rRNA gene sequencing confirmed the identity at a genus level of all bacterial targets detected by qPCR, as well as identifying bacterial OTUs that could potentially be used to distinguish between exacerbation and stable COPD disease states. Multiple target qPCR pathogen detection in the sputum of COPD patients warrants further investigation to determine how it may influence COPD clinical management.

Diagnostic approach to chronic dyspnoea in adults

Chronic dyspnoea, or breathlessness for more than four weeks duration, is a common symptom in adults presenting to primary and tertiary care. It often presents a diagnostic challenge due to the wide spectrum of underlying disease, which is multifactorial in approximately one third of cases. Challenges in diagnosis include an often non-diagnostic clinical assessment, difficulty in selecting the most appropriate investigations and correct speciality referral for further diagnostic assessment. In patients presenting with chronic dyspnoea, history and physical examination are often non-specific with key findings more useful as negative predictive factors. There is a broad range of simple to specialised investigations that may be utilised in the diagnostic workup. Several diagnostic algorithms incorporating different tiers of investigations have been tested in studies of chronic dyspnoea patients but there is currently very limited data that test a diagnostic algorithm against standard clinical care. In this review we propose a diagnostic pathway with primary, secondary and tertiary level investigations for patients with chronic dyspnoea. This pathway is based on the combination of previously tested diagnostic algorithms in the literature, to assist clinicians in their diagnostic workup of chronic dyspnoea patients. Further research is needed to further evaluate diagnostic algorithms in this setting and to test this diagnostic pathway in clinical practice.

Nutritional support in chronic obstructive pulmonary disease (COPD): an evidence update

Chronic obstructive pulmonary disease (COPD) primarily affects the lungs but due to the accompanying chronic systematic inflammation and the symptoms associated with the disease there are many extrapulmonary effects which include complex physical and metabolic adaptations. These changes have been associated with reduced exercise capacity, increased nutritional requirements, altered metabolic processes and compromised nutritional intake. As a result, nutritional depletion in COPD is multi-faceted and can involve imbalances of energy (weight loss), protein (sarcopenia), and periods of markedly increased inflammation (pulmonary cachexia) which can increase nutritional losses. As a result, depletion of both fat-mass (FM) and fat-free mass (FFM) can occur. There is good evidence that nutritional support, in the form of oral nutritional supplements (ONS), can overcome energy and protein imbalances resulting in improved nutritional status and functional capacity. However, in order to treat the aetiology of sarcopenia, frailty and cachexia, it is likely that targeted multi-modal interventions are required to address energy and protein imbalance, specific nutrient deficiencies, reduced androgens and targeted exercise training. Furthermore, interventions taking a disease-course approach, are likely to hold the key to effectively managing the common and costly problem of nutritional depletion in COPD.

Chronic obstructive pulmonary disease (COPD) and lung cancer: common pathways for pathogenesis

Chronic obstructive pulmonary disease (COPD) and lung cancer comprise the leading causes of lung disease-related mortality worldwide. Exposure to tobacco smoke is a mutual aetiology underlying the two diseases, accounting for almost 90% of cases. There is accumulating evidence supporting the role of immune dysfunction, the lung microbiome, extracellular vesicles and underlying genetic susceptibility in the development of COPD and lung cancer. Further, epigenetic factors, involving DNA methylation and microRNA expression, have been implicated in both diseases. Chronic inflammation is a key feature of COPD and could be a potential driver of lung cancer development. Using next generation technologies, further studies investigating the genomics, epigenetics and gene-environment interaction in key molecular pathways will continue to elucidate the pathogenic mechanisms underlying the development of COPD and lung cancer, and contribute to the development of novel diagnostic and prognostic tools for early intervention and personalised therapeutic strategies.

