Sputum induction

The Added Value of Bronchoalveolar Lavage for Pulmonary Tuberculosis Diagnosis in High-Risk Hospitalized Patients with Negative Sputum Samples

Hospitalized patients with a high suspicion of pulmonary tuberculosis (HS-PTB) are isolated until a definite diagnosis can be determined. If doubt remains after negative sputum samples, bronchoscopy with bronchoalveolar lavage (BAL) is often sought. Still, evidence of the added value of BAL in this patient population is scarce. To address this issue, we included consecutive HS-PTB patients with negative sputum samples who underwent BAL between 2017 and 2018. Chest X-rays (CXR) and CT scans were evaluated by a chest radiologist blind to the final diagnosis. Independent predictors for PTB were assessed by multivariate regression, using all positive PTB patients between 2017 and 2019 (by sputum or BAL) as a control group (n = 41). Overall, 42 HS-PTB patients were included (mean age 51 ± 9, 36% female). BAL was a viable diagnostic for PTB in three (7%) cases and for other clinically relevant pathogens in six (14%). Independent predictors for PTB were ≥2 sub-acute symptoms (adjusted OR 3.18, 95% CI 1.04-9.8), CXR upper-lobe consolidation (AOR 8.70, 95% CI 2.5-29), and centrilobular nodules in chest CT (AOR 3.96, 95% CI 1.20-13.0, p = 0.02). In conclusion, bronchoscopy with BAL in hospitalized patients with HS-PTB had a 7% added diagnostic value after negative sputum samples. Our findings highlight specific predictors for PTB diagnosis that could be used in future controlled studies to personalize the diagnostic evaluation.

A five-gene qPCR signature can classify type 2 asthma comparably to microscopy of induced sputum from severe asthma patients

Asthma is a heterogenous disease characterized by airway inflammation and variable expiratory airflow limitation resulting in variable respiratory symptoms. Characterization of airway inflammation is important to choose the optimal treatment for severe asthma patients eligible for biological treatment. However, counting cells in induced sputum samples are a time-consuming process, highly dependent on personal skills. Replacing eosinophil and neutrophil cell counting with qPCR for transcripts of selected mast cell, and basophil genes may provide more reproducible results.

Aims

The objective of this study was to compare qPCR with microscopy in asthma endotyping.

Methods

A qPCR method measuring five mast cell/basophil genes was applied on induced sputum samples from 30 severe asthma patients and compared with microscopy. Target gene Ct-values (CPA3, GATA2, HDC, MS4A2, TPSAB1/TPSB2) were referenced to household β-actin Ct values as a measure of relative mRNA abundance of the target in each sample. Target/β-actin-ratios in eosinophilic and non-eosinophilic groups determined by microscopy with an eosinophil threshold of 3% in 400 cells were compared using Mann-Whitney U Test. Spearman´s correlations were used to test for correlation between targets vs. FENO and targets vs. blood eosinophil counts.

Results

The study demonstrated a statistical difference in relative mRNA abundance for four mast cell/basophil specific genes. CPA3, GATA2, HDC and MS4A2 were elevated in eosinophilic asthma versus non-eosinophilic asthma patients. The study found that GATA2, CPA3, MS4A2 and TPSAB1/TPSB2 transcripts are positively correlated with FENO. Neither the five mast cell genes nor the five-gene signature correlated with blood eosinophils. The five-gene signature with a target/β-actin-ratio cut-off ≥2 generated sensitivity = 87%, specificity = 94%, NPV = 88% and PPV = 92% compared to microscopy.

Conclusion

This study confirms the contribution of mast cells in the pathogenesis of EA and suggests that mast cell mRNA markers could be one of the biomarkers used to identify EA.

Inhaler Steroid Use Changes Oral and Airway Bacterial and Fungal Microbiome Profile in Asthma Patients

INTRODUCTION

The full spectrum of bacterial and fungal species in adult asthma and the effect of inhaled corticosteroid use is not well described. The aim was to collect mouthwash and induced sputum samples from newly diagnosed asthma patients in the pretreatment period and in chronic asthma patients while undergoing regular maintenance inhaled corticosteroid therapy, in order to demonstrate the bacterial and fungal microbiome profile.

METHODS

The study included 28 asthmatic patients on inhaler steroid therapy, 25 steroid-naive asthmatics, and 24 healthy controls. Genomic DNA was isolated from induced sputum and mouthwash samples. Analyses were performed using bacterial primers selected from the 16S rRNA region for the bacterial genome and "panfungal" primers selected from the 5.8S rRNA region for the fungal genome.

RESULTS

Dominant genera in mouthwash samples of steroid-naive asthmatics were Neisseria, Haemophilus, and Rothia. The oral microbiota of asthmatic patients on inhaler steroid treatment included Neisseria, Rothia, and Veillonella species. Abundant genera in induced sputum samples of steroid-naive asthma patients were Actinomyces, Granulicatella, Fusobacterium, Peptostreptococcus, and Atopobium. Sputum microbiota of asthma patients taking inhaler steroids were dominated by Prevotella and Porphyromonas. Mucor plumbeus and Malassezia restricta species were abundant in the airways of steroid-naive asthma patients. Choanephora infundibulifera and Malassezia restricta became dominant in asthma patients taking inhaled steroids.

