Gender differences in bronchiectasis: a real issue?

Retrospective cross-sectional study on bronchiectasis in adult Aboriginal Australians: disease characteristics and comparison with ethnically diverse global bronchiectasis registry cohorts

BACKGROUND

Globally, adult Indigenous people, including Aboriginal Australians, have a high burden of chronic respiratory disorders, and bronchiectasis is no exception. However, literature detailing bronchiectasis disease characteristics among adult Indigenous people is sparse. This study assessed the clinical profile of bronchiectasis among adult Aboriginal Australians and compared against previously published international bronchiectasis registry reports.

METHODS

Aboriginal Australians aged >18 years with chest CT confirmed bronchiectasis between 2011 and 2020 in the Top End Northern Territory of Australia were included. Demographics, chest CT findings, pulmonary function results, sputum microbiology, coexistent medical comorbidities, and pharmacotherapy use were assessed and compared against five published international bronchiectasis registry reports (Australian (ABR), European (European Multicentre Bronchiectasis Audit and Research Collaboration (EMBARC)-Europe), Indian (EMBARC-India), Korean (KMBARC) and the USA (USBRR)).

RESULTS

A total of 459 patients were assessed. In comparison with international and non-Aboriginal Australian national cohorts, Aboriginal Australians were younger (median 56 years (IQR (48, 65)); however, sex distribution (55% female) and body mass index (23 kg/m2 (IQR 19.4-27)) were comparable . Smoking rates were higher at 85% compared with other registry cohorts (22-46%) as was the prevalence of comorbidities (97%): cardiovascular diseases (73%), diabetes mellitus (50%) and chronic obstructive pulmonary disease (83%) compared with other registry cohorts (4-32%; 6-14%; and 14-37%, respectively). Spirometry demonstrated forced expiratory volume in 1 s of 38% predicted in comparison with 61-77% in other cohorts. Sputum microbiology showed Haemophilus influenzae (57%) isolated at 3.4 to 6 times the rate of other registry cohorts and Pseudomonas aeruginosa in 31%. Chest CT demonstrated multilobar and lower lobes involvement in 73% and inhaled pharmacotherapy use was recorded in up to 62% and long-term antibiotics in 5%.

CONCLUSION

The overall bronchiectasis disease burden is higher in Aboriginal Australian adults in comparison with global ethnically diverse non-Indigenous populations. Further efforts are required to address this disparity secondary to bronchiectasis among Indigenous people.

Sex-Differences in Alpha-1 Antitrypsin Deficiency: Data From the EARCO Registry

BACKGROUND

Sex and gender influence many aspects of chronic obstructive pulmonary disease (COPD). Limited data are available on this topic in alpha-1 antitrypsin deficiency (AATD). We therefore aimed to investigate sex issues in the EARCO registry, a prospective, international, observational cohort study.

METHODS

Baseline data from PiZZ individuals, enrolled in the registry with complete data on sex and smoking history were analysed by group comparisons and binary logistic regression analyses.

RESULTS

1283 patients with AATD, 49.3% women were analysed. Females reported less tobacco consumption (16.8±12.2 vs. 19.6±14.5 PY, p=0.006), occupational exposures towards gases, dusts or asbestos (p<0.005 each) and consumed less alcohol (5.5±7.6 vs. 8.4±10.3u/week, p<0.001). Females reported COPD (41% vs. 57%, p<0.001) and liver disease (11% vs. 20%, p<0.001) less often. However, they had a higher prevalence of bronchiectasis (24% vs. 13%, p<0.001). Despite better lung function (FEV1%pred. 73.6±29.9 vs. 62.7±29.5, p<0.001) females reported a similar symptom burden (CAT 13.4±9.5 vs. 12.5±8.9, p=ns) and exacerbation frequency (at least one in the previous year 30% vs. 26%, p=ns) compared to males. In multivariate analyses, female sex was an independent risk factor for exacerbations in the previous year OR 1.6 p=0.001 in addition to smoking history, COPD, asthma and bronchiectasis and was also identified as risk factors for symptom burden (CAT≥10) OR 1.4 p=0.014 besides age, BMI, COPD and smoking history.

CONCLUSION

Men had higher rates of COPD and liver disease, women were more likely to have bronchiectasis. Women's higher symptom burden and exacerbation frequency suggest they may need tailored treatment approaches.

Association of short-term exposure to ambient air pollution and temperature with bronchiectasis mortality: a nationwide time-stratified case-crossover study

BACKGROUND

Ambient pollution and non-optimal temperature are major risk factors for respiratory health. However, the relationships between short-term exposure to these factors and bronchiectasis mortality remain unknown.

METHODS

A nationwide, time-stratified case-crossover study across Mainland China was conducted from 2013 to 2019. Records of bronchiectasis deaths were extracted from the National Death Registration Reporting Information System. Daily concentrations of fine particulate matter (PM2.5), coarse particulate matter (PM2.5-10), nitrogen dioxide (NO2), ozone (O3), and daily temperature were obtained from high-resolution prediction models. We utilized conditional logistic regression model and distributed lag nonlinear model to explore the associations of these exposures with bronchiectasis mortality.

FINDINGS

We included a total of 19,320 bronchiectasis deaths. Air pollutant was associated with bronchiectasis mortality within the first 3 days after exposure and the exposure-response relationships were almost linear. An interquartile range increase in PM2.5, PM2.5-10, and O3 was associated with increments of 3.18%, 4.14%, and 4.36% in bronchiectasis mortality at lag 02 d, respectively. Additionally, lower temperature was associated with higher odds of bronchiectasis mortality. Compared to referent temperature (23.6 °C), the odds ratio for bronchiectasis mortality associated with extremely low temperature (P1: -13.4 °C) was 1.54 (95% CI: 1.05, 2.25).

INTERPRETATION

This national study provides compelling evidence, and highlights the necessity and importance of reducing air pollution exposures and keeping warm for susceptible populations.

FUNDING

National Natural Science Foundation of China (81925001; 82330070); Innovation Program of Shanghai Municipal Education Commission (202101070007-E00097); Program of Shanghai Municipal Science and Technology Commission (21DZ2201800); Program of Shanghai Shenkang Development Center (SHDC12023110); and Major Project of National Health Commission of China.

The prevalence and implications of depression and anxiety in patients with bronchiectasis: a systematic review and meta-analysis

Background

Comorbidities significantly affect bronchiectasis prognosis. Depression and anxiety are frequently encountered psychological comorbidities that have the greatest impact on bronchiectasis. This systematic review aimed to identify the prevalence of depression and anxiety and describe their implications for bronchiectasis.

Methods

Three databases were searched from their inception to October 2023 for studies reporting the prevalence and/or clinical implications of depression and anxiety in patients with bronchiectasis. Two independent reviewers rated the quality of the evidence presented in the studies using the risk of bias tool for prevalence studies.

Results

Of the 50 studies identified, 17 studies with 2637 patients were included. The overall risk of bias was classified as low (10 studies) or moderate (seven studies). The pooled prevalence of depression and anxiety was 31% (95% CI 24-38%) and 34% (95% CI 28-40%), respectively. Depression was significantly higher in female compared to male patients (risk difference 10%, 95% CI 0-21%) and associated with bronchiectasis exacerbation (adjusted odds ratio 1.72, 95% CI 1.28-2.15). Depression and anxiety are closely associated with poor health-related quality of life. However, clinical outcomes including dyspnoea symptoms, severity index, computed tomography score, lung function and physical activity were not associated with depression or anxiety.

Conclusion

This study revealed a high prevalence of depression and anxiety among patients with bronchiectasis. Depression was more prevalent in females and is significantly associated with bronchiectasis exacerbation. Depression and anxiety were associated with poor health-related quality of life.

Proteomic approach to identify host cell attachment proteins provides protective Pseudomonas aeruginosa vaccine antigen FtsZ

Pseudomonas aeruginosa is an opportunistic Gram-negative pathogen that causes severe nosocomial infections in susceptible individuals due to the emergence of multidrug-resistant strains. There are no approved vaccines against P. aeruginosa infections nor candidates in active clinical development, highlighting the need for novel candidates and strategies. Using a cell-blot proteomic approach, we reproducibly identified 49 proteins involved in interactions with human lung epithelial cells across four P. aeruginosa strains. Among these were cell division protein FtsZ and outer membrane protein OpmH. Escherichia coli BL21 cells overexpressing recombinant FtsZ or rOpmH showed a 66- and 15-fold increased ability to attach to 16HBE14o- cells, further supporting their involvement in host cell attachment. Both antigens led to proliferation of NK and CD8+ cytotoxic T cells, significant increases in the production of IFN-γ, IL-17A, TNF and IL-4 in immunised mice and elicited strong antigen-specific serological IgG1 and IgG2c responses. Immunisation with FtsZ significantly reduced bacterial burden in the lungs by 1.9-log CFU and dissemination to spleen by 1.8-log CFU. The protective antigen candidate, FtsZ, would not have been identified by traditional approaches relying on either virulence mechanisms or sequence-based predictions, opening new avenues in the development of an anti-P. aeruginosa vaccine.

