Impulse Oscillometry in Adults with Bronchiectasis

Associations of personal urinary volatile organic compounds and lung function in children

BACKGROUND

We investigated the correlation between urine VOC metabolites and airway function in children exposed to anthropogenic volatile organic compounds (VOCs), notable pollutants impacting respiratory health.

METHODS

Out of 157 respondents, 141 completed skin prick tests, spirometry, IOS, and provided urine samples following the International Study of Asthma and Allergies in Childhood (ISAAC)-related questions. Allergic sensitization was assessed through skin prick tests, and airway functions were evaluated using spirometry and impulse oscillometry (IOS). Forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) was recorded and FEV1/FVC ratio was calculated. Airway mechanics parameters including respiratory resistance at 5 Hz (Rrs5) mean respiratory resistance between 5 Hz and 20 Hz (Rrs5-20), were also recorded. Urine concentrations of metabolites of benzene, ethylbenzene, toluene, xylene, styrene, formaldehyde, carbon-disulfide were analyzed by gas chromatography/tandem mass spectroscopy.

RESULTS

The median age at study participation was 7.1 (SD 0.3) years. Muconic acid (benzene metabolites) and o-methyl-hippuric acid (xylene metabolites) above medians were associated with a significant increase in Rrs5 (muconic acid: aβ = 0.150, p = .002; o-methyl-hippuric acid: aβ = 0.143, p = .023) and a decrease in FEV1/FVC (o-methyl-hippuric acid: aβ = 0.054, p = .028) compared to those below median. No associations were observed for Rrs5-20 and FEV1 between the groups categorized as above and below the median (all parameter p values > .05).

CONCLUSIONS

Elevated levels of benzene and xylene metabolites were associated with a significant increase in Rrs5 and a decrease in FEV1/FVC, related to increased resistance and restrictive lung conditions compared to individuals with concentrations below the median.

Biomarkers in bronchiectasis

Bronchiectasis is a heterogeneous disease with multiple aetiologies and diverse clinical features. There is a general consensus that optimal treatment requires precision medicine approaches focused on specific treatable disease characteristics, known as treatable traits. Identifying subtypes of conditions with distinct underlying biology (endotypes) depends on the identification of biomarkers that are associated with disease features, prognosis or treatment response and which can be applied in clinical practice. Bronchiectasis is a disease characterised by inflammation, infection, structural lung damage and impaired mucociliary clearance. Increasingly there are available methods to measure each of these components of the disease, revealing heterogeneous inflammatory profiles, microbiota, radiology and mucus and epithelial biology in patients with bronchiectasis. Using emerging biomarkers and omics technologies to guide treatment in bronchiectasis is a promising field of research. Here we review the most recent data on biomarkers in bronchiectasis.

Nasal oxidative stress mediating the effects of colder temperature exposure on pediatric asthma symptoms

BACKGROUND

Colder temperature exposure is a known trigger for pediatric asthma exacerbation. The induction of oxidative stress is a known pathophysiologic pathway for asthma exacerbation. However, the role of oxidative stress in linking colder temperature exposure and worsened pediatric asthma symptoms is poorly understood.

METHODS

In a panel study involving 43 children with asthma, aged 5-13 years old, each child was visited 4 times with a 2-week interval. At each visit, nasal fluid, urine, and saliva samples were obtained and measured for biomarkers of oxidative stress in the nasal cavity (nasal malondialdehyde [MDA]), the circulatory system (urinary MDA), and the oral cavity (salivary MDA). Childhood Asthma-Control Test (CACT) was used to assess asthma symptoms.

RESULTS

When ambient daily-average temperature ranged from 7 to 18 °C, a 2 °C decrement in personal temperature exposures were significantly associated with higher nasal MDA and urinary MDA concentrations by 47-77% and 6-14%, respectively. We estimated that, of the decrease in child-reported CACT scores (indicating worsened asthma symptoms and asthma control) associated with colder temperature exposure, 14-57% were mediated by nasal MDA.

CONCLUSION

These results suggest a plausible pathway that colder temperature exposure worsens pediatric asthma symptoms partly via inducing nasal oxidative stress.

IMPACT

The role of oxidative stress in linking colder temperature exposure and worsened asthma symptoms is still poorly understood. Lower temperature exposure in a colder season was associated with higher nasal and systemic oxidative stress in children with asthma. Nasal MDA, a biomarker of nasal oxidative stress, mediated the associations between colder temperature exposures and pediatric asthma symptoms. The results firstly suggest a plausible pathway that colder temperature exposure worsens pediatric asthma symptoms partly via inducing oxidative stress in the nasal cavity.