CONCLUSION

The oral and airway microbiota consist of different bacterial and fungal communities in healthy and asthmatic patients. Inhaler steroid use may influence the composition of the oral and airway microbiota.

Sputum induction and its diagnostic applications in inflammatory airway disorders: a review

Sputum induction is a technique that covers the induction and the subsequent processing of the expectorate primarily for the analysis of cells and different inflammatory biomarkers present in the airways to further understand the pathophysiology of different inflammatory respiratory disorders such as asthma and chronic obstructive pulmonary disease (COPD) as well as the diagnosis of lung diseases such as lung cancer, tuberculosis, and Pneumocystis jirovecii pneumonia. It is a non-invasive, safe, cost-effective, and reliable technique reported to exhibit a high success rate. However, due to being technically demanding and time-consuming and having the need of employing trained staff, this technique is only used in restricted research centres and in limited centres of clinical use. When the sputum is collected after induction, the primary goal is to obtain a differential cell count and evaluate the molecular biomarkers of airway inflammation such as eosinophil cationic protein, eosinophil-derived neurotoxin, major basic protein, tryptase, cytokine production [e.g., interleukin (IL)-5], albumin, and fibrinogen. In addition, cytospins from the processed sputum are used for immunocytochemical staining of cellular products such as EG-2 reactive protein, granulocyte-macrophage colony-stimulating factor, tumour necrosis factor alpha, and IL-8 that play significant roles in understanding the pathophysiology of inflammatory airway diseases. Nowadays, this technique can be further used by performing an additional analysis such as flow cytometry and in situ hybridisation on the sputum supernatant to investigate more the immune response and pathophysiological process of such various respiratory diseases. In addition, the application of sputum fluid phase to assess the biomarkers could be used more routinely in pathological laboratories for diagnosing lung cancer, COPD, and asthma as well as for monitoring lung cancer progression and asthma and COPD treatment, allowing for early detection and a better treatment provided by the clinicians.

The application of multi-omics in the respiratory microbiome: Progresses, challenges and promises

The study of the respiratory microbiome has entered a multi-omic era. Through integrating different omic data types such as metagenome, metatranscriptome, metaproteome, metabolome, culturome and radiome surveyed from respiratory specimens, holistic insights can be gained on the lung microbiome and its interaction with host immunity and inflammation in respiratory diseases. The power of multi-omics have moved the field forward from associative assessment of microbiome alterations to causative understanding of the lung microbiome in the pathogenesis of chronic, acute and other types of respiratory diseases. However, the application of multi-omics in respiratory microbiome remains with unique challenges from sample processing, data integration, and downstream validation. In this review, we first introduce the respiratory sample types and omic data types applicable to studying the respiratory microbiome. We next describe approaches for multi-omic integration, focusing on dimensionality reduction, multi-omic association and prediction. We then summarize progresses in the application of multi-omics to studying the microbiome in respiratory diseases. We finally discuss current challenges and share our thoughts on future promises in the field.

Characterization of the lung microbiome and inflammatory cytokine levels in women exposed to environmental risk factors: A pilot study

INTRODUCTION

Lung microbiome dysbiosis affects the immune system balance and promotes lung inflammation. We aimed to characterize and compare the lung bacteriome composition and the cytokine profile in women with normal lung function exposed to risk factors for chronic lung diseases (tobacco smoking and biomass-burning smoke exposure).

METHODS

We included women with biomass-burning smoke exposure (BE, n = 11) and current smokers women (TS, n = 10). The bacteriome composition was performed in induced sputum, sequencing the 16 rRNA gene. Cytokine levels were measured using enzyme-linked immunosorbent assay multiplex assay in the supernatant of induced sputum. For quantitative variables, we used medians and minimum and maxim values. For the amplicon sequence variants (ASV) differential abundance testing between groups.

RESULTS

At the taxa level, the phylum Proteobacteria was found in a higher proportion in the TS group concerning BE (p = .045); however, after the false discovery rate adjustment, this difference was not retained (p = .288). We found a higher concentration of IL-1β in the TS group than in the BE group (248.6 vs. 177.9 pg/mL, p = .010). Women with high biomass-burning smoke exposure in an hour per day had a positive correlation with the abundance of Bacteroidota (ρ = 0.71, p = .014) and Fusobacteriota (ρ = 0.73, p = .011). FEV1/FVC had a positive correlation with an abundance of Bacteroidota, Proteobacteria, and Fusobacteria (ρ = 0.74, p = .009, ρ = 0.85, p = .001, and ρ = 0.83, p = .001, respectively). In tobacco smoking, women had a positive correlation (ρ = 0.77, p = .009) between cigarettes per day and Firmicutes' abundance.

CONCLUSION

Compared to biomass-burning smoke-exposed women, current smokers have poor lung function and high levels of IL-1β in sputum. Women with biomass-burning smoke exposure present an increased abundance of Bacteroidota and Fusobacteriota.