Sex Differences in Allergic Bronchopulmonary Aspergillosis and its Impact on Exacerbations

The impact of sex on allergic bronchopulmonary aspergillosis (ABPA) outcomes remains uncertain. We retrospectively included ABPA subjects per the revised International Society for Human and Animal Mycology ABPA working group criteria over 13 years. We compared the clinical features, lung function, immunological tests, imaging, and ABPA exacerbation rates between men and women. Our primary objective was to assess whether women experience higher ABPA exacerbations than men. We included 731 ABPA subjects (mean age, 34.5 years; 49.5% women). Women with ABPA were older and had underlying asthma more frequently than men. There was no difference in lung function, immunological investigations, and imaging between men and women. ABPA exacerbations occurred in a slightly higher proportion of women than men (44.5% vs. 38.2%) but did not reach statistical significance (p = 0.09). We did not find a significant sex difference in ABPA exacerbation rates. Prospective studies should confirm our findings.

Exploring the Association of Bacterial Coinfections with Clinical Characteristics of Patients with Nontuberculous Mycobacterial Pulmonary Disease

BACKGROUND

Clinical data for bacterial coinfection of the lower respiratory tract in patients with nontuberculous mycobacterial pulmonary disease (NTM-PD) are scarce. This study aims to assess the prevalence of bacterial coinfection and clinical features in NTM-PD patients.

METHODS

This retrospective study screened 248 patients with NTM-PD who underwent bronchoscopy between July 2020 and July 2022, from whom newly diagnosed NTM-PD patients were analyzed. Bacterial culture using bronchial washing fluid was performed at the time of NTM-PD diagnosis.

RESULTS

In the 180 patients (median age 65 years; 68% female), Mycobacterium avium complex (86%) was the most frequent NTM isolated. Bacterial coinfections were detected in 80 (44%) patients. Among them, the most common bacterium was Klebsiella pneumoniae (n=25/80, 31.3%), followed by Pseudomonas aeruginosa (n=20/80, 25%) and Staphylococcus aureus (n=20/80, 25%). Compared with NTM-PD patients without bacterial coinfections, patients with bacterial coinfections showed more frequent extensive lung involvement (33% vs. 1%, p<0.001). Additionally, compared with NTM-PD patients without P. aeruginosa infection, those with P. aeruginosa infection were older (74 years vs. 64 years, p=0.001), had more frequent respiratory symptoms (cough/excessive mucus production 70% vs. 38%, p=0.008; dyspnea 30% vs. 13%, p=0.047), and had extensive lung involvement (60% vs. 9%, p<0.001).

CONCLUSION

Less than half of patients with newly diagnosed NTM-PD had bacterial coinfections, linked to extensive lung involvement. Specifically, P. aeruginosa coinfection was significantly associated with older age, more frequent respiratory symptoms, and extensive lung involvement.

Clinical Predictors of Nontuberculous Mycobacteria Lung Disease and Coisolates of Potential Pathogenic Microorganisms in Noncystic Fibrosis Bronchiectasis

Background

In bronchiectasis, nontuberculous mycobacteria (NTM) lung disease (NTM-LD) is a well-known coexisting infection. However, microorganism coisolates and clinical NTM-LD predictors are poorly studied.

Methods

Patients with bronchiectasis diagnosed by means of computed tomography between January 2017 and June 2020 were screened, using the date of computed tomography as the index date. Those with a major bronchiectasis diagnosis in ≥2 follow-up visits after the index date were enrolled in the study, and NTM-LD occurrence and its association with pneumonia and hospitalization within 1 year were analyzed.

Results

Of the 2717 participants, 79 (2.9%) had NTM-LD diagnosed. The factors associated with NTM-LD included hemoptysis, postinfectious bronchiectasis, a tree-in-bud score ≥2, a modified Reiff score ≥4, and chronic obstructive pulmonary disease (adjusted odds ratios, 1.80, 2.36, 1.78, 2.95, and 0.51, respectively). Compared with patients in the non-NTM group, those with NTM-LD had higher rates of hospitalization (15.9% vs 32.9%; P < .001) and pneumonia (9.8% vs 20.3%; P = .003). Pseudomonas aeruginosa was the most common microorganism in those with NTM-LD and those in the non-NTM group (10.1% vs 7.8%; P = .40). However, compared with those in the non-NTM group, Acinetobacter baumannii and Escherichia coli were more prevalent in patients with NTM-LD (0.7% vs 3.8% [P = .03%] and 1.0% vs 3.8% [P = .05], respectively).

Conclusions

Postinfectious bronchiectasis with hemoptysis, higher radiological involvement, and a tree-in-bud pattern were associated with NTM-LD risk. The rate of A baumannii and E coli coisolation was higher in bronchiectasis populations with NTM-LD.

Sex differences in airway disease: estrogen and airway surface liquid dynamics

Biological sex differences exist for many airway diseases in which females have either worse or better health outcomes. Inflammatory airway diseases such as cystic fibrosis (CF) and asthma display a clear male advantage in post-puberty while a female benefit is observed in asthma during the pre-puberty years. The influence of menstrual cycle stage and pregnancy on the frequency and severity of pulmonary exacerbations in CF and asthma point to a role for sex steroid hormones, particularly estrogen, in underpinning biological sex differences in these diseases. There are many ways by which estrogen may aggravate asthma and CF involving disturbances in airway surface liquid (ASL) dynamics, inappropriate hyper-immune and allergenic responses, as well as exacerbation of pathogen virulence. The deleterious effect of estrogen on pulmonary function in CF and asthma contrasts with the female advantage observed in airway diseases characterised by pulmonary edema such as pneumonia, acute respiratory distress syndrome (ARDS) and COVID-19. Airway surface liquid hypersecretion and alveolar flooding are hallmarks of ARDS and COVID-19, and contribute to the morbidity and mortality of severe forms of these diseases. ASL dynamics encompasses the intrinsic features of the thin lining of fluid covering the airway epithelium which regulate mucociliary clearance (ciliary beat, ASL height, volume, pH, viscosity, mucins, and channel activating proteases) in addition to innate defence mechanisms (pathogen virulence, cytokines, defensins, specialised pro-resolution lipid mediators, and metabolism). Estrogen regulation of ASL dynamics contributing to biological sex differences in CF, asthma and COVID-19 is a major focus of this review.

Phenotype and Clinicoradiological Differences in Multifocal and Focal Bronchiectasis

Introduction: Bronchiectasis is a chronic progressive respiratory disease characterized by permanent dilatation of the bronchi. It is a complex condition with numerous different etiologies, co-morbidities, and a heterogeneous presentation. As we know, there is a lack of studies that describe the differences and compare the characteristics between focal and multifocal bronchiectasis. The aim of this study is to identify differences in clinical characteristics presentation, severity or distribution in focal and multifocal bronchiectasis, and prognostic implications. Methods: 126 patients with computed tomography (CT)-verified bronchiectasis were enrolled. Baseline characteristics that included age, sex, smoking history, and respiratory symptoms were recorded, with special attention paid to hemoptysis appearance, body mass index, and comorbidities. The type of bronchiectasis determined by CT scan and the modified Reiff scores indicating radiological severity were recorded. Patients were divided in two groups (I is focal and II is multifocal). Results: There were no statistically significant differences in age, smoking status, comorbidity, and BMI between the two groups. Multifocality was associated with a significantly higher proportion of females (p = 0.014), the rate of hemoptysis (p = 0.023), and the number of hospitalizations, but not of exacerbations and prevalence of immunodeficiency (p = 0.049). Significantly, a high number of subjects with multifocality had bronchiectasis of moderate severity, and post-infective and asthma-associated phenotypes were the dominant in this group. Unexpectedly, the cystic and varicose radiological phenotype (which need more time to develop) were more dominant in the focal group. The cylindrical phenotype was equally observed in the multifocal and focal groups. Conclusions: Our study suggests that multifocality is not related to age, number of exacerbations, or radiological phenotype, but it seems to be associated with the clinical post-infective phenotype, immunodeficiency, frequent hospitalizations, and severity. Thus, the presence of multifocal bronchiectasis may act as a biomarker of severity and poor outcomes in these patients.

