Primary Airways Research Articles

Reduced sialylation of airway mucin impairs mucus transport by altering the biophysical properties of mucin

Mucus stasis is a pathologic hallmark of muco-obstructive diseases, including cystic fibrosis (CF). Mucins, the principal component of mucus, are extensively modified with hydroxyl (O)-linked glycans, which are largely terminated by sialic acid. Sialic acid is a negatively charged monosaccharide and contributes to the biochemical/biophysical properties of mucins. Reports suggest that mucin sialylation may be altered in CF; however, the consequences of reduced sialylation on mucus clearance have not been fully determined. Here, we investigated the consequences of reduced sialylation on the charge state and conformation of the most prominent airway mucin, MUC5B, and defined the functional consequences of reduced sialylation on mucociliary transport (MCT). Reduced sialylation contributed to a lower charged MUC5B form and decreased polymer expansion. The inhibition of total mucin sialylation de novo impaired MCT in primary human bronchial epithelial cells and rat airways, and specific α-2,3 sialylation blockade was sufficient to recapitulate these findings. Finally, we show that ST3 beta-galactoside alpha-2,3-sialyltransferase (ST3Gal1) expression is downregulated in CF and partially restored by correcting CFTR via Elexacaftor/Tezacaftor/Ivacaftor treatment. Overall, this study demonstrates the importance of mucin sialylation in mucus clearance and identifies decreased sialylation by ST3Gal1 as a possible therapeutic target in CF and potentially other muco-obstructive diseases.

Reduced Sialylation of Airway Mucin Impairs Mucus Transport by Altering the Biophysical Properties of Mucin.

Mucus stasis is a pathologic hallmark of muco-obstructive diseases, including cystic fibrosis (CF). Mucins, the principal component of mucus, are extensively modified with hydroxyl (O)-linked glycans, which are largely terminated by sialic acid. Sialic acid is a negatively charged monosaccharide and contributes to the biochemical/biophysical properties of mucins. Reports suggest that mucin sialylation may be altered in CF; however, the consequences of reduced sialylation on mucus clearance have not been fully determined. Here, we investigated the consequences of reduced sialylation on the charge state and conformation of the most prominent airway mucin, MUC5B, and defined the functional consequences of reduced sialylation on mucociliary transport (MCT). Reduced sialylation contributed to a lower charged MUC5B form and decreased polymer expansion. The inhibition of total mucin sialylation de novo impaired MCT in primary human bronchial epithelial cells and rat airways, and specific α-2,3 sialylation blockade was sufficient to recapitulate these findings. Finally, we show that ST3 beta-galactoside alpha-2,3-sialyltransferase (ST3Gal1) expression is downregulated in CF and partially restored by correcting CFTR via Elexacaftor/Tezacaftor/Ivacaftor treatment. Overall, this study demonstrates the importance of mucin sialylation in mucus clearance and identifies decreased sialylation by ST3Gal1 as a possible therapeutic target in CF and potentially other muco-obstructive diseases.

The efficacy of mass screening for chronic obstructive pulmonary disease using screening questionnaires in a medical health check-up population

Chronic obstructive pulmonary disease (COPD) is a preventable and treatable disease, highlighting the need for efficient screening strategies to identify patients with COPD. However, there is little evidence regarding the efficacy of mass screening for COPD, and no epidemiological studies on COPD have been conducted in the Shikoku region of Japan. In this cross-sectional study, we originally investigated the efficacy of mass screening for COPD among community residents in the aforementioned region using two COPD screening questionnaires. From July 2018 through January 2019, 688 participants were enrolled. COPD was diagnosed using the Global Initiative for the Chronic Obstructive Lung Disease criteria. Twenty-one patients were newly diagnosed with COPD and 19 (90.5%) had early stages COPD. The prevalence of COPD in this study was 3.1%. The COPD Population Screener (COPD-PS) questionnaire and the International Primary Care Airways Guidelines (IPAG) questionnaire had extremely high negative predictive values in discriminating participants with COPD from those without. The scores of both questionnaires were correlated with spirometric tests and with each other. The COPD-PS questionnaire had significantly better specificity and area under the receiver operating characteristic curve value than the IPAG questionnaire. Moreover, only the COPD-PS questionnaire was identified as an independent factor for predicting COPD diagnosis in the multivariate analysis. Mass screening for COPD using screening questionnaires, particularly the COPD-PS questionnaire, might be useful to identify the early stages of COPD in a medical health check-up population.