Gram Stain and Culture of Sputum Samples Detect Only Few Pathogens in Community-Acquired Lower Respiratory Tract Infections: Secondary Analysis of a Randomized Controlled Trial

Identification of the bacterial etiology of lower respiratory tract infections (LRTI) is crucial to ensure a narrow-spectrum, targeted antibiotic treatment. However, Gram stain and culture results are often difficult to interpret as they depend strongly on sputum sample quality. We aimed to investigate the diagnostic yield of Gram stain and culture from respiratory samples collected by tracheal suction and expiratory technique from adults admitted with suspected community-acquired LRTI (CA-LRTI). In this secondary analysis of a randomized controlled trial, 177 (62%) samples were collected by tracheal suction, and 108 (38%) by expiratory technique. We detected few pathogenic microorganisms, and regardless of sputum quality, there were no significant differences between the sample types. Common pathogens of CA-LRTI were identified by culture in 19 (7%) samples, with a significant difference between patients with or without prior antibiotic treatment (p = 0.007). The clinical value of sputum Gram stain and culture in CA-LRTI is therefore questionable, especially in patients treated with antibiotics.

Upper airway disease diagnosis as a predictive biomarker of therapeutic response to biologics in severe asthma

Asthma is a heterogeneous disease sharing airway instability but with different biology, risk factors, and response-to-therapy patterns. Biologics have revolutionized the one-size-fits-to-all approach to personalized medicine in severe asthma (SA), which relies on the identification of biomarkers that define distinct endotypes. Thus, blood eosinophils and, to some extent, exhaled nitric oxide (FeNO) can predict the response to approved anti-type 2 (T2) biologics (anti-IgE, anti-IL-5, and anti-IL-4R alpha), whereas age at onset and comorbidities such as anxiety/depression, obesity, reflux, and upper airway disease (UAD) also influence therapeutic responses in SA. In this article, focusing on the predictive value of biomarkers for the therapeutic response to biologics in SA, we first summarize the level of prediction achieved by T2 biomarkers (blood eosinophils, FeNO) and then review whether data support the predictive value of upper airway diagnosis on such outcomes. Post hoc analysis of most studies with T2 biologics suggests that chronic rhinosinusitis with nasal polyps (CRSwNP) and, to a lower extent, allergic rhinitis may help in predicting clinical response. Considering that T2 biologics are now also approved for the treatment of severe CRSwNP, diagnosis of upper airway disease is a key step in determining eligibility for such therapy.

A case of atopic cough with aphonia showed a prominent response to a histamine H1 receptor antagonist

A 33-year-old woman admitted to our hospital for further examination of severe non-productive cough lasting for about two months. Her symptom did not ameliorate by treatments including long acting β2 agonists. She had a medical history of drug allergy to non-steroidal anti-inflammatory drugs. At the initial visit, she could not speak at all and communicated with us in writing. Chest auscultation revealed no wheezes, rhonchi and other crackles. Laboratory findings showed a mild eosinophilia with normal total and specific serum immunoglobulin E. The results of an electrocardiogram, a chest X-ray and a chest CT were unremarkable. A fractional exhaled nitric oxide value was within normal limit. Based on these observations, a diagnosis of atopic cough (AC) was suspected, and we started treatment with a histamine H1 receptor antagonist (H1-RA). She had become able to speak again in association with complete disappearance of cough by eight-weeks after treatment initiation, and her symptoms did not recur even after cessation of treatment. By the confirmation of remarkable clinical improvement in response to a H1-RA, a diagnosis of AC was made. To the best of our knowledge, this is the first report of an AC patient who presented severe cough with aphonia. J. Med. Invest. 70 : 281-284, February, 2023.

CC16 as an Inflammatory Biomarker in Induced Sputum Reflects Chronic Obstructive Pulmonary Disease (COPD) Severity

Purpose

The progression of an abnormal inflammatory response plays a crucial role in the lung function decline of chronic obstructive pulmonary disease (COPD) patients. Compared to serum biomarkers, inflammatory biomarkers in induced sputum would be a more reliable reflection of inflammatory processes in the airways.

Patients and Methods

A total of 102 COPD participants were divided into a mild-to-moderate group (FEV1%pred≥ 50%, n=57) and a severe-to-very-severe group (FEV1%pred<50%, n=45). We measured a series of inflammatory biomarkers in induced sputum and analyzed their association with lung function and SGRQ in COPD patients. To evaluate the relationship between inflammatory biomarkers and the inflammatory phenotype, we also analyzed the correlation between biomarkers and airway eosinophilic phenotype.

Results

We found increased mRNA levels of MMP9, LTB4R, and A1AR and decreased levels of CC16 mRNA in induced sputum in the severe-to-very-severe group. After adjustment for age, sex and other biomarkers, CC16 mRNA expression was positively associated with FEV1%pred (r=0.516, p=0.004) and negatively correlated with SGRQ scores (r=-0.3538, p=0.043). As previously known, decreased CC16 was related to the migration and aggregation of eosinophils in airway. It was also found that CC16 had a moderate negative correlation with the eosinophilic inflammation in airway (r=-0.363, p=0.045) in our COPD patients.

Conclusion

Low CC16 mRNA expression levels in induced sputum were associated with low FEV1%pred and a high SGRQ score in COPD patients. Sputum CC16 as a potential biomarker for predicting COPD severity in clinical practice might attribute to the involvement of CC16 in airway eosinophilic inflammation.