Accelerated elastin degradation by age-disease interaction: a common feature in age-related diseases

Aging is a major driving force for many diseases but the relationship between chronological age, the aging process and age-related diseases is not fully understood. Fragmentation and loss of ultra-long-lived elastin are key features in aging and several age-related diseases leading to increased mortality. By comparing the relationship between age and elastin turnover with healthy volunteers, we show that accelerated elastin turnover by age-disease interaction is a common feature of age-related diseases.

Gender differences in clinical characteristics of patients with non-cystic fibrosis bronchiectasis in different age groups in northern China

INTRODUCTION

Patient gender has clinical and prognostic implications in non-cystic fibrosis bronchiectasis, yet the potential effect of gender on clinical characteristics of patients with non-cystic fibrosis bronchiectasis is still unclear.

OBJECTIVES

This study aimed to investigate the gender differences in clinical characteristics of patients with bronchiectasis in different age groups in northern China.

METHODS

A total of 777 patients diagnosed with bronchiectasis were retrospectively included in Beijing Chaoyang Hospital and divided into two groups by gender: the male group and the female group. Each group was then subdivided into two according to their age (≤65 and >65 years). Gender differences in clinical characteristics were compared in all patients with bronchiectasis in the two age groups, respectively.

RESULTS

A total of 777 bronchiectasis patients were included. Of these patients, the prevalence of female non-smokers was substantially higher than that of male non-smokers (94.0% vs. 36.8%). There were gender differences in etiology of bronchiectasis, with more post-measles and connective tissue disease in females (p = 0.006 and 0.002 separately) and more chronic obstructive pulmonary disease (COPD) in males (p < 0.001). The male group had a significantly higher C-reactive protein (CRP) on admission (p = 0.03). Female patients showed a higher forced expiratory volume in 1 s as percentage of predicted volume (FEV1%pred) and forced vital capacity rate of 1 s (FEV1/FVC) (p < 0.001), lower partial pressure of carbon dioxide (PaCO₂ ) (p = 0.04) and hospital costs (p = 0.02) than males, and a higher prevalence of infection with Pseudomonas aeruginosa in >65-year-old group (p = 0.019).

CONCLUSIONS

There were many differences between male and female patients in smoking status, etiology, lung function, blood gas analysis, and hospital costs in all patients or different age groups.

Sex and Gender in Lung Diseases and Sleep Disorders: A State-of-the-Art Review: Part 2

There is now ample evidence that differences in sex and gender contribute to the incidence, susceptibility, presentation, diagnosis, and clinical course of many lung diseases. Some conditions are more prevalent in women, such as pulmonary arterial hypertension and sarcoidosis. Some life stages-such as pregnancy-are unique to women and can affect the onset and course of lung disease. Clinical presentation may differ as well, such as the higher number of exacerbations experienced by women with cystic fibrosis (CF), more fatigue in women with sarcoidosis, and more difficulty in achieving smoking cessation. Outcomes such as mortality may be different as well, as indicated by the higher mortality in women with CF. In addition, response to therapy and medication safety may also differ by sex, and yet, pharmacogenomic factors are often not adequately addressed in clinical trials. Various aspects of lung/sleep biology and pathobiology are impacted by female sex and female reproductive transitions. Differential gene expression or organ development can be impacted by these biological differences. Understanding these differences is the first step in moving toward precision medicine for all patients. This article is the second part of a state-of-the-art review of specific effects of sex and gender focused on epidemiology, disease presentation, risk factors, and management of selected lung diseases. We review the more recent literature and focus on guidelines incorporating sex and gender differences in pulmonary hypertension, CF and non-CF bronchiectasis, sarcoidosis, restless legs syndrome and insomnia, and critical illness. We also provide a summary of the effects of pregnancy on lung diseases and discuss the impact of sex and gender on tobacco use and treatment of nicotine use disorder.

Sex and Gender Differences in Tuberculosis Pathogenesis and Treatment Outcomes

Tuberculosis remains a daunting public health concern in many countries of the world. A consistent observation in the global epidemiology of tuberculosis is an excess of cases of active pulmonary tuberculosis among males compared with females. Data from both humans and animals also suggest that males are more susceptible than females to develop active pulmonary disease. Similarly, male sex has been associated with poor treatment outcomes. Despite this growing body of evidence, little is known about the mechanisms driving sex bias in tuberculosis disease. Two dominant hypotheses have been proposed to explain the predominance of active pulmonary tuberculosis among males. The first is based on the contribution of biological factors, such as sex hormones and genetic factors, on host immunity during tuberculosis. The second is focused on non-biological factors such as smoking, professional exposure, and health-seeking behaviors, known to be influenced by gender. In this chapter, we review the literature regarding these two prevailing hypotheses by presenting human but also experimental animal studies. In addition, we presented studies aiming at examining the impact of sex and gender on other clinical forms of tuberculosis such as latent tuberculosis infection and extrapulmonary tuberculosis, which both appear to have their own specificities in relation to sex. We also highlighted potential intersections between sex and gender in the context of tuberculosis and shared future directions that could guide in elucidating mechanisms of sex-based differences in tuberculosis pathogenesis and treatment outcomes.

Association between non-cystic fibrosis bronchiectasis and the risk of incident dementia: A nationwide cohort study

BACKGROUND

Chronic lung diseases, such as chronic obstructive pulmonary disease or asthma, are associated with an increased risk of dementia. However, few data are available regarding the risk of dementia in individuals with bronchiectasis.

OBJECTIVES

To explore the association between bronchiectasis and the risk of incident dementia using a longitudinal population-based cohort.

METHODS

A total of 4,068,560 adults older than 50 years without previous dementia were enrolled from the Korean National Health Insurance Service database in 2009. They were followed up until the date of the diagnosis of dementia or December 31, 2020. The study exposure was the diagnosis of bronchiectasis, and the primary outcome was incident dementia comprising Alzheimer's disease and vascular dementia.

RESULTS

During the median follow-up duration of 9.3 years, the incidence of all-cause dementia was 1.6-fold higher in individuals with bronchiectasis than in those without bronchiectasis (15.0 vs. 9.3/1000 person-years, p < .001). In the multivariable Cox regression analysis, the risk of all dementia was significantly higher in individuals with bronchiectasis than in those without bronchiectasis (adjusted hazard ratio [aHR] 1.09, 95% confidence interval [CI] 1.04-1.14). In a subgroup analysis by dementia type, individuals with bronchiectasis had an increased risk of Alzheimer's disease compared to those without bronchiectasis (aHR 1.07, 95% CI 1.01-1.12); the risk of vascular dementia did not significantly differ between the two groups (aHR 1.05, 95% CI 0.90-1.21).

CONCLUSION

Bronchiectasis was associated with an increased risk of dementia, especially Alzheimer's disease.

Impact of Acute Exacerbation and Its Phenotypes on the Clinical Outcomes of Chronic Obstructive Pulmonary Disease in Hospitalized Patients: A Cross-Sectional Study

Acute exacerbations of COPD (AECOPD) are clinically significant events having therapeutic and prognostic consequences. However, there is a lot of variation in its clinical manifestations described by phenotypes. The phenotypes of AECOPD were categorized in this study based on pathology and exposure. In our cross-sectional study, conducted between 1 January 2016 to 31 December 2020, the patients were categorized into six groups based on pathology: non-bacterial and non-eosinophilic; bacterial; eosinophilic; bacterial infection with eosinophilia; pneumonia; and bronchiectasis. Further, four groups were classified based on exposure to tobacco smoke (TS), biomass smoke (BMS), both, or no exposure. Cox proportional-hazards regression analyses were performed to assess hazard ratios, and Kaplan-Meier analysis was performed to assess survival, which was then compared using the log-rank test. The odds ratio (OR) and independent predictors of ward admission type and length of hospital stay were assessed using binomial logistic regression analyses. Of the 2236 subjects, 2194 were selected. The median age of the cohort was 67.0 (60.0 to 74.0) and 75.2% were males. Mortality rates were higher in females than in males (6.2% vs. 2.3%). AECOPD-B (bacterial infection) subjects [HR 95% CI 6.42 (3.06-13.46)], followed by AECOPD-P (pneumonia) subjects [HR (95% CI: 4.33 (2.01-9.30)], were at higher mortality risk and had a more extended hospital stay (6.0 (4.0 to 9.5) days; 6.0 (4.0 to 10.0). Subjects with TS and BMS-AECOPD [HR 95% CI 7.24 (1.53-34.29)], followed by BMS-AECOPD [HR 95% CI 5.28 (2.46-11.35)], had higher mortality risk. Different phenotypes have different impacts on AECOPD clinical outcomes. A better understanding of AECOPD phenotypes could contribute to developing an algorithm for the precise management of different phenotypes.