Sex Differences in the International Primary Care Airways Group Questionnaire for Screening of Chronic Obstructive Pulmonary Disease: A Retrospective, Cross-Sectional Study.

Background and ObjectiveThe International Primary Airways Group (IPAG) questionnaire is a useful tool for screening for chronic obstructive pulmonary disease. The cut-off score of the IPAG questionnaire is investigated in Japan. However, its validity has not been examined according to sex, which was the aim of this study.MethodsWe included 4364 participants aged 40 years or older, all current and ex-smokers and never-smokers, who completed the IPAG questionnaire and underwent spirometry. The IPAG questionnaire consists of eight items and the cut-off score is set to 17. We calculated the odds ratios of airflow limitation for each of the eight questions, by sex. We performed receiver operating characteristic analysis, calculating the area under the curve, sensitivity, and specificity for each sex.ResultsFor both men (n=2784) and women (n=1580), only three questions were independent risk factors of airflow limitation. The odds ratios for age (≥70 years), wheezing, and smoking history (≥50 pack-years) were 10.61, 3.50, and 2.40, respectively, for men (all p<0.001), and 4.30 (p<0.001), 2.32 (p=0.026), and 5.69 (p=0.014), respectively, for women. For men and women, the areas under the curve were 0.741 and 0.670, respectively. The sensitivity and specificity values, respectively, were as follows: 83.6% and 47.1% for men with a cut-off score of 17; 80.0% and 53.7% for men with a cut-off score of 18; 56.7%, and 65.9% for women with a cut-off score of 17; and 76.7% and 43.9% for women with a cut-off score of 15.ConclusionRegardless of sex, only three IPAG questions were deemed useful as screening for airflow limitation. The cut-off scores for men and women may be appropriately set at 18 and 15, respectively, in the Japanese population.

Airborne dust generation and dispersion profiles due to loaded LPDT haulage in decline of a highly mechanized underground lead–zinc ore mine

In underground metalliferous mines, declines serve as one of the primary intake airways. The intake air in declines gets contaminated by dust, gas, heat, and diesel particulate matter (DPM) generated due to the low-profile dump truck (LPDT) haulage. In this study, the generation and dispersion of airborne dust due to loaded LPDT haulage against ventilation air current in dry portion of decline of a fully mechanized underground lead–zinc ore mine are monitored using 15-channel real-time aerosol spectrometers. The airborne dust concentration in upstream (U) and downstream (D) sides, and generated by LPDT haulage (G=D-U) in decline are analysed in terms of cumulative and differential concentrations encompassing mass and percent proportions for different dust size ranges. The downstream airborne dust concentration is analysed in terms of occupational dust classification, such as alveolar (6%), thoracic (41%) and inhalable dust types. Moreover, empirical relations are developed for predicting the proportions of ≤ 10, 10–20, and >20 μ m size dust concentrations in the downstream airborne dust up to 300 m long decline. No significant studies have been conducted earlier on the generation and dispersion of airborne dust along the decline in mechanized underground metalliferous mines. This research can aid better understanding of the generation and dispersion behaviour of airborne dust, and enable the manufacturers, occupational hygienists, and mine environmentalists developing effective appliances and proper measures for the dust control in declines of underground metalliferous mines and tunnels. • Monitored upstream and downstream airborne dust generated by LPDT haulage in decline. • Analysed cumulative and differential dust generation/dispersion profiles for LPDT haulage. • Classified the airborne dust into alveolic, thoracic, and inhalable dust proportions. • Developed empirical relations to predict dust concentrations of various sizes in downstream.