The cytotoxic, inflammatory and oxidative potential of coconut oil-substituted diesel emissions on bronchial epithelial cells at an air-liquid interface

Diesel emissions contain high levels of particulate matter (PM) which can have a severe effect on the airways. Diesel PM can be effectively reduced with the substitution of diesel fuel with a biofuel such as vegetable oil. Unfortunately, very little is known about the cellular effects of these alternative diesel emissions on the airways. The aim of this study was to test whether coconut oil substitution in diesel fuel reduces the adverse effect of diesel emission exposure on human bronchial epithelial cells. Human bronchial epithelial cells were cultured at air-liquid interface for 7 days and exposed to diesel engine emissions from conventional diesel fuel or diesel fuel blended with raw coconut oil at low (10%), moderate (15%) and high (20%) proportions. Cell viability, inflammation, antioxidant production and xenobiotic metabolism were measured. Compared to conventional diesel, low fractional coconut oil substitution (10% and 15%) reduced inflammation and increased antioxidant expression, whereas higher fractional coconut oil (20%) reduced cell viability and increased inflammation. Therefore, cellular responses after exposure to alternative diesel emission are dependent on fuel composition.

Cost of screening for lung cancer in Australia

BACKGROUND

Lung cancer screening can reduce lung cancer mortality. Australian cost estimates are important to inform policy but remain uncertain.

AIM

To describe the first direct medical costs associated with lung cancer screening in Australia.

METHODS

Single-centre prospective screening cohort. Healthy volunteers (age 60-74 years, current or former smokers quit <15 years prior to enrolment, ≥30 pack-years exposure) underwent baseline and two annual incidence computed tomography (CT) screening scans. Health status and healthcare usage data were collated for 5 years. The main outcome measures were: rates of lung cancer; individual healthcare resource use derived from multiple data sources adjusted to 2018 Australian Medicare Benefits Schedule values.

RESULTS

A total of 256, 239, 233 participants was screened at each round respectively; 12 participants were diagnosed with lung cancer during screening and 2 during follow-up: 9 underwent surgery, 4 received concurrent chemoradiation, 1 received palliative chemotherapy. One surgical case died from lymphoma 1407 days after diagnosis, all other surgical cases survived >5 years. Non-surgical median survival post-diagnosis was 654 days. Gross trial cost was Australian dollar (AU$) 965 665 (AU$397 396 CT scans; AU$29 303 false-positive scan work-up; AU$96 340 true-positive scan workup; AU$336 914 lung cancer treatment; AU$104 712 lung cancer follow-up post-treatment). Average total direct medical cost per participant was AU$3 768. Average direct cost of surgery was AU$22 659; average non-surgical cost was AU$47 395 (radiotherapy, chemotherapy, palliative care).

CONCLUSIONS

Advanced cancer cost more to treat and had worse survival than early cancer. Screening costs are similar to international studies and suggest that lung cancer early detection could limit treatment costs and improve outcomes.

Evaluation of an innovative mobile health programme for the self-management of chronic obstructive pulmonary disease (MH-COPD): protocol of a randomised controlled trial

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death globally. In outpatient care, the self-management of COPD is essential, but patient adherence to this remains suboptimal. The objective of this study is to examine whether an innovative mobile health (mHealth)-enabled care programme (MH-COPD) will improve the patient self-management and relevant health outcomes.

METHODS AND ANALYSIS

A prospective open randomised controlled trial has been designed. In the trial, patients with COPD will be recruited from The Prince Charles Hospital, Brisbane, Australia. They will then be randomised to participate in either the MH-COPD intervention group (n=50 patients), or usual care control group (UC-COPD) (n=50 patients) for 6 months. The MH-COPD programme has been designed to integrate an mHealth system within a clinical COPD care service. In the programme, participants will use a mHealth application at home to review educational videos, monitor COPD symptoms, use an electronic action plan, modify the risk factors of cigarette smoking and regular physical activity, and learn to use inhalers optimally. All participants will be assessed at baseline, 3 months and 6 months. The primary outcomes will be COPD symptoms and quality of life. The secondary outcomes will be patient adherence, physical activity, smoking cessation, use of COPD medicines, frequency of COPD exacerbations and hospital readmissions, and user experience of the mobile app.