Genome sequencing reveals underdiagnosis of primary ciliary dyskinesia in bronchiectasis

BACKGROUND

Bronchiectasis can result from infectious, genetic, immunological and allergic causes. 60-80% of cases are idiopathic, but a well-recognised genetic cause is the motile ciliopathy, primary ciliary dyskinesia (PCD). Diagnosis of PCD has management implications including addressing comorbidities, implementing genetic and fertility counselling and future access to PCD-specific treatments. Diagnostic testing can be complex; however, PCD genetic testing is moving rapidly from research into clinical diagnostics and would confirm the cause of bronchiectasis.

METHODS

This observational study used genetic data from severe bronchiectasis patients recruited to the UK 100,000 Genomes Project and patients referred for gene panel testing within a tertiary respiratory hospital. Patients referred for genetic testing due to clinical suspicion of PCD were excluded from both analyses. Data were accessed from the British Thoracic Society audit, to investigate whether motile ciliopathies are underdiagnosed in people with bronchiectasis in the UK.

RESULTS

Pathogenic or likely pathogenic variants were identified in motile ciliopathy genes in 17 (12%) out of 142 individuals by whole-genome sequencing. Similarly, in a single centre with access to pathological diagnostic facilities, 5-10% of patients received a PCD diagnosis by gene panel, often linked to normal/inconclusive nasal nitric oxide and cilia functional test results. In 4898 audited patients with bronchiectasis, <2% were tested for PCD and <1% received genetic testing.

CONCLUSIONS

PCD is underdiagnosed as a cause of bronchiectasis. Increased uptake of genetic testing may help to identify bronchiectasis due to motile ciliopathies and ensure appropriate management.

Prenatal pyrethroid exposure and lung function among school-aged children

BACKGROUND

Previous epidemiological evidence mainly focused on the adverse effects of prenatal exposure to pyrethroid insecticides (PYRs) on respiratory health during childhood. It remains unclear whether the PYR exposures can also impact on children's lung function.

OBJECTIVES

To explore the potential effects of prenatal PYR exposures on lung function in a population of Chinese children.

METHODS

This study included 233 mother-child dyads from the Laizhou Wan Birth Cohort (LWBC), Shandong province, northern China, between September 2010 and December 2013. Three metabolites of PYRs [3-phenoxybenzoic acid (3-PBA), and cis- and trans-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (cis-DCCA and trans-DCCA)] were measured using gas chromatography-mass spectrometry (GC-MS) in maternal urine samples collected at recruitment. Lung function was assessed with spirometry in children aged 6-8 years. Multivariable linear regression and generalized linear models (GLMs) assessed the associations of prenatal PYR exposures with lung function in children.

RESULTS

Among the PYR metabolites, 3-PBA (81.5%) were most frequently detected, followed by trans-DCCA (55.4%) and cis-DCCA (21.9%). The 3-PBA concentration was associated with a 1% decrease in FEV₁/FVC in the highest quartiles of exposure compared to the lowest quartile, with a potential dose response association (p-trend = 0.085). Our findings provide a suggestive effect modification by sex, with girls being more susceptible than the boys (p-trend = 0.011). However, there were no associations between the trans-DCCA concentration and lung function parameters.

CONCLUSION

Prenatal 3-PBA concentrations were associated with a modest decrease in FEV₁/FVC among school-aged children, and the association was slightly more pronounced for the girls than for the boys.

Effects of the Sex Steroid Hormone Estradiol on Biofilm Growth of Cystic Fibrosis Pseudomonas aeruginosa Isolates

Women with cystic fibrosis (CF) have a significantly lower life expectancy compared to men, which is indicated by an earlier impairment of lung function due to chronic colonization with biofilm formed by Pseudomonas aeruginosa. There is growing evidence that blood serum concentrations of the steroid sex hormone estradiol (E₂) correlate with the occurrence of pulmonary exacerbations in CF but also play a role in the mucoid switch of P. aeruginosa. This study aims to shed light on possible microbiological reasons for sexual dimorphism in CF by investigating the influence of E₂ on biofilm formation of P. aeruginosa CF isolates. For this purpose, 10 CF isolates of the respiratory tract derived from different CF patients have been treated with E₂ in a microtiter plate biofilm model. Biofilms have been examined by crystal violet assays, field emission scanning electron microscopy (FE-SEM), 3D laser scanning microscopy (LSM), and quorum sensing (QS) reporter assays of the supernatants taken from biofilms. This allowed us to simultaneously investigate the effects of E₂ on attached biofilm mass, biofilm ultrastructure, and QS activity. Upon E₂ treatment, six out of 10 investigated CF isolates showed an increase of attached biofilm mass, whereas biofilms from two tested non-CF laboratory strains (PAO1 and ATCC19660) did not. Moreover, FE-SEM and 3D LSM analyses of the E₂ responsive CF biofilms revealed ultrastructural remodeling of biofilm structure at different scales with increased formation of prominent biofilm spots, enhanced coverage with extracellular polymeric substance (EPS), and extended average surface roughness. QS activity measurements performed in biofilm supernatants via luminescence acyl homoserine lactone (AHL) reporter assays further showed that E₂ treatment may also modulate QS signaling, as shown in an E₂ sensitive CF isolate. Together, our results suggest the biofilm modulating effects of E₂ on various clinical CF isolates that are documented by both biomass and ultrastructural changes of biofilms. The gained new insight into the influence of steroid hormones on P. aeruginosa biofilm phenotypes might pave the way for novel future approaches in personalized medicine based on the patients’ sex and hormonal status.

CF Patients’ Airway Epithelium and Sex Contribute to Biosynthesis Defects of Pro-Resolving Lipids

Specialized pro-resolving lipid mediators (SPMs) as lipoxins (LX), resolvins (Rv), protectins (PD) and maresins (MaR) promote the resolution of inflammation. We and others previously reported reduced levels of LXA4 in bronchoalveolar lavages from cystic fibrosis (CF) patients. Here, we investigated the role of CF airway epithelium in SPMs biosynthesis, and we evaluated its sex specificity. Human nasal epithelial cells (hNEC) were obtained from women and men with or without CF. Lipids were quantified by mass spectrometry in the culture medium of hNEC grown at air-liquid interface and the expression level and localization of the main enzymes of SPMs biosynthesis were assessed. The 5-HETE, LXA4, LXB4, RvD2, RvD5, PD1 and RvE3 levels were significantly lower in samples derived from CF patients compared with non-CF subjects. Within CF samples, the 12-HETE, 15-HETE, RvD3, RvD4, 17-HODHE and PD1 were significantly lower in samples derived from females. While the mean expression levels of 15-LO, 5-LO and 12-LO do not significantly differ either between CF and non-CF or between female and male samples, the SPMs content correlates with the level of expression of several enzymes involved in SPMs metabolism. In addition, the 5-LO localization significantly differed from cytoplasmic in non-CF to nucleic (or nuclear envelope) in CF hNEC. Our studies provided evidence for lower abilities of airway epithelial cells derived from CF patients and more markedly, females to produce SPMs. These data are consistent with a contribution of CF airway epithelium in the abnormal resolution of inflammation and with worse pulmonary outcomes in women.

Association between Smoking Status and Incident Non-Cystic Fibrosis Bronchiectasis in Young Adults: A Nationwide Population-Based Study

Smoking traditionally has not been considered as a cause of bronchiectasis. However, few studies have evaluated the association between smoking and bronchiectasis. This study aimed to investigate the association between smoking status and bronchiectasis development in young adults. This study included 6,861,282 adults aged 20−39 years from the Korean National Health Insurance Service database 2009−2012 who were followed-up until the date of development of bronchiectasis, death, or 31 December 2018. We evaluated the incidence of bronchiectasis according to smoking status. During a mean of 7.4 years of follow-up, 23,609 (0.3%) participants developed bronchiectasis. In multivariable Cox regression analysis, ex-smokers (adjusted hazard ratio (aHR) = 1.07, 95% confidence interval (CI) = 1.03−1.13) and current-smokers (aHR = 1.06, 95% CI = 1.02−1.10) were associated with incident bronchiectasis, with the highest HR in ≥ 10 pack-years current smokers (aHR = 1.12, 95% CI = 1.06−1.16). The association of smoking with bronchiectasis was more profound in females than in males (p for interaction < 0.001), in younger than in older participants (p for interaction = 0.036), and in the overweight and obese than in the normal weight or underweight (p for interaction = 0.023). In conclusion, our study shows that smoking is associated with incident bronchiectasis in young adults. The association of smoking with bronchiectasis development was stronger in females, 20−29 year-olds, and the overweight and obese than in males, 30−40-year-olds, and the normal weight or underweight, respectively.