Research advances and clinical management of bronchiectasis: Chinese perspective

Bronchiectasis is a debilitating chronic suppurative airway disease that confers a substantial burden globally. Despite the notable prevalence, research on bronchiectasis in mainland China remains in its infancy. Nevertheless, there has been a significant leap in the quantity and quality of research, which has contributed to the ever-improving clinical practice. A nationwide collaborative platform has been established to foster multicentre studies, which will help increase the level of evidence further. Here, we summarise the status quo of clinical management and consider the research priorities for bronchiectasis that have been published previously. We also highlight the efforts of the Chinese medical communities to outline the core tasks that need to be addressed within the next decade.

The clinical impact of self-reported symptoms of chronic rhinosinusitis in people with bronchiectasis

BACKGROUND

Chronic rhinosinusitis affects 62% of adults with bronchiectasis and is linked to greater bronchiectasis severity. However, the impact of symptoms of chronic rhinosinusitis on disease-specific and cough-related quality of life is unknown.

METHODS

In this cross-sectional study, adults with stable bronchiectasis and chronic rhinosinusitis symptoms completed the sinonasal outcome test-22 (SNOT-22), quality of life-bronchiectasis questionnaire, and Leicester cough questionnaire. Bronchiectasis severity was assessed using the bronchiectasis severity index (BSI) and chest high-resolution computed tomography (HRCT).

RESULTS

Sixty participants with bronchiectasis (mean [SD] forced expiratory volume in 1 s of 73.2 [25.5] %predicted) were included. Greater severity of chronic rhinosinusitis symptoms (based on SNOT-22) was moderately associated with impaired cough-related quality of life (according to the Leicester cough questionnaire; all r > -.60) and impaired bronchiectasis-specific quality of life (based on the quality of life-bronchiectasis questionnaire), with impaired physical function (r = -.518), less vitality (r = -.631), reduced social function (r = -.546), greater treatment burden (r = -.411), and increased severity of respiratory symptoms (r = -.534). Chronic rhinosinusitis symptoms were unrelated to disease severity according to the BSI (r = .135) and HRCT scoring (all r < .200). The severity of chronic rhinosinusitis symptoms was not affected by sputum color (p = .417) or the presence of Pseudomonas aeruginosa colonization (p = .73).

CONCLUSIONS

In adults with bronchiectasis, chronic rhinosinusitis has a consistent and negative impact on both cough-related and bronchiectasis-specific quality of life.

Impact of bronchial wall thickness on airflow obstruction in bronchiectasis

The association between airflow obstruction and bronchial dilation has been researched in bronchiectasis. However, the impact of bronchial wall thickening on airflow obstruction has not been thoroughly investigated. This study assessed the underlying mechanism of airflow obstruction in bronchiectasis due to abnormal bronchial wall thickening using oscillometry. A total of 98 patients with bronchiectasis were retrospectively reviewed. At the time of diagnosis, spirometric and oscillometric parameters, high-resolution computed tomography scores, and clinical characteristics were collected. The bronchial diameter, bronchial wall thickness, and extent of emphysema were evaluated semi-quantitatively. Correlations between patient data and characteristics were analyzed. Thirty-three patients with airflow obstruction showed higher respiratory resistance, more negative respiratory reactance (Xrs) at 5 Hz (X5), and higher bronchial wall thickness score than those without airflow obstruction. The bronchial wall thickness score negatively affected forced expiration volume in 1 s /forced vital capacity and X5. Abnormal bronchial wall thickening might make Xrs more negative and progress airflow obstruction in bronchiectasis.

Effects of Controlled Voluntary Increase in the Ventilatory Demand on Respiratory System Resistance in Healthy and Non-Cystic Fibrosis Bronchiectasis Subjects: A Cross-Sectional Study

INTRODUCTION

Bronchiectasis patients may present a reduced functional capacity due to an increase in the ventilatory demand during exercise.

OBJECTIVE

To evaluate the effects of controlled voluntary hyperinflation and increased respiratory rate on the mechanics of the respiratory system, simulating what happens during exercise, in bronchiectasis and healthy subjects.

METHODS

Bronchiectasis (n=30) and healthy (n=16) subjects were evaluated by impulse oscillometry (IOS) during a baseline condition, and in controlled conditions with baseline (b) tidal volume (V) and hyperinflation (H), with respiratory rates at 30(R30) and 40(R40) bpm, in a random order. The mixed effects and a significance level at 0.05 were used for comparisons.

RESULTS

Resistance at 5Hz (R5), and at minus 20Hz (R5-R20), in kPa/L/s, were higher in subjects with bronchiectasis in all experimental conditions (p<0.05). For the bronchiectasis group, R5 and R5-20 increased with R increase at V (VRb versus VR30 and VR40; VR30 versus VR40; R5, R20 and R5-20 increased with R increase at H (HRb versus HR40; HR30 versus HR40). For the same R, there was a decrease with H compared to V (HRb versus VR30 and VR40; and HR30 versus VR30 and VR40). For the healthy group, only R20 showed differences (HR30 versus HR40; HR40 versus VR40).

