Sensitisation to recombinant Aspergillus fumigatus allergens and clinical outcomes in COPD.

BACKGROUND: Variable clinical outcomes are reported with fungal sensitisation in chronic obstructive pulmonary disease (COPD), and it remains unclear which fungi and what allergens associate with the poorest outcomes. The use of recombinant as opposed to crude allergens for such assessment is unknown. METHODS: A prospective multicentre assessment of stable COPD (n=614) was undertaken in five hospitals across three countries: Singapore, Malaysia and Hong Kong. Clinical and serological assessment was performed against a panel of 35 fungal allergens including crude and recombinant Aspergillus and non-Aspergillus allergens. Unsupervised clustering and topological data analysis (TDA) approaches were employed using the measured sensitisation responses to elucidate if sensitisation subgroups exist and their related clinical outcomes. RESULTS: Aspergillus fumigatus sensitisation was associated with increased exacerbations in COPD. Unsupervised cluster analyses revealed two "fungal sensitisation" groups. The first was characterised by Aspergillus sensitisation and increased exacerbations, poorer lung function and worse prognosis. Polysensitisation in this group conferred even poorer outcome. The second group, characterised by Cladosporium sensitisation, was more symptomatic. Significant numbers of individuals demonstrated sensitisation responses to only recombinant (as opposed to crude) A. fumigatus allergens f 1, 3, 5 and 6, and exhibited increased exacerbations, poorer lung function and an overall worse prognosis. TDA validated these findings and additionally identified a subgroup within Aspergillus-sensitised COPD of patients with frequent exacerbations. CONCLUSION: Aspergillus sensitisation is a treatable trait in COPD. Measuring sensitisation responses to recombinant Aspergillus allergens identifies an important patient subgroup with poor COPD outcomes that remains overlooked by assessment of only crude Aspergillus allergens.

Respiratory admissions before and during the COVID-19 pandemic with mediation analysis of air pollutants, mask-wearing and influenza rates.

BACKGROUND AND OBJECTIVE: Decline in hospitalizations for various respiratory diseases has been reported during the COVID-19 pandemic, but what led to such an observation is uncertain. METHODS: This was a territory-wide, retrospective cohort study involving all public hospital admissions in Hong Kong from 1 January 2017 to 31 December 2020. Hospital admissions for respiratory diseases, including asthma, COPD and non-COVID pneumonia, were assessed. COVID-related admissions were excluded from this study. The time of commencement of the pandemic was taken from the fourth week of January 2020. The associations between air pollutant levels, influenza and mask-wearing rates with hospital admissions were assessed by mediation analyses. RESULTS: There were altogether 19,485, 78,693 and 238,781 admissions for asthma, COPD and non-COVID pneumonia from January 2017 to December 2020. There was a marked reduction in hospital admissions of asthma, COPD and non-COVID pneumonia (37%, 36% and 12% decrease in average daily admissions, respectively) during the COVID-19 pandemic compared to before. Air pollutant levels and influenza rate were decreased while mask-wearing rate was increased. Collinearity of mask-wearing rates and pandemic year was observed. For COPD, NO2 , SO2 , PM10 and influenza rates (4%, 11%, 4% and 4% of the total effect, respectively), while for non-COVID pneumonia, PM10 and influenza rates (11% and 52%, respectively) had significant mediation effect on changes in hospital admissions before and during the COVID-19 pandemic. CONCLUSION: During the COVID-19 pandemic, a decrease in air pollutant levels and influenza rate had mediation effect on the reduction in hospitalizations of COPD and non-COVID pneumonia.

Comparison of the 12-month impact of COVID-19 and SARS on physiological capacity and health-related quality of life.

BACKGROUND: Little is known about the differences in medium to long-term recovery on spirometry, 6-minute walking distance (6MWD) and health-related quality of life (HRQoL) between COVID-19 and SARS. METHODS: We performed a 12-month prospective study on COVID-19 survivors. The changes in dynamic lung volumes at spirometry (%predicted FEV1, %predicted FVC), 6MWD and HRQoL at 1-3, 6 to 12 months were compared against a historical cohort of SARS survivors using the same study protocol. The residual radiological changes in HRCT in COVID-19 survivors were correlated with their functional capacity. RESULTS: 108 COVID-19 survivors of various disease severity (asymptomatic 2.9%, mild 33.3%, moderate 47.2%, severe 8.3%, critical 8.3%) were recruited. When compared with 97 SARS survivors, 108 COVID-19 survivors were older (48.1 ± 16.4 vs. 36.1 ± 9.5 years, p < 0.001) and required less additional support during hospitalization; with lower dynamic lung volumes, shorter 6MWD and better physical component score. Both groups of survivors had comparable changes in these parameters at subsequent follow-ups. Both COVID-19 and SARS survivors had similar mental component score (MCS) at 6 and 12 months. COVID-19 survivors initially experienced less (between-group difference, -3.1, 95% confidence interval [CI] -5.5 to -0.7, p = 0.012) and then more improvement (between-group difference 2.9, 95%, CI 0.8 to 5.1, p = 0.007) than SARS survivors in the MCS at 1-3 to 6 months and 6 to 12 months respectively. Forty (44.0%) out of 91 COVID-19 survivors had residual abnormalities on HRCT at 12 months, with a negative correlation between the severity scores of parenchymal changes and 6MWD (r=-0.239, p < 0.05). CONCLUSIONS: COVID-19 survivors demonstrated a similar recovery speed in dynamic lung volumes and exercise capacity, but different paces of psychological recovery as SARS survivors in the convalescent phase. The severity of parenchymal changes in HRCT is negatively correlated with the 6MWD of COVID-19 survivors. TRIAL REGISTRATION: This prospective study was registered at ClinicalTrials.gov on 2 November 2020 (Identifier: NCT04611243).