Just breathe: a review of sex and gender in chronic lung disease

Chronic lung diseases are the third leading cause of death worldwide and are increasing in prevalence over time. Although much of our traditional understanding of health and disease is derived from study of the male of the species - be it animal or human - there is increasing evidence that sex and gender contribute to differences in disease risk, prevalence, presentation, severity, treatment approach, response and outcomes. Chronic obstructive pulmonary disease, asthma and bronchiectasis represent the most prevalent and studied chronic lung diseases and have key sex- and gender-based differences which are critical to consider and incorporate into clinical and research approaches. Mechanistic differences present opportunities for therapeutic development whereas behavioural and clinical differences on the part of patients and providers present opportunities for greater education and understanding at multiple levels. In this review, we seek to summarise the sex- and gender-based differences in key chronic lung diseases and outline the clinical and research implications for stakeholders.

Respiratory and Peripheral Muscle Weakness and Body Composition Abnormalities in Non-Cystic Fibrosis Bronchiectasis Patients: Gender Differences

As demonstrated in COPD, bronchiectasis patients may experience respiratory and peripheral muscle dysfunction. We hypothesized that respiratory and peripheral (upper and lower limbs) muscle function and nutritional status may be more significantly altered in female than in males for identical age and disease severity. In mild-to-moderate bronchiectasis patients (n = 150, 114 females) and 37 controls (n = 37, 21 females), radiological extension, maximal inspiratory and expiratory pressures (MIP and MEP), sniff nasal inspiratory pressure (SNIP), hand grip and quadriceps muscle strengths, body composition, and blood analytical biomarkers were explored. Compared to the controls, in all bronchiectasis patients (males and females), BMI, fat-free mass index (FFMI), fat tissue, upper and lower limb muscle strength, and respiratory muscle strength significantly declined, and FFMI, fat tissue, and quadriceps muscle function were significantly lower in female than male patients. In patients with mild-to-moderate bronchiectasis, respiratory and peripheral muscle function is significantly impaired and only partly related to lung disease status. Quadriceps muscle strength was particularly weakened in the female patients and was negatively associated with their exercise tolerance. Muscle weakness should be therapeutically targeted in bronchiectasis patients. Body composition and peripheral muscle function determination should be part of the comprehensive clinical assessment of these patients.

Female Reproductive Factors and the Risk of Bronchiectasis: A Nationwide Population-Based Longitudinal Study

Although the oestrogen level is thought to be involved in the occurrence of bronchiectasis, limited data are available on the relationship between female reproductive factors and the risk of bronchiectasis. We performed a population-based retrospective cohort study of 959,523 premenopausal women and 1,362,401 postmenopausal women without a previous history of bronchiectasis who participated in a health screening exam in 2009 in South Korea. In premenopausal women, compared with a later age at menarche (≥16 years), an earlier menarche (<12 years) was associated with a reduced risk of bronchiectasis with an adjusted hazard ratio (aHR) (95% confidence interval (CI)) of 0.74 (0.67–0.81). However, there were no significant associations between other reproductive factors (breastfeeding, parity, or oral contraceptive use) and the risk of bronchiectasis. In postmenopausal women, the risk of bronchiectasis (aHR (95% CI)) was lower in those with an earlier menarche (0.79 (0.72–0.87) for <12 years vs. ≥16 years), a later menopause (0.90 (0.84–0.96) ≥55 years vs. <40 years), and a longer reproductive period (0.90 (0.86–0.94) for ≥40 years vs. <30 years). There was no significant relationship between parity and the risk of bronchiectasis. Although breastfeeding <1 year (aHR (95% CI) = 0.92 (0.87–0.97) for <0.5 years and 0.93 (0.88–0.97) for 0.5–1 years) and oral contraceptive use <1 year (0.97 (0.94–0.99)) reduced the risk of bronchiectasis, hormone replacement therapy ≥5 years increased the risk of bronchiectasis (1.24 (1.18–1.30)). Female reproductive factors are risk factors for developing bronchiectasis, showing a higher risk associated with shorter endogenous oestrogen exposure regardless of the menopausal status.

Breath analysis using electronic nose and gas chromatography-mass spectrometry: A pilot study on bronchial infections in bronchiectasis

BACKGROUND AND AIMS

In this work, breath samples from clinically stable bronchiectasis patients with and without bronchial infections by Pseudomonas Aeruginosa- PA) were collected and chemically analysed to determine if they have clinical value in the monitoring of these patients.

MATERIALS AND METHODS

A cohort was recruited inviting bronchiectasis patients (25) and controls (9). Among the former group, 12 members were suffering PA infection. Breath samples were collected in Tedlar bags and analyzed by e-nose and Gas Chromatography-Mass Spectrometry (GC-MS). The obtained data were analyzed by chemometric methods to determine their discriminant power in regards to their health condition. Results were evaluated with blind samples.

RESULTS

Breath analysis by electronic nose successfully separated the three groups with an overall classification rate of 84% for the three-class classification problem. The best discrimination was obtained between control and bronchiectasis with PA infection samples 100% (CI_95%: 84-100%) on external validation and the results were confirmed by permutation tests. The discrimination analysis by GC-MS provided good results but did not reach proper statistical significance after a permutation test.

CONCLUSIONS

Breath sample analysis by electronic nose followed by proper predictive models successfully differentiated between control, Bronchiectasis and Bronchiectasis PA samples.

Sputum procalcitonin: a potential biomarker in stable bronchiectasis

Sputum procalcitonin is elevated in exacerbations of bronchiectasis. The primary aim of this study was to investigate whether sputum procalcitonin levels are higher in patients with stable bronchiectasis than in healthy controls. We also assessed differences in procalcitonin levels in spontaneously expectorated and induced sputum samples and their repeatability 1 week later.

Participants included were aged over 18 years and either had radiologically confirmed bronchiectasis or were healthy controls. Patients with bronchiectasis were clinically stable for at least 6 weeks and had spontaneous and induced sputum collected at visit 1 and again 7 days later. Only induced sputum samples were collected from healthy controls during visit 1. Sputum procalcitonin concentrations in sputum were measured.

In total, 30 patients with bronchiectasis and 15 healthy controls were enrolled in this observational study. In the pooled data from visit 1 and 2, the geometric mean procalcitonin level in induced sputum was significantly higher in the bronchiectasis group than in the healthy control group (1.5 ng·mL⁻¹, 95% CI 1.0–2.1 ng·mL⁻¹versus 0.4 ng·mL⁻¹, 95% CI 0.2–0.9 ng·mL⁻¹; mean ratio 3.6, 95% CI 1.5–8.6; p=0.006). Mean procalcitonin level was higher in spontaneous sputum than in induced sputum at visit 1 (1.8 ng·mL⁻¹, 95% CI 1.2–2.7 ng·mL⁻¹versus 1.1 ng·mL⁻¹, 95% CI 0.7–1.8 ng·mL⁻¹) and visit 2 (1.5 ng·mL⁻¹, 95% CI 1.0–2.5 ng·mL⁻¹versus 1.2 ng·mL⁻¹, 95% CI 0.8–1.6 ng·mL⁻¹; p=0.001). Repeating spontaneous and induced sputum procalcitonin levels 1 week later produced similar concentrations (p=0.29, intraclass correlation coefficient (ICC)=0.76 and p=0.72, ICC=0.70, respectively).

Sputum procalcitonin is increased in patients with stable bronchiectasis and has potential as a biomarker of airway inflammation and infection in bronchiectasis.

Sputum procalcitonin levels are higher in patients with stable bronchiectasis than in healthy controls. Sputum procalcitonin has the potential to be a biomarker of airway inflammation and infection in bronchiectasis.https://bit.ly/3ivn7R9

Gender differences in non-cystic fibrosis bronchiectasis severity and bacterial load: the potential role of hormones

Non cystic-fibrosis bronchiectasis (NCFB) is a complex chronic respiratory disease, characterised by excessive sputum production and abnormal permanent dilation of bronchi. Mucus accumulation leads to recurrent bacterial infections and increased bacterial load, causing vicious cycles of structural damage and decreased lung function. Respiratory physiotherapy management of NCFB includes airway clearance techniques and use of nebulised, hypertonic saline. Despite advances in treatment, a consistent relationship has been observed between gender and disease occurrence, with a higher prevalence amongst females. Furthermore, NCFB presents most aggressively amongst post-menopausal females, a group likely exposed to higher levels of progesterone (P4) over a longer period of time. The effects of gender-specific hormones on bacterial load and physiotherapy management of people living with NCFB remain unknown. The aim of this narrative review was to discuss the potential influence of gender specific hormones on NCFB disease progression and influence on physiotherapy, medical management and future research. SCOPUS and PUBMED electronic databases were used to conduct searches for relevant studies using specific inclusion and exclusion criteria. Secondary inclusion of relevant literature was obtained from primary paper references. Previous literature suggests that P4 may impair Cilia Beat Frequency (CBF) in airway epithelium. Reduction in CBF may further reduce ability to expectorate amongst individuals with NCFB, increasing bacterial load and likelihood of exacerbations, negatively impacting on disease progression. Furthermore, coadministration of Estrogen has been suggested to offer opposing effects to that of P4 only. These findings question whether hormonal levels may be monitored, controlled and optimised within management and treatment of females with NCFB to improve airway clearance, reduce exacerbations and improve quality of life. Larger scale, long-term trials are required to further explore the effects of gender specific hormones on NCFB and the viability of treatment with hormone replacement therapy.