Using induced sputum method in clinical practice in patients with bronchial asthma

This article presents an overview of modern statements of the induced sputum method; detailed description of the methods and protocols for taking sputum in adults and children, methods for processing the obtained substance. The paper describes in detail the features of the cellular composition of induced sputum in healthy individuals and in patients with bronchial asthma, emphasizes the importance of the eosinophilia level as a prognostic and diagnostic criterion of asthma and also determines the functions of other induced sputum cells such as neutrophils, macrophages, basophils. The article is illustrated with photographs of sputum microscopy. In addition to sputum cytology, we give accent to the possibility of using other research methods such as an identification of viral and bacterial pathogens, genomics, proteomics, lipidomics, metabolomics, determination of the concentration of various mediators in the sputum supernatant. The paper presents the ideas on biochemical inflammatory markers and remodelling of the respiratory tract in asthma, which can be determined in sputum (C3a anaphylatoxin, clusterin, periostin, eosinophil-derived neurotoxin, folliculin). In addition, we summarize the information on inflammatory phenotypes of bronchial asthma, emphasize their variability and modification depending on the period of the disease, prescribed treatment, intercurrent respiratory infections, and smoking. The article also presents detailed characteristics of eosinophilic, neutrophilic, mixed and small granulocyte phenotypes of bronchial asthma, and describes the most frequent correlations of phenotypes with the severity and course of the disease, with lung function parameters and other indicators. The paper gives an account of the possibilities of using the induced sputum method for a comprehensive assessment of the course, asthma controllability and the effectiveness of drug therapy, as well as for a personalized selection of an antiinflammatory drug considering the inflammatory phenotype.

Expiratory Technique versus Tracheal Suction to Obtain Good-Quality Sputum from Patients with Suspected Lower Respiratory Tract Infection: A Randomized Controlled Trial

Microbiological diagnostics of good-quality sputum samples are fundamental for infection control and targeted treatment of lower respiratory tract infections (LRTI). This study aims to compare the expiratory technique and tracheal suction on the quality of sputa from adults acutely hospitalized with suspected LRTI. We performed an open-label, randomized controlled trial. Patients were randomized to sputum sampling by tracheal suction (standard care) or the expiratory technique. The primary outcome was quality of sputum evaluated by microscopy and was analysed in the intention-to-treat population. The secondary outcomes were adverse events and patients experience. In total, 280 patients were assigned to tracheal suction (n = 141, 50.4%) or the expiratory technique (n = 139, 49.6%). Sputum samples were collected from 122 (86.5%) patients with tracheal suction and 67 (48.2%) patients with expiratory technique. Good-quality sputa were obtained more often with tracheal suction than with expiratory technique (odds ratio 1.83 [95% CI 1.05 to 3.19]; p = 0.035). There was no statistical difference in adverse events (IRR 1.21 [95% CI, 0.94 to 1.66]; p = 0.136), but patient experience was better in the expiratory technique group (p < 0.0001). In conclusion, tracheal suction should be considered a routine procedure in emergency departments for patients with suspected LRTI.

Critical evaluation of asthma biomarkers in clinical practice

The advent of personalized medicine has revolutionized the whole approach to the management of asthma, representing the essential basis for future developments. The cornerstones of personalized medicine are the highest precision in diagnosis, individualized prediction of disease evolution, and patient-tailored treatment. To this aim, enormous efforts have been established to discover biomarkers able to predict patients' phenotypes according to clinical, functional, and bio-humoral traits. Biomarkers are objectively measured characteristics used as indicators of biological or pathogenic processes or clinical responses to specific therapeutic interventions. The diagnosis of type-2 asthma, prediction of response to type-2 targeted treatments, and evaluation of the risk of exacerbation and lung function impairment have been associated with biomarkers detectable either in peripheral blood or in airway samples. The surrogate nature of serum biomarkers, set up to be less invasive than sputum analysis or bronchial biopsies, has shown several limits concerning their clinical applicability. Routinely used biomarkers, like peripheral eosinophilia, total IgE, or exhaled nitric oxide, result, even when combined, to be not completely satisfactory in segregating different type-2 asthma phenotypes, particularly in the context of severe asthma where the choice among different biologics is compelling. Moreover, the type-2 low fraction of patients is not only an orphan of biological treatments but is at risk of being misdiagnosed due to the low negative predictive value of type-2 high biomarkers. Sputum inflammatory cell analysis, considered the highest specific biomarker in discriminating eosinophilic inflammation in asthma, and therefore elected as the gold standard in clinical trials and research models, demonstrated many limits in clinical applicability. Many factors may influence the measure of these biomarkers, such as corticosteroid intake, comorbidities, and environmental exposures or habits. Not least, biomarkers variability over time is a confounding factor leading to wrong clinical choices. In this narrative review, we try to explore many aspects concerning the role of routinely used biomarkers in asthma, applying a critical view over the "state of the art" and contemporarily offering an overview of the most recent evidence in this field.

Peripheral blood transcriptomic clusters uncovered immune phenotypes of asthma

BACKGROUND

Transcriptomic analysis has been used to elucidate the complex pathogenesis of heterogeneous disease and may also contribute to identify potential therapeutic targets by delineating the hub genes. This study aimed to investigate whether blood transcriptomic clustering can distinguish clinical and immune phenotypes of asthmatics, and microbiome in asthmatics.

METHODS

Transcriptomic expression of peripheral blood mononuclear cells (PBMCs) from 47 asthmatics and 21 non-asthmatics was measured using RNA sequencing. A hierarchical clustering algorithm was used to classify asthmatics. Differentially expressed genes, clinical phenotypes, immune phenotypes, and microbiome of each transcriptomic cluster were assessed.