ETHICS AND DISSEMINATION

The clinical trial has been approved by The Prince Charles Hospital Human Research Ethics Committee (HREC/16/QPCH/252). The recruitment and follow-up of the trial will be from January 2019 to December 2020. The study outcomes will be disseminated according to the Consolidated Standards of Reporting Trials statement through a journal publication, approximately 6 months after finishing data collection.

TRIAL REGISTRATION NUMBER

ACTRN12618001091291.

Clinical management practices of life-threatening asthma: an audit of practices in intensive care

OBJECTIVE

Lack of management guidelines for lifethreatening asthma (LTA) risks practice variation. This study aims to elucidate management practices of LTA in the intensive care unit (ICU).

DESIGN

A retrospective cohort study.

SETTING

Thirteen participating ICUs in Australia between July 2010 and June 2013.

PARTICIPANTS

Patients with the principal diagnosis of LTA.

MAIN OUTCOME MEASURES

Clinical history, ICU management, patient outcomes, ward education and discharge plans.

RESULTS

Of the 270 (267 patients) ICU admissions, 69% were female, with a median age of 39 years (interquartile range [IQR], 26-53 years); 119 (44%) were current smokers; 89 patients (33%) previously required ICU admission, of whom 23 (25%) were intubated. The median ICU stay was 2 days (IQR, 2-4 days). Three patients (1%) died. Seventy-nine patients (29%) received non-invasive ventilation, with 11 (14%) needing subsequent invasive ventilation. Sixty-eight patients (25%) were intubated, with the majority of patients receiving volume cycled synchronised intermittent mechanical ventilation (n = 63; 93%). Drugs used included ß2-agonist by intravenous infusion (n = 69; 26%), inhaled adrenaline (n = 15; 6%) or an adrenaline intravenous infusion (n = 23; 9%), inhaled anticholinergics (n = 238; 90%), systemic corticosteroids (n = 232; 88%), antibiotics (n = 126; 48%) and antivirals (n = 22; 8%). When suitable, 105 patients (n = 200; 53%) had an asthma management plan and 122 (n = 202; 60%) had asthma education upon hospital discharge. Myopathy was associated with hyperglycaemia requiring treatment (odds ratio [OR], 31.6; 95% CI, 2.1-474). Asthma education was more common under specialist thoracic medicine care (OR, 3.0; 95% CI, 1.61-5.54).

CONCLUSION

In LTA, practice variation is common, with opportunities to improve discharge management plans and asthma education.

The effect of diesel emission exposure on primary human bronchial epithelial cells from a COPD cohort: N-acetylcysteine as a potential protective intervention

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) will be the third leading cause of death world-wide by 2020. Prolonged exposure to particulate matter is associated with COPD progression and mortality. Diesel emissions are a major contributor to particulate matter pollution. In this study we test a therapeutic antioxidant, N-acetylcysteine (NAC), for its ability to protect bronchial epithelial cells (pHBECs) from patients with COPD from adverse effects of diesel emission exposure.

METHODS

pHBECs from patients with or without COPD were cultured at air-liquid interface (ALI). Cells were exposed to diesel emissions for 30 min with or without 3-h post-exposure treatment with 5 mM N-acetylcysteine (NAC). Filtered laboratory air was tested as a negative control. Cell responses (cell viability, inflammation and oxidative stress) and gene expression profiles for intracellular and immune signaling were assessed.

RESULTS

Diesel emissions exposure increased IL-8 secretion and production, antioxidant production, and cytochrome P450 1a1 (CYP1a1) mRNA expression and suppressed superoxide dismutase-1 (SOD1) mRNA expression in bronchial epithelial cells from COPD patients. Treatment with N-acetyl cysteine attenuated the suppression of SOD1. Nanostring gene expression profiling of the filtered air controls showed COPD epithelial cells have increased expression of MHC class II and an interferon signaling profile.

CONCLUSIONS

This study indicates that bronchial epithelial cells from COPD patients may be vulnerable to diesel emission exposure due to reduced antioxidant capacity, and elevated CYP1a1 mRNA expression. NAC did not appear to offer protection. Future research will be needed to explore other means of recovering oxidant capacity in COPD airways.