CONCLUSION

The tachypnea increases the resistance and reactance of the respiratory system in bronchiectasis patients, and the voluntary hyperinflation caused attenuates this increase. These results can guide the development of strategies to reduce the limitation of physical activity in patients with bronchiectasis.

Reference values of respiratory impedance with impulse oscillometry in healthy Chinese adults

Background

Impulse oscillometry (IO) is a non-invasive pulmonary function test for measuring respiratory impedance. Available reference equations of IO indices for adults are limited. The aim of this study was to develop reference equations of IO indices for Chinese adults.

Methods

In a multicentral, cross-sessional study of IO in Chinese adults, IO data from healthy subjects were collected from 19 general hospitals across China between 2016 and 2018. Oscillometry measurements were conducted in accordance with recommendations of the European Respiratory Society (ERS). Multiple linear regression was performed to develop sex-specific reference equations of IO indices.

Results

IO measurements were performed in 1,318 subjects, of which 567 subjects were defined as healthy individuals with acceptable IO data and were included in the final analysis. Reference equations and limits of normal [lower limit of normal (LLN)/upper limit of normal (ULN)] of IO indices were developed separately for males and females. Height but not age was shown to be the most influential contributor to IO indices. The reference equations currently used in lung function laboratories predicted higher R5 and X5. Normal ranges of R5 and X5 recommended by the equipment manufacturer were clearly different from the ULN/LLN derived from the reference equations.

Conclusions

Reference equations of IO indices for Chinese adults from a wide region were provided in this study. It is necessary to update new IO reference equations and adopt ULN/LLN as normal ranges of IO indices.

Trial Registration

This study was registered at www.clinicaltrials.gov as part of a larger study NCT03467880.

Personal Exposure to PM2.5 Oxidative Potential in Association with Pulmonary Pathophysiologic Outcomes in Children with Asthma

Fine particulate matter (PM_2.5) with a higher oxidative potential has been thought to be more detrimental to pulmonary health. We aim to investigate the associations between personal exposure to PM_2.5 oxidative potential and pulmonary outcomes in asthmatic children. We measured each of the 43 asthmatic children 4 times for airway mechanics, lung function, airway inflammation, and asthma symptom scores. Coupling measured indoor and outdoor concentrations of PM_2.5 mass, constituents, and oxidative potential with individual time-activity data, we calculated 24 h average personal exposures 0-3 days prior to a health outcome measurement. We found that increases in daily personal exposure to PM_2.5 oxidative potential were significantly associated with increased small, large, and total airway resistance, increased airway impedance, decreased lung function, and worsened scores of individual asthma symptoms and the total symptom score. Among the PM_2.5 constituents, organic matters largely of indoor origin contributed the greatest to PM_2.5 oxidative potential. Given that the variability in PM_2.5 oxidative potential was a stronger driver than PM_2.5 mass for the variability in the respiratory health outcomes, it is suggested to reduce PM_2.5 oxidative potential, particularly by reducing the organic matter constituent of indoor PM_2.5, as a targeted source control strategy in asthma management.

Comparative evaluation of expiratory airflow limitation between patients with COPD and BE using IOS

Impulse oscillometry (IOS) allows evaluation of the compartmentalized resistance and reactance of the respiratory system, distinguishing central and peripheral obstruction. The IOS measurements are getting attention in the diagnosis and differentiation of chronic respiratory diseases. However, no data are available in the literature to differentiate between COPD and BE using IOS parameters. We aimed to evaluate the feasibility of IOS in the diagnosis of bronchiectasis non-cystic fibrosis (BE) in comparison to COPD. Whole breath, inspiration, expiration, and inspiratory-expiratory difference (Δ) were evaluated based on the IOS parameters: total resistance (R5), central airway resistance (R20), peripheral airway resistance (R5-R20), reactance (X5), reactance area (AX), and resonance frequency (Fres). Fifty-nine subjects (21 Healthy, 19 BE, and 19 COPD) participated in this study. It was observed a significant difference in the comparison of healthy and pulmonary disease groups (BE and COPD) for total breathing (R5-R20, X5, AX, and Fres), inspiratory phase (R5 and R5-R5), and expiratory phase (R5-R20 and X5). The comparison between BE and COPD groups showed significant difference in the expiratory phase for resistance at 5 and 20 Hz and, ΔR5 and ΔR20. The IOS evidenced an increase of R5, R20 and R5-R20 in patients with BE and COPD when compared to healthy subjects. Expiratory measures of IOS revealed increased airway resistance in COPD compared to BE patients who had similar FEV1 measured by spirometry, however, further studies are needed to confirm these differences.