RESULTS

In asthmatics, three distinct transcriptomic clusters with numerously different transcriptomic expressions were identified. The proportion of severe asthmatics was highest in cluster 3 as 73.3%, followed by cluster 2 (45.5%) and cluster 1 (28.6%). While cluster 1 represented clinically non-severe T2 asthma, cluster 3 tended to include severe non-T2 asthma. Cluster 2 had features of both T2 and non-T2 asthmatics characterized by the highest serum IgE level and neutrophil-dominant sputum cell population. Compared to non-asthmatics, cluster 1 showed higher CCL23 and IL1RL1 expression while the expression of TREML4 was suppressed in cluster 3. CTSD and ALDH2 showed a significant positive linear relationship across three clusters in the order of cluster 1 to 3. No significant differences in the diversities of lung and gut microbiomes were observed among transcriptomic clusters of asthmatics and non-asthmatics. However, our study has limitations in that small sample size data were analyzed with unmeasured confounding factors and causal relationships or function pathways were not verified.

CONCLUSIONS

Genetic clustering based on the blood transcriptome may provide novel immunological insight, which can be biomarkers of asthma immune phenotypes. Trial registration Retrospectively registered.

The human lung microbiome-A hidden link between microbes and human health and diseases

Once thought to be sterile, the human lung is now well recognized to harbor a consortium of microorganisms collectively known as the lung microbiome. The lung microbiome is altered in an array of lung diseases, including chronic lung diseases such as chronic obstructive pulmonary disease, asthma, and bronchiectasis, acute lung diseases caused by pneumonia, sepsis, and COVID-19, and other lung complications such as those related to lung transplantation, lung cancer, and human immunodeficiency virus. The effects of lung microbiome in modulating host immunity and inflammation in the lung and distal organs are being elucidated. However, the precise mechanism by which members of microbiota produce structural ligands that interact with host genes and pathways remains largely uncharacterized. Multiple unique challenges, both technically and biologically, exist in the field of lung microbiome, necessitating the development of tailored experimental and analytical approaches to overcome the bottlenecks. In this review, we first provide an overview of the principles and methodologies in studying the lung microbiome. We next review current knowledge of the roles of lung microbiome in human diseases, highlighting mechanistic insights. We finally discuss critical challenges in the field and share our thoughts on broad topics for future investigation.

Treatment Resistance in Severe Asthma Patients With a Combination of High Fraction of Exhaled Nitric Oxide and Low Blood Eosinophil Counts

Background: Combining a fraction of exhaled nitric oxide (FeNO) and blood eosinophil count (B-EOS) may be a useful strategy for administration of biologics such as anti-IgE or anti-IL-5 to patients with type 2 inflammatory-predominant severe asthma and is important to be elucidated considering the increasing use of biologics.

Methods: This cross-sectional study analyzed the clinical data from 114 adult patients with severe asthma, who were treated at Saitama Medical University Hospital. The eligible patients were stratified into four subgroups defined by thresholds of FeNO and blood eosinophil (B-EOS) counts to detect sputum eosinophilia, using the receiver operating characteristic curve analysis. A total of 75 patients with optimal samples were stratified into four subtypes defined by thresholds of sputum eosinophilia and neutrophilia. Clinical characteristics, pattern of biologics, and distribution of sputum subtypes were analyzed in the stratified subclasses according to the FeNO and B-EOS thresholds. The asthma exacerbation (AE)-free time of the FeNO/B-EOS subgroups and any biologics treatment including anti-IgE or anti-IL-5 use were examined using the Kaplan–Meier method. The hazard ratios (HRs) for AE-free time were examined using the Cox proportional hazard model.

Results: The optimal cutoff values for prediction of sputum eosinophilia were defined as ≥2.7% wherein for FeNO as ≥27 ppb and B-EOS as ≥265/µL were considered. The high-FeNO subgroups showed significant high total IgE, compared with the low FeNO. The high-FeNO/high-B-EOS and the high-FeNO/low-B-EOS subgroups showed the largest prevalence of mepolizumab and benralizumab use among the other FeNO/B-EOS, respectively. The high-FeNO/low-B-EOS showed the largest frequency of AEs, high HR, and the shortest AE-free time, among the other FeNO/B-EOS. The sputum eosinophil-predominant subtype was the great majority in the high FeNO/high B-EOS. A diverse distribution of sputum leukocyte-predominant subtype was observed in the other FeNO/B-EOS. The subsequent AE-free time and its HR were comparable among the biologics use groups.

Conclusion: The strategy of classifying severe asthma based on the combination of FeNO and B-EOS proposes particular refractory type 2 severe asthma and underlying airway inflammation as a feasible trait for optimal biologics use.

The Immune Mechanisms of Severe Equine Asthma-Current Understanding and What Is Missing

Severe equine asthma is a chronic respiratory disease of adult horses, occurring when genetically susceptible individuals are exposed to environmental aeroallergens. This results in airway inflammation, mucus accumulation and bronchial constriction. Although several studies aimed at evaluating the genetic and immune pathways associated with the disease, the results reported are inconsistent. Furthermore, the complexity and heterogeneity of this disease bears great similarity to what is described for human asthma. Currently available studies identified two chromosome regions (ECA13 and ECA15) and several genes associated with the disease. The inflammatory response appears to be mediated by T helper cells (Th1, Th2, Th17) and neutrophilic inflammation significantly contributes to the persistence of airway inflammatory status. This review evaluates the reported findings pertaining to the genetical and immunological background of severe equine asthma and reflects on their implications in the pathophysiology of the disease whilst discussing further areas of research interest aiming at advancing treatment and prognosis of affected individuals.