A Novel Model-Based Questionnaire Based on Low-Dose CT Screening Data for Chronic Obstructive Pulmonary Disease Diagnosis in Shimane, Japan.

PurposeAlthough there have been many reports on the use of respiratory function tests and questionnaires for creating chronic obstructive pulmonary disease (COPD) questionnaires, there have been no reports on the effectiveness of questionnaires using computed tomography (CT) screening data. We aimed to validate the International Primary Care Airways Group (IPAG) questionnaire and to propose a novel COPD screening questionnaire based on the CT screening data of Japanese participants.Patients and MethodsLow-dose CT screening was performed for early detection of lung cancer and COPD since 2009 in Shimane, Japan, and clinical information was collected using an original questionnaire that included all the IPAG questionnaire items and eight additional items (for eg, on dyspnea) during CT screening. Participants with emphysema, smoking history, and respiratory symptoms were instructed to undergo a respiratory function test. The participants with the forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) <0.7 on the respiratory function test were diagnosed with COPD, and 11,458 participants underwent CT screening from 2013 to 2016 and were enrolled and filtered using <22.5 pack-years. Data from 3252 participants were selected for the final analysis. The receiver operating characteristic curve determined the best cutoff points for discriminating patients with COPD. The efficacy of the questionnaire items was determined using logistic regression analysis.ResultsThe best cutoff point for the Japanese IPAG questionnaire was 23. The logistic regression analysis revealed significant differences in the question items of “age”, “pack-year”, “cough”, “phlegm”, and “feeling of dyspnea”. COPD-CT questionnaire was developed based on the CT screening data. The COPD predicted value was determined using the regression model obtained in this study.ConclusionThe IPAG questionnaire had low specificity for discriminating COPD in Japanese patients. A novel questionnaire (COPD-CT) and the COPD predicted value based on the CT screening data was developed.

Ambient air quality and the risk for Chronic Obstructive Pulmonary Disease among Metro Manila Development Authority traffic enforcers in Metro Manila: An exploratory study

BackgroundAir pollution and poor ambient air quality are significantly related to multiple health risks. One associated disease is chronic obstructive pulmonary disease (COPD), a preventable disease with several contributing factors and one of the leading causes of morbidity/mortality locally and globally. A potentially high-risk population are traffic enforcers who are constantly exposed to air pollution. In the Philippines, the MMDA has the widest coverage in traffic management. The study determined the risk of COPD among Metro Manila Development Authority (MMDA) traffic enforcers in relation to ambient air quality level, as well as identified other factors that increase the risk of developing COPD. MethodsFifty-two MMDA traffic enforcers deployed in PM2.5 air quality sensor areas in Metro Manila from 2016 to 2018 were recruited through stratified sampling. The International Primary Airways Guidelines (IPAG) questionnaire was utilized to measure risk of COPD. Respiratory health and working history were obtained through questionnaires. Department of environment and natural resources provided PM2.5 ambient air quality data which aided in the construction of the Exposure-Month Index. Ordinal logistic regression was used to examine the association of PM2.5 together with the relevant factors and the risk of COPD. ResultsWe found statistically significant associations between PM2.5 and COPD among high risk category [odds risk (OR): 1.24, 95% confidence interval (CI): 1.07–1.44]. Age (Moderate, OR: 1.16, 95% CI: 0.98–1.38 and High, OR: 10.06, 95% CI: 4.02–25.17) and chest pain (Moderate, OR: 68.65, 95% CI: 1.71–2.75 × 103) were potential risk factors, whereas body mass index (BMI) (OR: 0.05, 95% CI: 0.01–0.53) exhibited protective effect. ConclusionsExposure to PM2.5 was associated with an increased risk of COPD among high-risk category MMDA traffic enforcers. Age and chest pain were potential risk factors to risk of COPD, whereas BMI exhibited a potential protective effect. Results of this study can be used for clinical management of high-risk populations, such that of MMDA traffic enforcers.

Oral prednisolone for acute lower respiratory tract infection in clinically unrecognised asthma: an exploratory analysis of the Oral Steroids for Acute Cough (OSAC) randomised controlled trial.