Evaluation of disease severity in bronchiectasis using impulse oscillometry

Although the diagnostic value of impulse oscillometry (IOS) in bronchiectasis for the differential diagnosis of healthy subjects has been researched, the usefulness of each IOS parameter for predicting disease severity in bronchiectasis has not been thoroughly investigated. In addition, the usefulness of IOS in patients with nontuberculous mycobacteria (NTM) infection has not been reported. This study aimed to determine the predictive significance of respiratory impedance and detect the other most significant IOS parameters for predicting disease severity in bronchiectasis patients and to validate the usefulness of IOS in patients with NTM infection.

A total of 206 patients with bronchiectasis who attended clinics at the National Hospital Organization Osaka Toneyama Medical Center were included. Chest high-resolution computed tomography, spirometry and IOS were performed. Hospital admissions, mortality and disease severity indices for bronchiectasis (Bronchiectasis Severity Index (BSI), FACED, and E-FACED scores) were calculated to assess disease severity. The patients were divided into subgroups with and without NTM infection, and subgroup analyses were performed.

Respiratory reactance, especially resonant frequency (f_res), correlated with both BSI and FACED score better than respiratory resistance. Inspiratory but not expiratory impedance was strongly correlated with BSI, FACED and E-FACED scores. Inspiratory f_res was the most useful predictor, increasing as the disease became more severe. The usefulness of IOS was almost equivalent in patients both with and without NTM infection.

Inspiratory reactance measured by IOS is useful for estimating disease severity in bronchiectasis. Inspiratory f_res best predicts disease severity in bronchiectasis patients both with and without NTM infection.

Inspiratory reactance measured by impulse oscillometry may be useful for estimating disease severity of bronchiectasis. Inspiratory f_res can be used to evaluate severity in the disease both with and without NTM infection.https://bit.ly/3fvG0Rn

Application of Impulse Oscillometry in Adult Asthmatic Patients With Preserved Lung Function

PURPOSE

It is difficult to assess airway obstruction using spirometry in adult asthmatic patients with preserved lung function. Impulse oscillometry (IOS) can detect not only airway resistance but also reactance. Therefore, IOS may be useful in assessing pulmonary function in such patients. We investigated the applicability of IOS for asthma patients with preserved lung function.

METHODS

Between 2015 and 2018, 1,248 adult asthmatic patients suspected of having asthma who visited the Allergy and Asthma Center of Severance Hospital underwent both spirometry and IOS. Consequently, 784 patients had asthma, 111 had chronic obstructive lung disease (COPD) or asthma-COPD overlap, and 7 had parenchymal lung disease. The remaining 346 patients had chronic cough without underlying lung or airway disease. Among the 784 asthmatic patients, 191 with decreased lung function (predicted forced expiratory volume in 1 second [FEV1] < 80%) were excluded. Propensity score matching was performed to adjust baseline characteristics between 346 non-asthmatic and 593 asthmatic patients with preserved lung function. Subsequently, we compared the spirometry and IOS parameters between the 329 asthmatic and 329 non-asthmatic patients.

RESULTS

Multiple logistic regression analysis showed that the area of reactance (AX) was associated with asthma with preserved lung function. In receiver operating characteristic (ROC) curve analysis, the area under the curve (AUC) of AX (AUC = 0.6823) for asthma was not significantly different from that of FEV1 (AUC = 0.6758). However, the AUC of a combination of AX and FEV1 (AUC = 0.7437) for asthma was significantly higher than that of FEV1 alone. The cutoff value of AX was 0.51 kPa/L in univariate ROC analysis.

CONCLUSIONS

AX is associated with adult asthma with preserved lung function. Performing spirometry together with IOS is more beneficial than performing spirometry alone for diagnosing asthma in adult patients with preserved lung function.

Measuring airway clearance outcomes in bronchiectasis: a review

While airway clearance techniques (ACTs) are recommended for individuals with bronchiectasis, many trials have demonstrated inconsistent benefits or failed to reach their primary outcome. This review determined the most common clinical and patient-reported outcome measures used to evaluate the efficacy of ACTs in bronchiectasis. A literature search of five databases using relevant keywords and filtering for studies published in English, up until the end of August 2019, was completed. Studies included randomised controlled trials, using crossover or any other trial design, and abstracts. Studies were included where the control was placebo, no intervention, standard care, usual care or an active comparator. Adults with bronchiectasis not related to cystic fibrosis were included. Extracted data comprised study authors, design, duration, intervention, outcome measures and results. The search identified 27 published studies and one abstract. The most common clinical outcome measures were sputum volume (n=23), lung function (n=17) and pulse oximetry (n=9). The most common patient-reported outcomes were health-related quality of life (measured with St George's Respiratory Questionnaire, n=4), cough-related quality of life (measured with Leicester Cough Questionnaire, n=4) and dyspnoea (measured with Borg/modified Borg scale, n=8). Sputum volume, lung function, dyspnoea and health- and cough-related quality of life appear to be the most common clinical and patient-reported measures of airway clearance treatment efficacy.