Performance of a Real Time PCR for Pneumocystis jirovecii Identification in Induced Sputum of AIDS Patients: Differentiation between Pneumonia and Colonization

Pneumocystis jirovecii pneumonia (PcP) remains an important cause of morbimortality worldwide and a diagnostic challenge. Conventional methods have low accuracy, hardly discriminating colonization from infection, while some new high-cost or broncho-alveolar lavage-based methods have limited usefulness in developing countries. Quantitative PCR (qPCR) tests may overcome these limitations due to their high accuracy, possibility of automation, and decreasing cost. We evaluated an in-house qPCR targeting the fungus mtSSU gene using induced sputum. Sensitivity of the assay (ten target gene copies/assay) was determined using recombinant plasmids. We prospectively studied 86 AIDS patients with subacute respiratory symptoms in whom PcP was suspected. qPCR results were determined as quantification cycles (Cq) and compared with a qualitative PCR performed in the same IS, serum 1,3-β-D-Glucan assay, and a clinical/laboratory/radiology index for PcP. The qPCR clustered the patients in three groups: 32 with Cq ≤ 31 (qPCR+), 45 with Cq ≥ 33 (qPCR-), and nine with Cq between 31-33 (intermediary), which, combined with the other three analyses, enabled us to classify the groups as having PcP, not P. jirovecii-infected, and P. jirovecii-colonized, respectively. This molecular assay may contribute to improve PcP management, avoiding unnecessary treatments, and our knowledge of the natural history of this infection.

Inflammatory Phenotypes of Cough Variant Asthma as Response Predictors to Anti-Asthmatic Therapy

Background

Eosinophilic inflammatory phenotype was thought to be the most common phenotype of cough variant asthma (CVA), nevertheless other phenotypes were also reported.

Purpose

The study aimed to analyze the inflammatory phenotypes of CVA in relation to treatment response to the stepwise anti-asthmatic treatment.

Patients and Methods

The study included 45 patients with chronic cough (CC) and suspicion of CVA (normal chest X-ray, presence of bronchial hyperresponsiveness and no history of wheezing or dyspnea) in whom induced sputum was successfully collected. Based on the cellular composition of the sputum, patients were divided into major inflammatory phenotypes: eosinophilic, neutrophilic, paucigranulocytic or mixed granulocytic. A stepwise treatment, including inhaled corticosteroids with long-acting β₂-agonist, montelukast and short-term therapy with prednisone was initiated. Good treatment response was defined as the reduction in cough severity at least 20 mm from the baseline in visual analogue scale and improvement in cough-related quality of life assessed by the Leicester cough questionnaire at least 1.3 points after any of three steps.

Results

Finally, 40/45 (88.9%) patients improved after therapy. Eosinophilic asthma was found in 13/40 (32.5%) patients, neutrophilic in 6/40 (15.0%) and paucigranulocytic pattern in 21/40 (52.5%) patients. No one demonstrated a mixed granulocytic phenotype. The response to the treatment was similar in all groups. However, the reduction in cough severity was inversely related to the percentage of sputum neutrophils (r = −0.44, P = 0.003). We showed that the percentage of neutrophils in sputum >46% may be considered as a predictor of poor response to anti-asthmatic therapy.

Conclusion

The diversity of inflammatory phenotypes with paucigranulocytic preponderance was found in subjects with CVA. The response to anti-asthmatic treatment in patients with CVA was not related to the inflammatory phenotype. High neutrophil count in sputum may predict poor response to anti-asthmatic therapy in patients with CC and bronchial hyperresponsiveness.

Airway inflammation and dysbiosis in antibody deficiency despite the presence of IgG

BACKGROUND

Patients with antibody deficiency suffer chronic respiratory symptoms, recurrent exacerbations and progressive airways disease despite systemic replacement of Immunoglobulin G. Little is known about the respiratory tract biology of these patients.

OBJECTIVE

To measure immunoglobulin levels, inflammatory cytokines and mediators of tissue damage in serum and sputum from patients with antibody deficiency and healthy controls; to analyse the respiratory microbiome in the same cohorts.

METHODS

We obtained paired sputum and serum samples from 31 immunocompetent subjects and 67 antibody deficient patients, the latter divided on computed tomography scan appearance into 'abnormal airways' (bronchiectasis or airway thickening) or 'normal airways'. We measured inflammatory cytokines, immunoglobulin levels, neutrophil elastase, matrix-metalloproteinase-9, urea, albumin and total protein levels using standard assays. We employed V3-V4 region 16S sequencing for microbiome analysis.

RESULTS

Immunodeficient patients had markedly reduced Immunoglobulin A in sputum but higher concentrations of Immunoglobulin G compared to healthy controls. Inflammatory cytokines and tissue damage markers were higher in immunodeficient patients, who also exhibited dysbiosis with over-representation of pathogenic taxa and significantly reduced alpha diversity compared to immunocompetent individuals. These differences were seen regardless of airway morphology. Sputum matrix metalloproteinase-9 and elastase correlated inversely with alpha diversity in the antibody deficient group, as did sputum Immunoglobulin G, which correlated positively with several inflammatory markers, even after correction for albumin levels.