BackgroundAcute lower respiratory tract infection (ALRTI) is often treated in primary care with antibiotics. The recent Oral Steroids for Acute Cough (OSAC) randomised controlled trial (RCT) showed corticosteroids were not an effective alternative in adults without a diagnosis of asthma with ALRTI.AimTo investigate if corticosteroids are beneficial for ALRTI in patients with unrecognised asthma.Design & settingAn exploratory analysis was undertaken of the primary care OSAC trial.MethodA subgroup analysis was performed in patients who responded ‘yes’ to the following International Primary Care Airways Group (IPCAG) question: did you have wheeze and/or at least two of nocturnal cough or chest tightness or dyspnoea in the past year. Sensitivity analyses were carried out on those who answered ‘yes’ to wheeze and at least two of the nocturnal symptoms. The primary outcomes were as follows: duration of cough (0–28 days, minimum clinically important difference [MCID] of 3.79 days) and mean symptom severity score (range 0–6; MCID 1.66 units).ResultsIn total, 40 (10%) patients were included in the main analysis: mean age 49 years (standard deviation [SD] = 17.9), 52% male. Median cough duration was 3 days in both prednisolone (interquartile range [IQR] = 2–6 days) and placebo (IQR = 1–6 days) groups (adjusted hazard ratio [HR] = 1.10; 95% confidence interval [CI] = 0.47 to 2.54; P = 0.83), equating to 0.24 days longer in the prednisolone group (95% CI = 1.23 days shorter to 2.88 days longer). Mean symptom severity difference was –0.14 (95% CI = –0.78 to 0.49; P=0.65) comparing prednisolone with placebo. Similar findings were found in the sensitivity analysis.ConclusionNo evidence was found to support the use of corticosteroids for ALRTI in patients with clinically unrecognised asthma. Clinicians should not use the IPCAG questions to target oral corticosteroid treatment in patients with ALRTI.

Blocking Cell Extrusion Prevents Bronchoconstriction-Induced Airway Epithelial Damage and Inflammation

Asthma is a common disease characterized by airway constriction, excess mucus, and inflammation. We previously showed that cell crowding drives steady-state epithelial cell extrusion and cell death. Using ex vivo lung slices, we show that excessive crowding from methacholine-induced bronchoconstriction causes extensive cell extrusion leading to destruction of the airway epithelial barrier. In live mice, bronchoconstriction-induced extrusion caused airway epithelia damage and inflammation in secondary and tertiary airways. In primary airways, bronchoconstriction triggered mucus secretion by a mechanism reminiscent of extrusion. Reversing bronchoconstriction with albuterol failed to ameliorate these symptoms, whereas inhibiting the stretch-activated calcium channel, Piezo1, prevented extrusion, inflammation, and mucus secretion. Our findings propose a new etiology for asthma where the mechanical crowding from bronchoconstriction causes so much extrusion that it compromises the barrier, triggering subsequent inflammation. Furthermore, inhibiting extrusion, potentially with gadolinium, an inexpensive Piezo1 inhibitor, may prevent the asthma inflammatory cycle.

Morphogenesis of the kidney and lung requires branch-tip directed activity of the Adamts18 metalloprotease

Adamts18 encodes a secreted metalloprotease restricted to branch-tip progenitor pools directing the morphogenesis of multiple mammalian organs. Adamts18 was targeted to explore a potential role in branching morphogenesis. In the kidney, an arborized collecting system develops through extensive branching morphogenesis of an initial epithelial outgrowth of the mesonephric duct, the ureteric bud. Adamts18 mutants displayed a weakly penetrant phenotype: duplicated ureteric outgrowths forming enlarged, bi-lobed kidneys with an increased nephron endowment. In contrast, Adamts18 mutants showed a fully penetrant lung phenotype: epithelial growth was markedly reduced and early secondary branching scaled to the reduced length of the primary airways. Furthermore, there was a pronounced delay in the appearance of differentiated cell types in both proximal and distally positions of the developing airways. Adamts18 is closely related to Adamts16. In the kidney but not the lung, broad epithelial Adamts16 expression overlaps Adamts18 in branch tips. However, compound Adamts16/18 mutants displayed a comparable low penetrance duplicated ureteric phenotype, ruling out a possible role for Adamts16 as a functional modifier of the Adamts18 kidney phenotype. Given the predicted action of secreted Adamts18 metalloprotease, and broad expression of Adamts18 in branching organ systems, these findings suggest distinct requirements for matrix modelling in the morphogenesis of epithelial networks.