Effects of Controlled Voluntary Increase in the Ventilatory Demand on Respiratory System Resistance in Healthy and Non-Cystic Fibrosis Bronchiectasis Subjects: A Cross-Sectional Study

INTRODUCTION

Bronchiectasis patients may present a reduced functional capacity due to an increase in the ventilatory demand during exercise.

OBJECTIVE

To evaluate the effects of controlled voluntary hyperinflation and increased respiratory rate on the mechanics of the respiratory system, simulating what happens during exercise, in bronchiectasis and healthy subjects.

METHODS

Bronchiectasis (n=30) and healthy (n=16) subjects were evaluated by impulse oscillometry (IOS) during a baseline condition, and in controlled conditions with baseline (b) tidal volume (V) and hyperinflation (H), with respiratory rates at 30(R30) and 40(R40) bpm, in a random order. The mixed effects and a significance level at 0.05 were used for comparisons.

RESULTS

Resistance at 5Hz (R5), and at minus 20Hz (R5-R20), in kPa/L/s, were higher in subjects with bronchiectasis in all experimental conditions (p<0.05). For the bronchiectasis group, R5 and R5-20 increased with R increase at V (VRb versus VR30 and VR40; VR30 versus VR40; R5, R20 and R5-20 increased with R increase at H (HRb versus HR40; HR30 versus HR40). For the same R, there was a decrease with H compared to V (HRb versus VR30 and VR40; and HR30 versus VR30 and VR40). For the healthy group, only R20 showed differences (HR30 versus HR40; HR40 versus VR40).

CONCLUSION

The tachypnea increases the resistance and reactance of the respiratory system in bronchiectasis patients, and the voluntary hyperinflation caused attenuates this increase. These results can guide the development of strategies to reduce the limitation of physical activity in patients with bronchiectasis.

Associations of personal exposure to air pollutants with airway mechanics in children with asthma

BACKGROUND

The importance of airway mechanics has been increasingly recognized in pediatric asthma. However, no studies have examined responses of airway mechanics to air pollution exposure in asthmatic children.

METHODS

In this panel study involving indoor air filtration manipulation that created a large gradient of personal exposure to PM_2.5, the airway mechanics and lung function of 43 asthmatic children 5-13 years old in a suburb of Shanghai were measured four times within 3 consecutive months. Concentrations of indoor and outdoor PM_2.5 and ozone were coupled with individual time-activity data to calculate personal exposures. Linear mixed effects models were used to examine the relationships of personal exposure with indicators of airway mechanics and lung function, respectively.

RESULTS

An interquartile range (IQR) increase in 24-hour average PM_2.5 personal exposure (30.3 µg/m³) in the prior day was associated with significant increases in small airway resistance (R₅-R₂₀) of 15.8%, total airway resistance (R₅) of 6.3%, and airway inflammation (FeNO) of 9.6%. These associations were stronger in children with lower blood eosinophil counts (<450/µL). No significant associations were found between personal PM_2.5 exposure and lung function. Low-level ozone exposure (daily maximum 8-hour exposure range 1.1-56.4 ppb) was not significantly associated with any of the outcomes.

CONCLUSION

Changes in personal PM_2.5 exposure, partly enhanced by air filtration, were associated with significant changes in airway resistance and inflammation in children with asthma. These findings suggest the importance of reducing PM_2.5 exposure, via personal air quality management, in improving airflow limitation in the airways, especially the small airways.

Small and large airways' reactions to inhaled capsaicin in patients with chronic idiopathic cough, or asthma and in healthy control subjects

Aims: Cough is a common medical problem, and when it persists for more than 8 weeks it is arbitrarily defined as chronic. While spirometry assesses the large airways, impulse oscillometry system (IOS) measures peripheral airway function. The present study investigated whether provocation with inhaled capsaicin affects the large and small airways in patients with chronic idiopathic cough (CIC) or asthma and in healthy controls. Materials and methods: Twenty-one patients with CIC, 18 patients with asthma, and 22 healthy controls were subjected to a provocation with capsaicin, and lung function was assessed by IOS and spirometry. Results: At baseline, before the capsaicin provocation, the CIC group had significantly increased airway resistance compared to the controls. After capsaicin provocation, the CIC group exhibited a significant increase in total airway resistance. The asthma group showed a small but significant reduction in spirometry, increased airway resistance, and reactance after capsaicin provocation. Capsaicin inhalation affected neither the spirometry nor the IOS of the healthy controls. Conclusions: The present study demonstrates that inhaled capsaicin induces changes in lung function, both in patients with CIC and in patients with asthma, when IOS, which measures changes also in the peripheral airways, is used. IOS appears to be a more sensitive tool than spirometry for the detection of airway impairment in airway provocation studies. In patients with CIC, higher peripheral resistance at baseline may have clinical significance.