Primary human bronchial epithelial cell responses to diesel and biodiesel emissions at an air-liquid interface

INTRODUCTION

Diesel emissions have a high level of particulate matter which can cause inflammation and oxidative stress in the airways. A strategy to reduce diesel particulate matter and the associated adverse effects is the use of biodiesels and fuel additives. However, very little is known about the biological effects of these alternative emissions. The aim of this study is to compare the effect of biodiesel and triacetin/biodiesel emissions on primary human bronchial epithelial cells (pHBECs) compared to diesel emissions.

METHODS

pHBECs were exposed to diesel, biodiesel (20%, 50% and 100% biodiesel derived from coconut oil) and triacetin/biodiesel (4% and 10% triacetin) emissions for 30 min at air-liquid interface. Cell viability (cellular metabolism, cell death, CASP3 mRNA expression and BCL2 mRNA expression), inflammation (IL-8 and IL-6 secretion), antioxidant production (HO-1 mRNA expression) and xenobiotic metabolism (CYP1a1 mRNA expression) were measured.

RESULTS

Biodiesel emissions (B50) reduced cell viability, and increased oxidative stress. Triacetin/biodiesel emissions (B90) decreased cell viability and increased antioxidant production, inflammation and xenobiotic metabolism. Biodiesel emissions (B100) reduced cell viability, and increased IL-8 secretion and xenobiotic metabolism.

CONCLUSIONS

Biodiesel substitution in diesel fuel and triacetin substitution in biodiesel can increase the adverse effects of diesel emissions of pHBECs. Further studies of the effect of these diesel fuel alternatives on pHBECs are required.

Polydisperse Microparticle Transport and Deposition to the Terminal Bronchioles in a Heterogeneous Vasculature Tree

The atmospheric particles from different sources, and the therapeutic particles from various drug delivery devices, exhibit a complex size distribution, and the particles are mostly polydisperse. The limited available in vitro, and the wide range of in silico models have improved understanding of the relationship between monodisperse particle deposition and therapeutic aerosol transport. However, comprehensive polydisperse transport and deposition (TD) data for the terminal airways is still unavailable. Therefore, to benefit future drug therapeutics, the present numerical model illustrates detailed polydisperse particle TD in the terminal bronchioles for the first time. Euler-Lagrange approach and Rosin-Rammler diameter distribution is used for polydisperse particles. The numerical results show higher deposition efficiency (DE) in the right lung. Specifically, the larger the particle diameter (d_p > 5 μm), the higher the DE at the bifurcation area of the upper airways is, whereas for the smaller particle (d_p < 5 μm), the DE is higher at the bifurcation wall. The overall deposition pattern shows a different deposition hot spot for different diameter particle. These comprehensive lobe-specific polydisperse particle deposition studies will increase understanding of actual inhalation for particle TD, which could potentially increase the efficiency of pharmaceutical aerosol delivery at the targeted position of the terminal airways.

The contribution of respiratory microbiome analysis to a treatable traits model of care

The composition of the airway microbiome in patients with chronic airway diseases, such as severe asthma, chronic obstructive pulmonary disease (COPD), bronchiectasis and cystic fibrosis (CF), has the potential to inform a precision model of clinical care. Patients with these conditions share overlapping disease characteristics, including airway inflammation and airflow limitation. The clinical management of chronic respiratory conditions is increasingly moving away from a one-size-fits-all model based on primary diagnosis, towards care targeting individual disease traits, and is particularly useful for subgroups of patients who respond poorly to conventional therapies. Respiratory microbiome analysis is an important potential contributor to such a 'treatable traits' approach, providing insight into both microbial drivers of airways disease, and the selective characteristics of the changing lower airway environment. We explore the potential to integrate respiratory microbiome analysis into a treatable traits model of clinical care and provide a practical guide to the application and clinical interpretation of respiratory microbiome analysis.