Effect of short-course exercise training on the frequency of exacerbations and physical activity in patients with COPD: A randomized controlled trial.

BACKGROUND AND OBJECTIVE: Previous studies have suggested that early pulmonary rehabilitation (PR) programmes post-AECOPD are an effective and safe intervention for reducing hospital admissions and improving quality of life. This study assessed whether a short course of exercise training post-AECOPD with periodic reinforcement exercise training and phone call reminders reduces readmissions and increases physical activity in COPD patients. METHODS: Subjects were randomized into either the (i) intervention group (IG), consisting of 4-8 weeks of training supervised by a physiotherapist and phone contact every 2 weeks by a case manager providing support and reinforcement of continuous exercise at home or (ii) usual care group (UG), which had no input by a physiotherapist or case manager. Readmissions were assessed at 12 months. Activities of all patients were assessed by an activity monitor at baseline, 3 and 12 months. RESULTS: Altogether, 136 subjects were included and randomized (68 in IG and 68 in UG). The age, gender and FEV1 % predicted were 75.0 ± 6.7 years, 132 males and 47.0 ± 16.2%, respectively. The mean number of readmissions for AECOPD (1.06 vs 1.72 times, P = 0.014) was less and time to first readmission was increased (146.8 vs 122.4 days, P = 0.005) in the IG versus UG at 12 months. At 12 months, there was no change in activity measured by activity monitor between the two groups. CONCLUSION: This programme decreased exacerbation frequency and increased the time of readmissions for AECOPD. It did not improve physical activities and exercise tolerance at 12 months.

Environmental fungal sensitisation associates with poorer clinical outcomes in COPD.

INTRODUCTION: Allergic sensitisation to fungi such as Aspergillus are associated to poor clinical outcomes in asthma, bronchiectasis and cystic fibrosis; however, clinical relevance in COPD remains unclear. METHODS: Patients with stable COPD (n=446) and nondiseased controls (n=51) were prospectively recruited across three countries (Singapore, Malaysia and Hong Kong) and screened against a comprehensive allergen panel including house dust mites, pollens, cockroach and fungi. For the first time, using a metagenomics approach, we assessed outdoor and indoor environmental allergen exposure in COPD. We identified key fungi in outdoor air and developed specific-IgE assays against the top culturable fungi, linking sensitisation responses to COPD outcomes. Indoor air and surface allergens were prospectively evaluated by metagenomics in the homes of 11 COPD patients and linked to clinical outcome. RESULTS: High frequencies of sensitisation to a broad range of allergens occur in COPD. Fungal sensitisation associates with frequent exacerbations, and unsupervised clustering reveals a "highly sensitised fungal predominant" subgroup demonstrating significant symptomatology, frequent exacerbations and poor lung function. Outdoor and indoor environments serve as important reservoirs of fungal allergen exposure in COPD and promote a sensitisation response to outdoor air fungi. Indoor (home) environments with high fungal allergens associate with greater COPD symptoms and poorer lung function, illustrating the importance of environmental exposures on clinical outcomes in COPD. CONCLUSION: Fungal sensitisation is prevalent in COPD and associates with frequent exacerbations representing a potential treatable trait. Outdoor and indoor (home) environments represent a key source of fungal allergen exposure, amenable to intervention, in "sensitised" COPD.

Molecular detection of respiratory pathogens and typing of human rhinovirus of adults hospitalized for exacerbation of asthma and chronic obstructive pulmonary disease.