Impedance Oscillometry: Emerging Role in the Management of Chronic Respiratory Disease

PURPOSE OF REVIEW

Chronic respiratory diseases affecting adults and children are widely prevalent, so lung function testing is imperative for diagnosis and management. Spirometry is the traditional standard measure of lung function; however, certain groups of patients are unable to provide accurate and reproducible exhalation maneuvers. Consequently, the impedance oscillometry system (IOS) has been developed as an effort, independent technique to assess airway function in children and the elderly. To better understand this emerging modality, the following review will compare IOS with spirometry, examine the function of the device, provide interpretation strategies, and discuss the evidence supporting its use in adults and children with chronic lung disease.

RECENT FINDINGS

In a population of symptomatic adults with suspected COPD, impedance oscillometry resistance measurements correlate with FEV₁ and lung resistance increases with the severity of airflow limitation. In patients with asthma, IOS is a sensitive measure of airway hyperresponsiveness and bronchodilator response. Impedance oscillometry is evolving as an alternative measure to assess lung function pediatric and adult populations.

Latin America validation of FACED score in patients with bronchiectasis: an analysis of six cohorts

BACKGROUND

The FACED score is an easy-to-use multidimensional grading system that has demonstrated an excellent prognostic value for mortality in patients with bronchiectasis. A Spanish group developed the score but no multicenter international validation has yet been published.

METHODS

Retrospective and multicenter study conducted in six historical cohorts of patients from Latin America including 651 patients with bronchiectasis. Clinical, microbiological, functional, and radiological variables were collected, following the same criteria used in the original FACED score study. The vital status of all patients was determined in the fifth year of follow-up. The area under ROC curve (AUC-ROC) was used to calculate the predictive power of the FACED score for all-cause and respiratory deaths and both number and severity of exacerbations. The discriminatory power to divide patients into three groups of increasing severity was also analyzed.

RESULTS

Mean (SD) age of 48.2 (16), 32.9% of males. The mean FACED score was 2.35 (1.68). During the follow up, 95 patients (14.6%) died (66% from respiratory causes). The AUC ROC to predict all-cause and respiratory mortality were 0.81 (95% CI: 0.77 to 0.85) 0.84 (95% CI: 0.80 to 0.88) respectively, and 0.82 (95% CI: 078-0.87) for at least one hospitalization per year. The division into three score groups separated bronchiectasis into distinct mortality groups (mild: 3.7%; moderate: 20.7% and severe: 48.5% mortality; p < 0.001).

CONCLUSIONS

The FACED score was confirmed as an excellent predictor of all-cause and respiratory mortality and severe exacerbations, as well as having excellent discriminative capacity for different degrees of severity in various bronchiectasis populations.

Multidimensional severity assessment in bronchiectasis: an analysis of seven European cohorts

INTRODUCTION

Bronchiectasis is a multidimensional disease associated with substantial morbidity and mortality. Two disease-specific clinical prediction tools have been developed, the Bronchiectasis Severity Index (BSI) and the FACED score, both of which stratify patients into severity risk categories to predict the probability of mortality.

METHODS

We aimed to compare the predictive utility of BSI and FACED in assessing clinically relevant disease outcomes across seven European cohorts independent of their original validation studies.

RESULTS

The combined cohorts totalled 1612. Pooled analysis showed that both scores had a good discriminatory predictive value for mortality (pooled area under the curve (AUC) 0.76, 95% CI 0.74 to 0.78 for both scores) with the BSI demonstrating a higher sensitivity (65% vs 28%) but lower specificity (70% vs 93%) compared with the FACED score. Calibration analysis suggested that the BSI performed consistently well across all cohorts, while FACED consistently overestimated mortality in 'severe' patients (pooled OR 0.33 (0.23 to 0.48), p<0.0001). The BSI accurately predicted hospitalisations (pooled AUC 0.82, 95% CI 0.78 to 0.84), exacerbations, quality of life (QoL) and respiratory symptoms across all risk categories. FACED had poor discrimination for hospital admissions (pooled AUC 0.65, 95% CI 0.63 to 0.67) with low sensitivity at 16% and did not consistently predict future risk of exacerbations, QoL or respiratory symptoms. No association was observed with FACED and 6 min walk distance (6MWD) or lung function decline.

CONCLUSION

The BSI accurately predicts mortality, hospital admissions, exacerbations, QoL, respiratory symptoms, 6MWD and lung function decline in bronchiectasis, providing a clinically relevant evaluation of disease severity.