CONCLUSION

Patients with antibody deficiency, even with normal lung imaging, exhibit inflammation and dysbiosis in their airways despite higher levels of Immunoglobulin G compared to healthy controls.

Effectiveness of expiratory technique and induced sputum in obtaining good quality sputum from patients acutely hospitalized with suspected lower respiratory tract infection: a statistical analysis plan for a randomized controlled trial

Background

Targeted antimicrobial treatment is essential to avoid unnecessary use of broad-spectrum antibiotics and antimicrobial resistance. Targeted treatment relies on a precise microbiological diagnosis — in pneumonia, this poses a challenge as the usefulness of Gram stains and cultures is highly dependent on the quality of the sputum sample.

This study aims to examine adverse effects and quality of sputum samples obtained by expiratory techniques (forced expiratory technique and sputum induction) compared with tracheal suction. The hypothesis is that expiratory techniques are non-inferior to tracheal suction in obtaining samples from the lower respiratory tract. This statistical analysis plan (SAP) describes the study design, method, and data analysis of the trial to increase transparency, avoid reporting bias or data-driven analysis and increase the study’s reproducibility.

Method

The design is a pragmatic, non-inferiority, parallel-arm randomized controlled trial including 280 patients admitted with suspected lower respiratory infection to two emergency departments. Patients are randomized to a usual care group, where sputum samples are collected by tracheal suction or to an intervention group where sputum samples are collected by forced expiratory technique and sputum induction. The statistical analysis will follow an intention-to-treat protocol. This SAP is developed and submitted before the end of recruitment, database closure, and statistical analyses.

Discussion

The results of this study will provide valuable knowledge to clinical practice by comparing adverse effects and sputum sample quality associated with different sample methods.

Trial registration

Clinicaltrials.gov, NCT04595526. Submitted on October 19, 2020

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05639-1.

Does bronchial hyperresponsiveness predict a diagnosis of cough variant asthma in adults with chronic cough: a cohort study

Bronchial hyperresponsiveness is a typical, but non-specific feature of cough variant asthma (CVA). This study aimed to determine whether bronchial hyperresponsiveness may be considered as a predictor of CVA in non-smoking adults with chronic cough (CC). The study included 55 patients with CC and bronchial hyperresponsiveness confirmed in the methacholine provocation test, in whom an anti-asthmatic, gradually intensified treatment was introduced. The diagnosis of CVA was established if the improvement in cough severity and cough-related quality of life in LCQ were noted.The study showed a high positive predictive value of bronchial hyperresponsiveness in this population. Cough severity and cough related quality of life were not related to the severity of bronchial hyperresponsiveness in CVA patients. A poor treatment outcome was related to a low baseline capsaicin threshold and the occurrence of gastroesophageal reflux-related symptoms. In conclusion, bronchial hyperresponsiveness could be considered as a predictor of cough variant asthma in non-smoking adults with CC.

A Novel Processing-Free Method for RNAseq Analysis of Spontaneous Sputum in Chronic Obstructive Pulmonary Disease

Background: Assessments of airways inflammation in patients with chronic obstructive pulmonary disease (COPD) require semi-invasive procedures and specialized sample processing know-how. In this study we aimed to set up and validate a novel non-invasive processing-free method for RNA sequencing (RNAseq) of spontaneous sputum samples collected from COPD patients.

Methods: Spontaneous sputum samples were collected and stabilized, with or without selection of plugs and with or without the use of a stabilizer specifically formulated for downstream diagnostic testing (PrimeStore® Molecular Transport Medium). After 8 days storage at ambient temperature RNA was isolated according to an optimized RNAzol® method. An average percentage of fragments longer than 200 nucleotides (DV₂₀₀) >30% and an individual yield >50 ng were required for progression of samples to sequencing. Finally, to assess if the transcriptome generated would reflect a true endotype of COPD inflammation, the outcome of single-sample gene-set enrichment analysis (ssGSEA) was validated using an independent set of processed induced sputum samples. Results: RNA extracted from spontaneous sputum using a stabilizer showed an average DV₂₀₀ higher than 30%. 70% of the samples had a yield >50 ng and were submitted to downstream analysis. There was a straightforward correlation in terms of gene expression between samples handled with or without separation of plugs. This was also confirmed by principal component analysis and ssGSEA. The top ten enriched pathways resulting from spontaneous sputum ssGSEA were associated to features of COPD, namely, inflammation, immune responses and oxidative stress; up to 70% of these were in common within the top ten enriched pathways resulting from induced sputum ssGSEA.

Conclusion: This analysis confirmed that the typical COPD endotype was represented within spontaneous sputum and supported the current method as a non-invasive processing-free procedure to assess the level of sputum cell inflammation in COPD patients by RNAseq analysis.