Comparison of Three Screening Questionnaires for Chronic Obstructive Pulmonary Disease in the Primary Care

Background: Even though the diagnosis of chronic obstructive pulmonary disease (COPD) is easy and based mainly on spirometry and symptoms, the prevalence of underdiagnosis is extremely high. The use of simple screening tools (e.g., questionnaires, hand-held spirometers) has been proved to be a simple method for case finding of COPD. Nevertheless the most appropriate target group of the general population has not been specified yet. Objectives: The aim of the present study was to compare 3 screening questionnaires among smokers aged >40 years in the primary care setting. Methods: We excluded all subjects with a previous medical diagnosis of bronchial asthma or chronic pulmonary disease other than COPD. All participants were in a stable clinical condition, filled in the International Primary Care Airways Group (IPAG) questionnaire, the COPD Population Screener (COPD-PS) questionnaire, and the Lung Function Questionnaire (LFQ) and underwent spirometry. Medical diagnosis of COPD was established by an experienced pulmonologist. Results: We studied 3,234 subjects during a 3.5-year period. COPD prevalence was 10.9% (52.1% underdiagnosis). All 3 questionnaires showed extremely high negative predictive values (94-96%), so in this case the diagnosis of COPD could be safely excluded. The area under the curve was similar across the 3 questionnaires (AUC_ROC: 0.794-0.809). The COPD-PS questionnaire demonstrated the highest positive predictive value (41%) compared to the other 2. On the other hand, the IPAG questionnaire and LFQ demonstrated higher sensitivities than COPD-PS resulting in lower percentages of missed cases. Conclusions: Three validated screening questionnaires for COPD demonstrated different diagnostic characteristics.

Creation and characterization of an airway epithelial cell line for stable expression of CFTR variants

BackgroundAnalysis of the functional consequences and treatment response of rare CFTR variants is challenging due to the limited availability of primary airways cells. MethodsA Flp recombination target (FRT) site for stable expression of CFTR was incorporated into an immortalized CF bronchial epithelial cell line (CFBE41o−). CFTR cDNA was integrated into the FRT site. Expression was evaluated by western blotting and confocal microscopy and function measured by short circuit current. RNA sequencing was used to compare the transcriptional profile of the resulting CF8Flp cell line to primary cells and tissues. ResultsFunctional CFTR was expressed from integrated cDNA at the FRT site of the CF8Flp cell line at levels comparable to that seen in native airway cells. CF8Flp cells expressing WT-CFTR have a stable transcriptome comparable to that of primary cultured airway epithelial cells, including genes that play key roles in CFTR pathways. ConclusionCF8Flp cells provide a viable substitute for primary CF airway cells for the analysis of CFTR variants in a native context.

Abstract 2993: The landscape of DNA allelic imbalance in the normal-appearing airway field of cancerization