Maximal mid-expiratory flow is a surrogate marker of lung clearance index for assessment of adults with bronchiectasis

Little is known about the comparative diagnostic value of lung clearance index (LCI) and maximal mid-expiratory flow (MMEF) in bronchiectasis. We compared the diagnostic performance, correlation and concordance with clinical variables, and changes of LCI and MMEF% predicted during bronchiectasis exacerbations (BEs). Patients with stable bronchiectasis underwent history inquiry, chest high-resolution computed tomography (HRCT), multiple-breath nitrogen wash-out test, spirometry and sputum culture. Patients who experienced BEs underwent these measurements during onset of BEs and 1 week following antibiotics therapy. Sensitivity analyses were performed in mild, moderate and severe bronchiectasis. We recruited 110 bronchiectasis patients between March 2014 and September 2015. LCI demonstrated similar diagnostic value with MMEF% predicted in discriminating moderate-to-severe from mild bronchiectasis. LCI negatively correlated with MMEF% predicted. Both parameters had similar concordance in reflecting clinical characteristics of bronchiectasis and correlated significantly with forced expiratory flow in one second, age, HRCT score, Pseudomonas aeruginosa colonization, cystic bronchiectasis, ventilation heterogeneity and bilateral bronchiectasis. In exacerbation cohort (n = 22), changes in LCI and MMEF% predicted were equally minimal during BEs and following antibiotics therapy. In sensitivity analyses, both parameters had similar diagnostic value and correlation with clinical variables. MMEF% predicted is a surrogate of LCI for assessing bronchiectasis severity.

Bronchodilator response in adults with bronchiectasis: correlation with clinical parameters and prognostic implications

BACKGROUND

Bronchial dilation testing is an important tool to assess airway reversibility in adults with bronchiectasis. This study aims to investigate the association of bronchodilator response (BDR) and clinical parameters in bronchiectasis, and the utility of BDR to indicate lung function decline and risks of bronchiectasis exacerbations (BEs).

METHODS

We recruited 129 patients with clinically stable bronchiectasis. Baseline measurements included assessment of sputum inflammation and matrix metalloproteinase-8 and -9, sputum bacterial culture, spirometry, bronchial dilation test (for baseline FEV1 less than 80% predicted only) and chest high-resolution computed tomography (HRCT). Bronchiectasis patients were followed-up for 1 year to determine the incidence of BEs and lung function trajectories. Significant BDR was defined as FEV1 improvement from pre-dose value by at least 200 mL and 12%. Clinical trial registry No.: NCT01761214; URL: www.clinicaltrials.gov.

RESULTS

BDR was negatively correlated with baseline FEV1 percentage predicted, but not blood or sputum eosinophil count. Significant BDR was not associated with greater proportion of never-smokers, poorer past history, greater HRCT scores, poorer diffusing capacity or increased sputum matrix metalloproteinases (all P>0.05). There was a trend towards higher bronchiectasis severity index (BSI) and greater proportion of patients with Pseudomonas aeruginosa isolation or infection. Significant BDR at baseline was linked to poorer spirometry, but not more rapid lung function decline, throughout follow-up. Patients with significant BDR demonstrated non-significantly lower risks of experiencing the first BEs than those without (P=0.09 for log-rank test).

CONCLUSIONS

Significant BDR is associated with poorer lung function compared with non-significant BDR. Whether BDR predicts future risks of BEs needs to be tested in a larger cohort.

Impacts of Co-Existing Chronic Rhinosinusitis on Disease Severity and Risks of Exacerbations in Chinese Adults with Bronchiectasis

BACKGROUND

Mounting evidence supports the notion of "one airway, one disease."

OBJECTIVE

To determine whether chronic rhinosinusitis (CRS) poses adverse impacts on Chinese adults with bronchiectasis.

METHODS

We enrolled 148 consecutive adults with clinically stable bronchiectasis. CRS diagnosed based on the 2012 EP3OS criteria. We systematically evaluated the bronchiectasis etiology, radiology, lung function, sputum bacteriology, airway inflammatory biomarkers, Bronchiectasis Severity Index, cough sensitivity and healthcare resource utilization. All patients were prospectively followed-up for 1 year to examine the frequency of bronchiectasis exacerbations (BEs).

RESULTS

Forty-seven patients (31.8%) were diagnosed as having CRS. Bronchiectasis etiologies did not vary statistically between CRS and no-CRS group. There was a trend towards non-statistically higher Bronchiectasis Severity Index [6.4±3.4 vs. 5.0(6.0), P = 0.19], a higher proportion of patients with BEs needing hospitalization before enrollment (48.9% vs. 29.7%, P = 0.13), poorer FVC [78.2±19.8% vs. 82.2(16.8)%, P = 0.54] and FEV1 [68.2±24.8% vs. 74.8(21.2)%, P = 0.29], a higher prevalence of Pseudomonas aeruginosa isolated (36.2% vs. 26.7%, P = 0.27) or colonized in sputum (36.2% vs. 21.8%, P = 0.12) and greater capsaicin cough sensitivity [C2: 3.9(123.0) μmol/L vs. 11.7(123.0) μmol/L, P = 0.81; C5: 62.5(996.0) μmol/L vs. 250.0(973.0) μmol/L, P = 0.32]. Patients with CRS had significantly greater risks of experiencing BEs during follow-up (P = 0.02 for negative binominal regression test).