The reviews of this paper are available via the supplemental material section.

Being Underweight Increases the Risk of Non-Cystic Fibrosis Bronchiectasis in the Young Population: A Nationwide Population-Based Study

Although body mass index (BMI) is a potential risk factor for bronchiectasis in young adults, the association between BMI and incident bronchiectasis has not been well elucidated. This study included 6,329,838 individuals aged 20-40 years from the Korean National Health Insurance Service database 2009-2012 who were followed up until the date of the diagnosis of bronchiectasis, death, or 31 December 2018. We evaluated the incidence and risk of bronchiectasis according to the BMI category. The incidence rate of bronchiectasis increased as BMI decreased in a dose-dependent manner (p for trend <0.01). In multivariable Cox regression analysis, being underweight was an independent risk factor for the development of bronchiectasis, with a hazard ratio of 1.24 (95% confidence interval, 1.19-1.30) compared to being normal weight. In subgroup analysis, the effect of being underweight on the development of bronchiectasis was more evident in males and older individuals (30-40 years) than females and younger individuals (20-29 years), respectively (p for interaction <0.01 for both). These results remained significant in subgroup analysis in which subjects with comorbidities related to being underweight were excluded. Being underweight may be a novel risk factor for the development of bronchiectasis in young adults.

Evaluating the Prevalence and Incidence of Bronchiectasis and Nontuberculous Mycobacteria in South Korea Using the Nationwide Population Data

Although the prevalence and incidence of bronchiectasis are rising worldwide, basic epidemiologic data have not been reported in Korea. Therefore, this study was conducted to investigate epidemiological characteristics of bronchiectasis and NTM (nontuberculous mycobacteria) pulmonary diseases in Korea using the National Health Insurance Service-National Sample Cohort (NHIS-NSC) data. The relative risks of prevalence and incidence after adjusting for demographic characteristics were evaluated by multivariate Poisson regression. The result of this study showed the prevalence and incidence rates of bronchiectasis and NTM to be epidemiologically similar to each other with a few slight differences, while the prevalence rate of bronchiectasis was not significantly different by gender, and its incidence rate was significantly lower in women than in men. Both the prevalence and incidence of NTM were significantly higher in women than in men. Both the prevalence and incidence rates of bronchiectasis and NTM were significantly lower in the age group below 40–49 years, and significantly higher in the age groups thereafter. As there were gender differences of bronchiectasis and NTM, gender-sensitive risk management should be available. In addition, since both bronchiectasis and NTM increase in prevalence and incidence after the age of 40–49, early detection and intervention strategies targeting the appropriate age group are needed.

Prevalence of asymptomatic bronchiectasis and associations among the health screening population in South Korea

Despite the burden of bronchiectasis, there is little data from South Korea regarding asymptomatic bronchiectasis. We aimed to investigate the prevalence of bronchiectasis based on computed tomography (CT) findings, with emphasis on asymptomatic bronchiectasis (CT-proven) and its related factors. We analysed data of individuals who underwent chest CT at a South Korean health screening centre from 2016 to 2017. The prevalence of bronchiectasis was evaluated and adjusted by sex, age, and corresponding year for the Korean general population. Logistic regression analysis was performed to identify factors related to asymptomatic bronchiectasis by comparison between a group without bronchiectasis and a group with symptomatic bronchiectasis. Among the 27 617 subjects screened, 1005 were diagnosed with bronchiectasis based on CT findings, representing an adjusted prevalence of 2329 out of 100 000. The adjusted prevalence of asymptomatic bronchiectasis was 1235 out of 100 000, and that of symptomatic bronchiectasis was 1094 out of 100 000. Compared with the non-bronchiectasis group, the factors related to asymptomatic bronchiectasis were female sex (OR 1.41; 95% CI 1.18-1.70), older age (OR 1.06; 95% CI 1.05-1.07), comorbid liver disease (OR 1.32; 95% CI 1.07-1.63) or COPD (OR 4.99; 95% CI 2.88-8.64), history of tuberculosis (OR 1.98; 95% CI 1.46-2.68) and low forced expiratory volume in 1 s (FEV₁; OR 0.99; 95% CI 0.98-0.998). In South Korea, the prevalence of asymptomatic bronchiectasis appeared higher than that of symptomatic bronchiectasis. Female sex, older age, liver disease, COPD, history of tuberculosis and low FEV₁ may be the factors related to asymptomatic bronchiectasis.

Heterogeneity of non-cystic-fibrosis bronchiectasis in multiethnic Singapore: A prospective cohort study at a tertiary pulmonology centre

Introduction: Non-cystic fibrosis bronchiectasis (NCFB) is a highly heterogenous disease. We describe the clinical characteristics of NCFB patients and evaluate the performance of Bronchiectasis Severity Index (BSI) in predicting mortality. Methods: Patients attending the bronchiectasis clinic between August 2015 and April 2020 with radiologically proven bronchiectasis on computed tomography were recruited. Clinical characteristics, spirometry, radiology, microbiology and clinical course over a median period of 2.4 years is presented. Results: A total of 168 patients were enrolled in this prospective cohort study. They were predominantly women (67.8%), Chinese (87.5%) and never-smokers (76.9%). Median age of diagnosis was 64 years (interquartile range 56–71) and the most common aetiology was “idiopathic” bronchiectasis (44.6%). Thirty-nine percent had normal spirometries. Compared to female patients, there were more smokers among the male patients (53.8% versus 8.5%, P<0.001) and a significantly larger proportion with post-tuberculous bronchiectasis (37.0% vs 15.8%, P=0.002). Fifty-five percent of our cohort had a history of haemoptysis. Lower body mass index, presence of chronic obstructive pulmonary disease, ever-smoker status, modified Reiff score, radiological severity and history of exacerbations were risk factors for mortality. Survival was significantly shorter in patients with severe bronchiectasis (BSI>9) compared to those with mild or moderate disease (BSI<9). The hazard ratio for severe disease (BSI>9) compared to mild disease (BSI 0–4) was 14.8 (confidence interval 1.929–114.235, P=0.01). Conclusion: The NCFB cohort in Singapore has unique characteristics with sex differences. Over half the patients had a history of haemoptysis. The BSI score is a useful predictor of mortality in our population. Keywords: Bronchiectasis, exacerbations, gender, haemoptysis, mortality, Reiff score, sex

Differences in Nutritional Status and Inflammatory Biomarkers between Female and Male Patients with Bronchiectasis: A Large-Cohort Study

We hypothesized that systemic inflammatory and nutritional parameters may differ between male and female patients with non-CF bronchiectasis. In a large patient cohort from the Spanish Online Bronchiectasis Registry (RIBRON), clinical features, systemic inflammatory and nutritional parameters were analyzed in male and female patients with bronchiectasis. Lung function, disease severity using several scores, nutritional status, systemic inflammatory parameters, and multivariate regression analyses were performed to identify differences between male and female patients in the target variables. The number of female patients included in the registry was greater than male patients and they had a less severe disease as measured by all three indices of disease severity, a lower degree of airway obstruction, worse diffusion capacity and airway trapping, better nutritional parameters, and lower levels of inflammatory biomarkers. Multivariate regression analysis evidenced that strong relationships were found between female gender and the following variables: total numbers of leukocytes and neutrophils, hemoglobin, hematocrit, creatinine, and body mass index (BMI). Multivariate regression analyses evidenced that nutritional parameters and inflammatory biomarkers may be reliable indicators of gender-related differences in patients with non-CF bronchiectasis. These findings deserve further attention in follow-up investigations in which the potential predictive value of those biomarkers should be thoroughly explored.

Sex and Gender Differences in Lung Disease

Sex differences in the anatomy and physiology of the respiratory system have been widely reported. These intrinsic sex differences have also been shown to modulate the pathophysiology, incidence, morbidity, and mortality of several lung diseases across the life span. In this chapter, we describe the epidemiology of sex differences in respiratory diseases including neonatal lung disease (respiratory distress syndrome, bronchopulmonary dysplasia) and pediatric and adult disease (including asthma, cystic fibrosis, idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease, lung cancer, lymphangioleiomyomatosis, obstructive sleep apnea, pulmonary arterial hypertension, and respiratory viral infections such as respiratory syncytial virus, influenza, and SARS-CoV-2). We also discuss the current state of research on the mechanisms underlying the observed sex differences in lung disease susceptibility and severity and the importance of considering both sex and gender variables in research studies' design and analysis.