Abstract The phenomenon of field cancerization has been previously postulated and observed in various cancers, including those of the lung. We have recently demonstrated that normal-appearing airway cells carry expression profiles that are often characteristic of the adjacent tumor. A better understanding of the molecular mechanisms that drive these field changes may provide important biological insights into lung cancer pathogenesis. Loss-of-heterozygosity (LOH) and other forms of acquired chromosomal alterations (allelic imbalance; AI) have an established and profound role in oncogenesis. However, the relationship between AI and field cancerization has not been studied comprehensively across the genome. Here we address this void by interrogating a rich collection of normal-appearing airways from non-small cell lung cancer (NSCLC) patients. We applied Illumina 1M SNP arrays to characterize whole genome copy number alterations in 435 samples from 45 early-stage NSCLC patients [31 adenocarcinomas (ADCs), 14 squamous cell carcinomas (SCCs)]. Each patient set comprised samples from the primary tumor and adjacent normal-appearing airways paired with blood cells and/or uninvolved normal lung tissue. A subset of these included brushings from ipsilateral large airways (mainstem bronchi) and from the nasal cavities as well as multi-region tumor biopsies for intra-tumoral analysis (on 22, 27, and 20 patients, respectively). To characterize the field in normal-appearing airways at a genome-wide scale, we applied a haplotype-based computational program, hapLOH, to profile AI events (loss, gain, copy neutral LOH) in a paired mode contrasting signals in the blood or normal lung. We detected 198 AI events in normal-appearing airways of 24 of 45 patients; 92% of these events were represented in the paired tumor. Of the 24 patients, 23 had events in the adjacent airway, 3 had events in the large airway, and no events were observed in nasal brushings, indicating a pronounced AI field gradient. We detected AI in the airways of approximately 43% of ADCs regardless of smoking status (3 of 7 smokers, 10 of 24 non-smokers), and 79% (11 of 14) of SCCs, clearly indicating squamous histology as a greater predictor of observing a genomic field effect (P &amp;lt; 0.03). The most frequently observed airway alterations were in 9p and 9q, affecting 13 smoker patients; interestingly, these were not observed in the non-smokers. Finally, we note that AI events were present in the adjacent airways of 4/5 (80%) of patients with recurrence and only in 20/40 patients without recurrence, signaling a profound prognostic value in studying the field of cancerization in NSCLC. Although preliminary, our findings suggest that chromosomal aberrations are common in the normal-appearing airway field of cancerization and can potentially provide insights into the biology of lung cancer pathogenesis and progression. Citation Format: Yasminka Jakubek, Wenhua Lang, Selina Vattathil, Melinda Garcia, Lili Huang, Wei Lu, Chi-Wan Chow, Zachary Weber, Gareth E. Davies, Carmen Behrens, Neda Kalhor, Cesar Moran, Junya Fujimoto, Reza J. Mehran, Jerry Fowler, Erik A. Ehli, Ignacio I. Wistuba, Paul Scheet, Humam Kadara. The landscape of DNA allelic imbalance in the normal-appearing airway field of cancerization. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2993. doi:10.1158/1538-7445.AM2015-2993

Discovery of a novel isoxazoline derivative of prednisolone endowed with a robust anti-inflammatory profile and suitable for topical pulmonary administration

A novel glucocorticoids series of (GCs), 6α,9α-di-Fluoro 3-substituted C-16,17-isoxazolines was designed, synthesised and their structure–activity relationship was evaluated with glucocorticoid receptor (GR) binding studies together with GR nuclear translocation cell-based assays. This strategy, coupled with in silico modelling analysis, allowed for the identification of Cpd #15, an isoxazoline showing a sub-nanomolar inhibitory potency (IC50=0.84nM) against TNFα-evoked IL-8 release in primary human airways smooth muscle cells. In Raw264.7 mouse macrophages, Cpd #15 inhibited LPS-induced NO release with a potency (IC50=6nM)>10-fold higher with respect to Dexamethasone. Upon intratracheal (i.t.) administration, Cpd #15, at 0.1μmol/kg significantly inhibited and at 1μmol/kg fully counteracted eosinophilic infiltration in a model of allergen-induced pulmonary inflammation in rats. Moreover, Cpd #15 proved to be suitable for pulmonary topical administration given its sustained lung retention (t1/2=6.5h) and high pulmonary levels (>100-fold higher than plasma levels) upon intratracheal administration in rats. In summary, Cpd #15 displays a pharmacokinetic and pharmacodynamic profile suitable for topical treatment of conditions associated with pulmonary inflammation such as asthma and COPD.