CONCLUSION

Chinese adults with bronchiectasis appear to have a lower prevalence of CRS than that in western countries. There was a trend towards greater adverse impacts on bronchiectasis in patients with CRS. Studies with greater sample sizes might help to resolve this issue. In future clinical practice, physicians should be vigilant to the screening of concomitant CRS in bronchiectasis so as to better improve patient's healthcare. Our findings may be of clinical significance in that proper treatment of upper airway symptoms due to CRS will be the prevention of infection or re-infection of the tracheobronchial tree, which should be addressed for the future management of bronchiectasis.

Sputum matrix metalloproteinase-8 and -9 and tissue inhibitor of metalloproteinase-1 in bronchiectasis: clinical correlates and prognostic implications

BACKGROUND AND OBJECTIVE

The triplet of airway infection, inflammation and bronchial wall destruction associated with excessive matrix metalloproteinases (MMP) release and imbalance of tissue inhibitor metalloproteinase-1 (TIMP-1) is implicated in bronchiectasis. We sought to determine the associations between sputum MMP (MMP-8, MMP-9) and TIMP-1 and the severity of bronchiectasis; the utility of MMP in predicting risks of future bronchiectasis exacerbations (BE); and the changes in MMP levels during BE.

METHODS

We recruited 102 patients with stable bronchiectasis and 22 healthy subjects. For bronchiectasis patients, baseline measurements consisted of sputum inflammation and MMP measurements, bacterial culture, spirometry and chest high-resolution computed tomography (HRCT). Bronchiectasis patients were followed up for 1 year to determine the frequency of BE. Changes in MMP levels during BE were assessed in 36 bronchiectasis patients.

RESULTS

Sputum MMP-8, MMP-9 and MMP-9/TIMP-1 ratio in bronchiectasis patients were significantly increased compared with healthy subjects. MMP-8 and MMP-9 levels, but not TIMP-1, were positively correlated with clinical measures, including HRCT scores, spirometry and Bronchiectasis Severity Index. Seventy-nine bronchiectasis patients were included in survival analyses of BE. Lower levels of baseline MMP-9 were associated with reduced risks of and a longer time to the first BE during follow-up. MMP-8 and MMP-9, but not TIMP-1 or MMP-9/TIMP-1 ratio, were significantly heightened during BE.

CONCLUSIONS

Sputum MMP might be useful biomarkers for the assessment of bronchiectasis severity and the prediction of future risks of BE. Our results provide the rationales for the future clinical application of MMP inhibitors.

Effect of airway Pseudomonas aeruginosa isolation and infection on steady-state bronchiectasis in Guangzhou, China

BACKGROUND

Current status of Pseudomonas aeruginosa (PA) infection in clinically stable bronchiectasis in mainland China remains unclear.

OBJECTIVE

To compare the inflammation and lung function impairment in bronchiectasis patients isolated or infected with PA, potentially pathogenic microorganisms (PPMs) and commensals, and to identify factors associated with PA isolation and infection.

METHODS

Patients with steady-state bronchiectasis and healthy subjects were recruited. Peripheral blood and sputum were sampled to determine inflammatory markers and bacterial loads in steady-state bronchiectasis and health. Spirometry and diffusing capacity were also measured.

RESULTS

We enrolled 144 bronchiectasis patients and 23 healthy subjects. PA isolation and infection accounted for 44 and 39 patients, who demonstrated significant inflammatory responses and markedly impaired spirometry, but not diffusing capacity, compared with healthy subjects and patients isolated with other PPMs and commensals (all P<0.05). Except for heightened sputum inflammatory responses, there were no notable differences in serum inflammation and lung function as with the increased density of PA. Female gender [odds ratio (OR): 3.10 for PA isolation; OR: 3.74 for PA infection], 4 or more exacerbations within 2 years (OR: 3.74 for PA isolation, OR: 2.95 for PA infection) and cystic bronchiectasis (OR: 3.63 for PA isolation, OR: 4.47 for PA infection) were the factors consistently associated with PA isolation and infection.

CONCLUSIONS

PA elicits intense inflammation and lung function impairment in steady-state bronchiectasis. The density of PA does not correlate with most clinical indices. PA infection is associated with females, frequent exacerbations and cystic bronchiectasis.