The Human Microbiome, an Emerging Key-Player in the Sex Gap in Respiratory Diseases

The sex gap is well-documented in respiratory diseases such as cystic fibrosis and chronic obstructive pulmonary disease. While the differences between males and females in prevalence, severity and prognosis are well-established, the pathophysiology of the sex difference has been poorly characterized to date. Over the past 10 years, metagenomics-based studies have revealed the presence of a resident microbiome in the respiratory tract and its central role in respiratory disease. The lung microbiome is associated with host immune response and health outcomes in both animal models and patient cohorts. The study of the lung microbiome is therefore an interesting new avenue to explore in order to understand the sex gap observed in respiratory diseases. Another important parameter to consider is the gut-lung axis, since the gut microbiome plays a crucial role in distant immune modulation in respiratory diseases, and an intestinal “microgenderome” has been reported: i.e., sexual dimorphism in the gut microbiome. The microgenderome provides new pathophysiological clues, as it defines the interactions between microbiome, sex hormones, immunity and disease susceptibility. As research on the microbiome is increasing in volume and scope, the objective of this review was to describe the state-of-the-art on the sex gap in respiratory medicine (acute pulmonary infection and chronic lung disease) in the light of the microbiome, including evidence of local (lung) or distant (gut) contributions to the pathophysiology of these diseases.

Bronchiectasis-Could Immunonutrition Have a Role to Play in Future Management?

Bronchiectasis is a chronic condition in which areas of the bronchial tubes become permanently widened predisposing the lungs to infection. Bronchiectasis is an age-associated disease with the highest prevalence in people older than 75 years. While the prevalence of bronchiectasis is higher in males, disease is more severe in females who have a poorer prognosis. The overall prevalence of the disease is thought to be rising. Its aetiology is multi-faceted, but a compromised immune system is now thought to play a central role in the pathology of this disease. Research has begun to study the role of malnutrition and certain nutrients-vitamin D and zinc-along with the role of the lung microbiome in relation to the management of bronchiectasis. Given this, the present mini review sets out to provide an overview of the state-of-the-art within the field, identify research gaps and pave the way for future developments and research investment within this field.

Pseudomonas aeruginosa in bronchiectasis: infection, inflammation, and therapies

Introduction: Bronchiectasis is a chronic endobronchial suppurative disease characterized by irreversibly dilated bronchi damaged by repeated polymicrobial infections and predominantly, neutrophilic airway inflammation. Some consider bronchiectasis a syndromic consequence of several different causes whilst others view it as an individual disease entity. In most patients, identifying an underlying cause remains challenging. The acquisition and colonization of affected airways by Pseudomonas aeruginosa represent a critical and adverse clinical consequence for its progression and management.Areas covered: In this review, we outline clinical and pre-clinical peer-reviewed research published in the last 5 years, focusing on the pathogenesis of bronchiectasis and the role of P. aeruginosa and its virulence in shaping host inflammatory and immune responses in the airway. We further detail its role in airway infection, the lung microbiome, and address therapeutic options in bronchiectasis.Expert opinion: P. aeruginosa represents a key pulmonary pathogen in bronchiectasis that causes acute and/or chronic airway infection. Eradication can prevent adverse clinical consequence and/or disease progression. Novel therapeutic strategies are emerging and include combination-based approaches. Addressing airway infection caused by P. aeruginosa in bronchiectasis is necessary to prevent airway damage, loss of lung function and exacerbations, all of which contribute to adverse clinical outcome.

The airway microbiome in COPD, bronchiectasis and bronchiectasis-COPD overlap

OBJECTIVE

To review the airway microbiome in chronic obstructive pulmonary disease (COPD), bronchiectasis and bronchiectasis-COPD overlap (BCO).

DATA SOURCE AND STUDY SELECTION

Relevant studies were selected from PubMed, Google scholar, EMBASE and Web of Science. All studies involving human microbiomes, published in the English language, and using the search terms "COPD", "Chronic Obstructive Pulmonary Disease", "Bronchiectasis", "BCO" or "Bronchiectasis and COPD overlap", AND "microbiome", "mycobiome" or "metagenomics" were included.

RESULTS

Despite variability in sampling methods and specimen types used, microbiome composition remains relatively comparable in COPD and bronchiectasis with prominence of Proteobacteria, Firmicutes and Bacteroidetes. Alterations to airway microbiomes occur in association to disease severity and/or exacerbations in COPD and bronchiectasis. Decreased alpha diversity and Haemophilus-predominant microbiomes are associated with poorer survival in COPD, while, in bronchiectasis, Pseudomonas-predominant microbiomes demonstrate high exacerbation frequency and greater symptom burden while Aspergillus-dominant mycobiome profiles associate with exacerbations. The role of the microbiome in BCO remains understudied.

CONCLUSION

Use of next-generation sequencing has revolutionised our detection and understanding of the airway microbiome in chronic respiratory diseases such as COPD and bronchiectasis. Targeted amplicon sequencing reveals important associations between the respiratory microbiome and disease outcome while metagenomics may elucidate functional pathways. How best to apply this information into patient care, monitoring and treatment, however, remains challenging and necessitates further study.

Repeatability of the 6-min walk test in non-cystic fibrosis bronchiectasis

Non-cystic fibrosis bronchiectasis (NCFB) is a chronic lung disease characterized by progressive and irreversible changes of the bronchial tree. The evaluation of exercise capacity is essential to manage this disease. This study aims to determine the within-subject repeatability of two Six Minute Walk Test (6MWT) in adults with NCFB. NCFB. This cross-sectional observational study included 66 NCFB subjects above 18 years-old (mean of 55 ± 17 years old, 68% women). 73% of the participants presented moderate to severe clinical condition classified by Bronchiectasis Severity Index. It showed that these participants walked 16.6 m less (95%CI 3.8 to 29.4; p < 0.01) in the second 6MWT when compared to the first test, with a within-subject coefficient variation of 9.4% (95%CI 7.2-11.2%) and an intra-test reliability with a high intraclass correlation coefficient of 0.88 (95%CI 0.80-0.93). Bland-Altman plot showed an agreement regarding test repeatability, besides presented a large limit of agreement (- 85 to 116 m). Respiratory rate and systolic blood pressure were significantly higher before starting the second test. In conclusion, 6MWT seems to be reproducible in NCFB subjects and vital sign verification should be attentively checked to assess if the patient is fully recovered to perform a second test, as well as the disease severity score. Other studies on this matter should be conducted with a larger number of participants to confirm the findings of the present study.

Sex Steroids Induce Membrane Stress Responses and Virulence Properties in Pseudomonas aeruginosa

Molecular mechanisms by which sex steroids interact with P. aeruginosa to modulate its virulence have yet to be reported. Our work provides the first characterization of a steroid-induced membrane stress mechanism promoting P. aeruginosa virulence, which includes the release of proinflammatory outer membrane vesicles, resulting in inflammation, host tissue damage, and reduced bacterial clearance. We further demonstrate that at nanomolar (physiological) concentrations, male and female sex steroids promote virulence in clinical strains of P. aeruginosa based on their dynamic membrane fluidic properties. This work provides, for the first-time, mechanistic insight to better understand and predict the P. aeruginosa related response to sex steroids and explain the interindividual patient variability observed in respiratory diseases such as cystic fibrosis that are complicated by gender differences and chronic P. aeruginosa infection.

Estrogen, a major female sex steroid hormone, has been shown to promote the selection of mucoid Pseudomonas aeruginosa in the airways of patients with chronic respiratory diseases, including cystic fibrosis. This results in long-term persistence, poorer clinical outcomes, and limited therapeutic options. In this study, we demonstrate that at physiological concentrations, sex steroids, including testosterone and estriol, induce membrane stress responses in P. aeruginosa. This is characterized by increased virulence and consequent inflammation and release of proinflammatory outer membrane vesicles promoting in vivo persistence of the bacteria. The steroid-induced P. aeruginosa response correlates with the molecular polarity of the hormones and membrane fluidic properties of the bacteria. This novel mechanism of interaction between sex steroids and P. aeruginosa explicates the reported increased disease severity observed in females with cystic fibrosis and provides evidence for the therapeutic potential of the modulation of sex steroids to achieve better clinical outcomes in patients with hormone-responsive strains.

Effect of Sex Differences on Computed Tomography Findings in Adults With Cystic Fibrosis: A Multicenter Study

BACKGROUND

The survival of women with cystic fibrosis (CF) is lower than that of men by approximately 5 years. While various factors have been put forward to account for this discrepancy, no specific reasons have been established. Our hypothesis was that anatomical-structural involvement is more pronounced in women with CF than in men and that this is reflected in thoracic HRCT findings.