BACKGROUND: Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) and asthma are associated with a variety of precipitating factors including infection. This study assessed the infective viral etiologies by real-time multiplex polymerase chain reaction of patients hospitalized with AECOPD and asthma exacerbations. In addition, infective etiologies were assessed for association with the clinical outcome of the patients. METHODS: Adults admitted with AECOPD and asthma exacerbations between August 2016 and July 2017 were recruited. Nasopharyngeal aspirate (NPA) samples were obtained from the patients within 1-2 days of admission and subjected to pathogen detection and human rhinovirus (HRV) typing. RESULTS: Altogether 402 patients with AECOPD, 80 stable COPD, 100 asthma exacerbation and 21 stable asthma subjects were recruited. Among those admitted for AECOPD and asthma exacerbations, 141(35.1%) and 45(45.0%) respectively had pathogens identified in the NPA specimens. The commonest virus identified was influenza A followed by HRV. HRV typing identified HRV-A and HRV-C as the more common HRV with a wide variety of genotypes. Identification of pathogens in NPA or HRV typing otherwise did not affect clinical outcomes including the hospital length of stay, readmission rates and mortality except that identification of pathogens in asthma exacerbation was associated with a lower rate of readmissions at 30 and 60 days. CONCLUSIONS: Many respiratory viruses were associated with AECOPD and asthma exacerbation. HRV-A and HRV-C were the more common HRV associated with exacerbations. Identification of pathogens in NPA was associated with less readmissions for asthma patients at 30 and 60 days. TRIAL REGISTRATION: ClinicalTrials.gov NCT02866357 .

CC16 levels correlate with cigarette smoke exposure in bronchial epithelial cells and with lung function decline in smokers.

BACKGROUND: Club cell protein-16 (CC16) expression has been associated with smoking-related lung function decline. The study hypothesis was that CC16 expression in both serum and bronchial epithelium is associated with lung function decline in smokers, and exposure to cigarette smoke will lead to reduction in CC16 expression in bronchial epithelial cells. METHODS: In a cohort of community-based male Chinese subjects recruited for lung function test in 2000, we reassessed their lung function ten years later and measured serum levels of CC16. CC16 expression was further assayed in bronchial epithelium from endobronchial biopsies taken from an independent cohort of subjects undergoing autofluorescence bronchoscopy, and tested for correlation between CC16 immunostaining intensity and lung function. In an in-vitro model, bronchial epithelial cells were exposed to cigarette smoke extract (CSE), and the expression levels of CC16 were measured in bronchial epithelial cells before and after exposure to CSE. RESULTS: There was a significant association between FEV1 decline and serum CC16 levels in smokers. Expression of CC16 in bronchial epithelium showed significant correlation with FEV1/FVC. Bronchial epithelial cells showed significant decrease in CC16 expression after exposure to CSE, followed by a subsequent rise in CC16 expression upon removal of CSE. CONCLUSIONS: Results of these clinical and laboratory investigations suggested that low serum CC16 was associated with smoking-related decline in lung function, demonstrated the first time in a Chinese cohort. The data also lend support to the putative role of CC16 in protection against smoking-related bronchial epithelial damage. (Abstract word count: 243) US CLINICAL TRIAL REGISTRY: NCT01185652 , first posted 20 August, 2010.

Genetic effects of multiple asthma loci identified by genomewide association studies on asthma and spirometric indices.

BACKGROUND: Genomewide association study (GWAS) published by GABRIEL consortium identified 10 asthma-associated loci. However, their relationship with lung functions is unclear. This study investigated the association between asthma traits and single-nucleotide polymorphisms (SNPs) of these GWAS loci. METHODS: Rs3894194 and rs9273349 were not genotyped due to unavailable TaqMan assays. Genetic associations of remaining eight SNPs were investigated in 903 school-age asthmatics and 1205 non-allergic controls. Four significant SNPs were then replicated in 479 adult asthmatics and 746 adult controls, and 1341 Chinese preschool children. Meta-analyses were performed by combining data from school-age children and adults. Generalized multifactor dimensionality reduction (GMDR) was used to analyze their interactions for asthma traits. RESULTS: Childhood asthma was associated with GSDMB_rs2305480 (odds ratio [OR] 0.69, 95% confidence interval [CI] 0.57-0.83). IL13_rs1295686 was associated with all asthma (OR 1.64, 95% CI 1.16-2.32) and early-onset asthma (OR 1.92, 95% CI 1.20-3.06) in adults, whereas GSDMB_rs2305480 was only associated with early-onset asthma (OR 0.69, 95% CI 0.49-0.96). According to meta-analyses, the minor allele of rs2305480 was inversely associated with FEV1 , FVC, and FEV1 /FVC (p < 0.01). GMDR analyses revealed 2-locus models of SLC22A5 with SMAD3 to modulate FEVt /FVC in both preschool children and adults, with IL13 to determine FVC in both school-age children and adults, and with IL2RB to modulate FEV1 /FVC in school-age children. CONCLUSIONS: IL13 and GSDMB are replicated as asthma genes. Rs2305480 of GSDMB is also associated with low FEV1 , FVC, and FEV1 /FVC among asthmatics. Moreover, SLC22A5, IL13, SMAD3, and GSDMB interact to modulate spirometric indices.