Lung transplant: An emerging challenge in the ICU

Lung transplantation shows good early results (1-year graft survival rate of 82.2%). Moreover, survival over a 5-year period is still high (50.5%). Lung transplantation is associated with substantial risks and severe complications that account for early mortality in the postoperative period (mainly primary graft failure, infection, bleeding and airways complications). However, long-term survival is determined primarily by the development of bronchiolitis obliterans syndrome (BOS), the effects of which may be manifested as progressive respiratory failure or by an increased risk of infection. In 2011, 235 lung transplants were conducted in Spain, being a big challenge in the postoperative period in 7 hospitals. Two physicians of each of these institutions, plus a coordinator discussed current challenges in a meeting in Santiago in October 2011 and launched a research cooperative network (PLUTO network). Some of the expositions will be reported in this series as reviews and original articles. This subgroup of immunosupressed patients is unique given that the transplanted organ is in constant direct contact with the environment and is deprived of its lymphatic drainage and nerve supply, rendering it unique susceptibility to infections. Even more, it has been suggested that over-immunosupression in lung-transplanted patients is real and is detectable in patients with infectious complications. Because the number of lung transplants has been increasing over the years, and has been accompanied by higher survival rates, we may anticipate that the number of lung transplanted patients readmitted to ICU will continue to rise in the forthcoming years. The study of this sub-population is, thereby, of extreme relevance and actuality. This issue of Medicina Intensiva begins

Resistin-like molecule- is a human airway remodelling mediator

Though implicated in vascular remodelling, a role for the resistin-like molecule (RELM)-β in human airway remodelling remains unexplored. We hypothesised that RELM-β expression is increased in the airways of asthmatics and regulates airways epithelial cell function. Expression of RELM-β in the bronchial mucosa and its concentrations in bronchoalveolar lavage (BAL) fluid from asthmatics and controls were measured by immunohistochemistry and ELISA, respectively. Proliferation assays, Western blotting, ELISA and real-time PCR were employed to detect effects of RELM-β on airways epithelial cells. RELM-β expression was increased in the bronchial mucosa and BAL fluid of asthmatics compared with controls. In the asthmatics, the numbers of mucosal RELM-β+ cells correlated inversely with forced expiratory volume in 1 s (r=-0.531, p=0.016), while the numbers of epithelial RELM-β+ cells correlated positively with those of mucin (MUC)5AC+ cells. In vitro, interleukin-13 enhanced RELM-β expression by primary human airways epithelial cells, while RELM-β itself acted on these cells to induce proliferation, expression of MUC5AC, extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK)-phosphatidylinositol 3-kinase (PI3K)/Akt phosphorylation and elevated expression of transforming growth factor-β2, epidermal growth factor and vascular endothelial growth factor. RELM-β has the potential to contribute to airway remodelling in diseases such as asthma by acting on epithelial cells to increase proliferation, mucin and growth factor production, at least partly via ERK/MAPK-PI3K/Akt signalling pathways.

O2-4.4 Lower respiratory tract infection in early life is associated with worse lung function in adult life: prospective results from the Barry Caerphilly Growth (BCG) study

IntroductionRespiratory infections in childhood have been related to reduced adult lung function, but few studies have examined the timing and type of infection. We hypothesised that lower respiratory tract infections...

A combination of the IPAG questionnaire and PiKo-6® flow meter is a valuable screening tool for COPD in the primary care setting

To investigate the validity of the International Primary Care Airways Guidelines (IPAG) questionnaire and PiKo-6® (Ferraris Respiratory Europe Ltd.) flow meter as screening tools for diagnosing chronic obstructive pulmonary disease (COPD) in the primary care setting. The first 50 patients in 25 general practice offices completed the IPAG questionnaire and underwent spirometry with the handheld PiKo-6® flow meter. The results were compared with official spirometry parameters after bronchodilation. All participants had no previous medical diagnosis of respiratory diseases. Data from 1,078 out of 1,250 subjects (462 males, mean age 65.3 ± 11.4 years) were analysed. The percentage of smokers was 48.4% (38 ± 29 pack-years). COPD was diagnosed in 111 (10.3%) patients. In the subgroup of smokers the sensitivity and specificity for COPD diagnosis were 91% and 49%, respectively, for the IPAG questionnaire; 80% and 95% respectively for the PiKo-6® spirometer; and 72% and 97% for their combination. The negative predictive value of the questionnaire was 97%, whereas the positive predictive value of the questionnaire/ PiKo-6® combination was 82%. Using a cut-off score of 19 points for the IPAG questionnaire, we calculated the best combination of sensitivity (75%) and specificity (72%). The IPAG questionnaire and the hand-held PiKo-6® spirometer can be used in combination to increase the possibility of an early and accurate diagnosis of COPD in the primary care setting.