MATERIAL AND METHODS

We performed a prospective multicentre study, in which adult patients were consecutively included over 18 months. Chest HRCT was performed, and findings were scored by 2 thoracic radiologists using the modified Bhalla system. We also studied respiratory function, applied the CFQR 14+ questionnaire, and collected clinical variables.

RESULTS

Of the 360 patients followed up in the participating units, 160 were eventually included. Mean age was 28 years, and 47.5% were women. The mean±SD global score on the modified Bhalla score was 13.7±3.8 in women and 15.2±3.8 in men (p=0.024). The highest scores were observed for sacculations, bronchial generations, and air trapping in women. Women had lower BMI, %FEV₁, %FVC, and %DLCO. Similarly, the results for the respiratory domain in CFQR 14+ were worse in women, who also had more annual exacerbations.

CONCLUSIONS

This is the first study to provide evidence of the implication of sex differences in HRCT findings in patients with CF. Women with CF present a more severe form of the disease that results in more frequent exacerbations, poorer functional and nutritional outcomes, deterioration of quality of life, and greater structural damage.

Early Age at Natural Menopause Is Related to Lower Post-Bronchodilator Lung Function. A Longitudinal Population-based Study

Rationale: Poor lung function, a significant predictor of mortality, has been observed in postmenopausal women compared with those still menstruating. Menopausal age is a risk factor for several adverse health outcomes, but little evidence exists on the impact of menopausal age on lung function impairments, especially regarding post-bronchodilator lung function measures.Objectives: To investigate the association between age at menopause and pre- and post-bronchodilator lung function outcomes.Methods: During the sixth-decade follow-up of the Tasmanian Longitudinal Health Study cohort (mean age, 53 yr), information was collected on most recent menstrual period and menopausal status. Lung function was measured at age 7 years and again at 53 years. Multiple linear regression was performed to determine the association between age at menopause and pre- and post-bronchodilator spirometry, controlling for early and adult life confounders.Results: Women reporting an early age at natural menopause (<45 yr) had lower post-bronchodilator forced expiratory volume in 1 second (-168 ml; 95% confidence interval, -273 to -63) and lower forced vital capacity (-186 ml; 95% confidence interval, -302 to -70) than postmenopausal women who experienced menopause at a later age (≥45 yr). No association was observed with forced expiratory volume in 1 second/forced vital capacity ratio. Adjustment for early-life confounders strengthened these associations.Conclusions: This study provides new evidence that early menopause is associated with reduced lung function that is suggestive of restriction, but not obstruction, even after adjustment for early-life confounders. Given the important link between poor lung function and mortality, clinicians should be aware of the risk of diminished lung function in postmenopausal women who experience menopause at an early age.

Hot topics and current controversies in non-cystic fibrosis bronchiectasis

Non-cystic fibrosis bronchiectasis (NCFB) is a neglected and orphan disease with poor advances through the 20th century. However, its prevalence is rising and with this come new challenges for physicians. Few guidelines are available to guide clinicians on how to diagnose and manage patients with NCFB. Many areas of debate persist, and there is lack of consensus about research priorities most needed to advance patient care and improve clinical outcomes. In this review, we highlight the current hot topics in NCFB and present updated evidence to inform the critical areas of controversy.

Non-cystic fibrosis bronchiectasis (NCFB) is a neglected and orphan disease with poor advances through the 20th century. Physicians should understand available data to provide evidence-based treatments to patients suffering from NCFB.http://bit.ly/2kBGVsx

The role of sex in particle-induced inflammation and injury

The use of engineered nanomaterials within various applications such as medicine, electronics, and cosmetics has been steadily increasing; therefore, the rate of occupational and environmental exposures has also increased. Inhalation is an important route of exposure to nanomaterials and has been shown to cause various respiratory diseases in animal models. Human lung disease frequently presents with a sex/gender-bias in prevalence or severity, but investigation of potential sex-differences in the adverse health outcomes associated with nanoparticle inhalation is greatly lacking. Only ~20% of basic research in the general sciences use both male and female animals and a substantial percentage of these do not address differences between sexes within their analyses. This has prevented researchers from fully understanding the impact of sex-based variables on health and disease, particularly the pathologies resulting from the inhalation of particles. The mechanisms responsible for sex-differences in respiratory disease remain unclear, but could be related to a number of variables including sex-differences in hormone signaling, lung physiology, or respiratory immune function. By incorporating sex-based analysis into respiratory nanotoxicology and utilizing human data from other relevant particles (e.g., asbestos, silica, particulate matter), we can improve our understanding of sex as a biological variable in nanoparticle exposures. This article is categorized under: Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials.

Association Between Solid Cooking Fuels and Respiratory Disease Across Socio-Demographic Groups in India

BACKGROUND

The use of solid fuels in household cooking contributes to indoor air pollution and is the cause of more than 4 million deaths around the world annually. Solid fuel use varies with the level of development and ranges from 0% in high-income countries to more than 80% in low- and middle-income countries. Three billion people (more than 40% of the global population) are still dependent on solid fuels like firewood, dung cakes, coal, wood and agricultural residues in these countries.

OBJECTIVES

The present study aims to analyze the association of certain respiratory diseases (tuberculosis (TB), acute upper respiratory infections (AURI), chronic obstructive pulmonary diseases (COPD), and bronchial asthma) with the use of solid fuels for cooking across sociodemographic groups in India.

METHODS

The 71st round of the National Sample Survey, conducted in 2014, was used. In total, 54,985 inpatients who received medical treatment from any medical institution during the last 365 days preceding the survey and who reported various diseases, such as infections, cancers, blood diseases, cardiovascular diseases, and respiratory diseases were included in the analysis. Of these inpatients, 2513 participants who reported TB, AURI, COPD and bronchial asthma were considered the dependent variables in the study. The main variable was exposure to different types of fuels used as a primary source of energy for cooking. Multinomial logistic regression was used to explain associations.

RESULTS

The results reveal a significant association between solid fuel use and respiratory diseases in India. Overall, more than 60% of the population uses firewood and cow dung as their primary source of energy for cooking and are at a higher risk of TB, COPD and bronchial asthma. In rural areas there is a high dependence on solid fuels (80.5%) and a higher risk of respiratory diseases compared to those residing in urban areas where people are less dependent on solid fuels (22%). Among different socio-demographic groups, the dependence on solid fuels is highest among Scheduled Tribes (87.42%), followed by Scheduled Castes (74.78%) and Other Backward Classes (OBCs) (a term used by the Indian government to categorize castes that face social or educational challenges) (64.47%). Scheduled Tribes have the highest risk of TB, followed by Scheduled Castes and OBCs, respectively.

CONCLUSIONS

Exposure to solid fuels for cooking increases the potential risk of TB, COPD and bronchial asthma. Access to clean and efficient fuels for cooking is essential to reduce the burden of respiratory disease. Measures are needed to increase the availability of clean fuels for households, especially among socially disadvantaged and marginalized groups, to reduce the burden of respiratory diseases in India.

COMPETING INTERESTS

The authors declare no competing financial interests.

Sex differences in the inflammatory immune response to multi-walled carbon nanotubes and crystalline silica

Background: Respiratory disease is a leading cause of death and disability worldwide. These diseases frequently present with a sex bias in occurrence and severity, yet the mechanisms responsible for these sex biases is a critically understudied area of basic research. Methods: Male and female C57BL/6 mice were exposed to multi-walled carbon nanotubes (MWCNTs) or crystalline silica (cSiO2) via oropharyngeal aspiration. Acute assessments were conducted 24 h and 7 days after a single exposure. In chronic experiments, mice were exposed to respective particles once per week for 4 weeks and sacrificed 8 weeks after the last exposure. Lung lavage fluid (LLF) was assessed for markers of injury and inflammation. Immune cell populations were analyzed by flow cytometry and histopathology assessment was performed on lung tissue from chronically exposed mice. Results: Female mice exposed to a single dose of MWCNTs generated a greater eosinophilic response than males 24 h and 7 days post-exposure. Eosinophilia was accompanied by elevated type 2 cytokine production in LLF. The exaggerated acute response in females was consistent with lung pathology observed in the chronic model: females had greater alveolitis and epithelial cell hyperplasia compared to males. There were no sex differences 24 h after cSiO2 exposure, but by 7-day post-exposure female mice had greater airspace neutrophilia and inflammatory cytokine levels compared to males. However, following repeated exposure to cSiO2, male mice had worse alveolitis and greater dendritic cell presence within the lungs. Conclusions: Female mice are more susceptible to acute and chronic MWCNT-induced inflammation, but male mice are more susceptible to chronic cSiO2-induced lung pathology.