Fas Activation in Alveolar Epithelial Cells Induces KC (CXCL1) Release by a MyD88-Dependent Mechanism

Activation of the Fas/Fas ligand (FasL) system is associated with activation of apoptotic and proinflammatory pathways that lead to the development of acute lung injury. Previous studies in chimeric mice and macrophage-depleted mice suggested that the main effector cell in Fas-mediated lung injury is not a myeloid cell, but likely an epithelial cell. The goal of this study was to determine whether epithelial cells release proinflammatory cytokines after Fas activation, and to identify the relevant pathways. Incubation of the murine alveolar epithelial cell line, MLE-12, with the Fas-activating monoclonal antibody, Jo2, resulted in release of the CXC chemokine, KC, in a dose-dependent manner. KC release was not prevented by the pan-caspase inhibitor, zVAD.fmk. Silencing of the adaptor protein, MyD88, with small interfering (si)RNA resulted in attenuation of KC release in response to Jo2. Fas activation resulted in phosphorylation of the mitogen-activated kinases extracellular signal-regulated kinase (ERK) and c-Jun-N-terminal kinase (JNK), and pharmacologic inhibition of ERK and JNK attenuated KC release in a dose-response manner. Similarly, primary human small airways epithelial cells released IL-8 in response to soluble FasL, and this was abrogated by inhibition of JNK and ERK. In vivo confirmatory studies showed that MyD88-null mice are protected from Fas-induced acute lung injury. In summary, we conclude that Fas induces KC release in MLE-12 cells by a mechanism requiring MyD88, mitogen-activated protein kinases, and likely activator protein-1.

Detection and prevalence of chronic obstructive pulmonary disease in a cardiovascular clinic: Evaluation using a hand held FEV1/FEV6 meter and questionnaire

COPD is one of the leading causes of morbidity and mortality worldwide, and its prevalence continues to increase. Although spirometry is indispensable for the diagnosis of COPD, other simple and reliable tools are necessary for screening of COPD because spirometry is not widely available. This study investigated the usefulness of a combination of an electronic FEV₁/FEV₆ meter (PiKo-6) with a COPD questionnaire as a screening method in patients with cardiovascular diseases. The PiKo-6 and the COPD questionnaire of the International Primary Care Airways Group were used to screen patients attending a cardiovascular outpatient clinic. Patients with FEV₁/FEV₆ < 70% were defined as having airflow limitation. Patients diagnosed with airflow limitation underwent spirometry. Using data from the PiKo-6 and the COPD questionnaire, patients were assigned to a COPD group or a non-COPD group. The relationship between PiKo-6 measurements and spirometry was also evaluated. Among 753 patients, 82 (10.9%) showed airflow limitation when assessed with the PiKo-6. Of these patients, 79 (10.5%) were assigned to the COPD group. FEV₁, FEV₆ and FEV₁/FEV₆, as measured with the PiKo-6, correlated significantly with FEV₁, FVC and FEV₁/FVC, respectively, as measured by spirometry (r = 0.865, 0.751 and 0.57). Among the cardiovascular comorbidities, heart failure and ischaemic heart disease showed slightly stronger associations with airflow limitation (13.8% and 12.5%, respectively). Combination of the PiKo-6 with a COPD questionnaire may be a useful and feasible method of identifying undiagnosed COPD patients attending a cardiovascular outpatient clinic.