DNA Methylation-Based Age Prediction and Telomere Length Reveal an Accelerated Aging in Induced Sputum Cells Compared to Blood Leukocytes: A Pilot Study in COPD Patients

Aging is the predominant risk factor for most degenerative diseases, including chronic obstructive pulmonary disease (COPD). This process is however very heterogeneous. Defining the biological aging of individual tissues may contribute to better assess this risky process. In this study, we examined the biological age of induced sputum (IS) cells, and peripheral blood leukocytes in the same subject, and compared these to assess whether biological aging of blood leukocytes mirrors that of IS cells. Biological aging was assessed in 18 COPD patients (72.4 ± 7.7 years; 50% males). We explored mitotic and non-mitotic aging pathways, using telomere length (TL) and DNA methylation-based age prediction (DNAmAge) and age acceleration (AgeAcc) (i.e., difference between DNAmAge and chronological age). Data on demographics, life style and occupational exposure, lung function, and clinical and blood parameters were collected. DNAmAge (67.4 ± 5.80 vs. 61.6 ± 5.40 years; p = 0.0003), AgeAcc (-4.5 ± 5.02 vs. -10.8 ± 3.50 years; p = 0.0003), and TL attrition (1.05 ± 0.35 vs. 1.48 ± 0.21 T/S; p = 0.0341) are higher in IS cells than in blood leukocytes in the same patients. Blood leukocytes DNAmAge (r = 0.927245; p = 0.0026) and AgeAcc (r = 0.916445; p = 0.0037), but not TL, highly correlate with that of IS cells. Multiple regression analysis shows that both blood leukocytes DNAmAge and AgeAcc decrease (i.e., younger) in patients with FEV₁% enhancement (p = 0.0254 and p = 0.0296) and combined inhaled corticosteroid (ICS) therapy (p = 0.0494 and p = 0.0553). In conclusion, new findings from our work reveal a differential aging in the context of COPD, by a direct quantitative comparison of cell aging in the airway with that in the more accessible peripheral blood leukocytes, providing additional knowledge which could offer a potential translation into the disease management.

The Relevance of Small Airway Dysfunction in Asthma with Nocturnal Symptoms

Rationale

Small airway dysfunction (SAD) is a frequent feature of asthma that has been linked to disease severity and poor symptom control. However, little is known about the role of SAD in nocturnal asthma.

Objective

To study the association between the severity of SAD and frequency of nocturnal symptoms compared to conventional lung function testing.

Methods

We assessed the frequency of self-reported nocturnal symptoms through the asthma control test. We studied the impact of nocturnal asthma using the Asthma Quality of Life Questionnaire (AQLQ) and the Multidimensional Fatigue Inventory (MFI-20). We assessed the lung function using spirometry, body plethysmography, impulse oscillometry, single and multiple inert gas washout and measured markers of T2-inflammation (blood and sputum eosinophils; fractional exhaled nitric oxide (FeNo)). We stratified the patients according to the presence and frequency of nocturnal asthma.

Results

A total of 166 asthma patients were enrolled in the analysis. Eighty-seven patients (52%) reported to have nocturnal symptoms at least once in the last four weeks. The odds ratio of nocturnal asthma correlated with the severity of all non-spirometric measures of SAD, yet neither with airflow obstruction (FEV1 and FEV/FVC) nor with large airway resistance (R20). Patients with frequent nocturnal asthma (n = 29) had a numerical increase of T2 markers and more severe SAD, as indicated by all non-spirometric measures of SAD (all p-values < 0.05), worse overall asthma control, increased fatigue and reduced quality of life (all p-values < 0.01) compared to patients with infrequent nocturnal asthma (n = 58) or patients without nocturnal asthma (n = 79). We identified 63 patients without airflow obstruction, nearly 43% of them (n = 27) had nocturnal asthma. In this subgroup, only markers of air trapping and ventilation heterogeneity were significantly elevated and correlated with the frequency of nocturnal symptoms: LCI (Spearman’s coefficient = −0.42, p < 0.001), RV% (−0.32, p = 0.02).

Conclusion

SAD is closely associated to asthma with nocturnal symptoms. Spirometry might underestimate the broad spectrum of distal lung function impairments in this population of patients.

Comparative Analysis of Clinical Parameters and Sputum Biomarkers in Establishing the Relevance of Filamentous Fungi in Cystic Fibrosis

Background

The relationship between fungal culture (FC) positivity and airway inflammation in CF is largely unknown. Identifying the clinical significance of filamentous fungi in CF using both clinical parameters and biomarkers may change our antimicrobial therapeutic strategies.

Objectives

To investigate the clinical characteristics and airway biomarker profile in relation to the detection of filamentous fungi in respiratory samples obtained from CF patients.

Methods

A prospective cohort study over 24 months, including children and adults with CF. Participants provided sputum and/or bronchoalveolar lavage samples, which underwent processing for bacterial and fungal culture, leukocyte differential cell count and biomarker analysis for neutrophil elastase (NE), interleukin-8 (IL-8), galactomannan and tumor necrosis factor receptor type 2 (TNF-R2). We performed FC using neat sputum plugs, an approach shown to be more sensitive compared to routine laboratory testing.

Results

Sixty-one patients provided 76 respiratory samples (72 sputum and 4 BAL). Median age was 17 years (range 6 months-59 years). FC positivity was noted in 49% of the cohort. FC positivity was greater during pulmonary exacerbation compared to the stable state (67 versus 50%). Participants aged 5-30 years had a lower FEV1 within the FC positive group. A significant association between FC positivity and non-tuberculosis mycobacterial (NTM) culture was observed on non-parametric testing (p = 0.022) and regression analysis (p = 0.007). Exposure to indoor mold was a predictor for FC positivity (p = 0.047). There was a trend towards increased lung clearance index (LCI), bronchiectasis and intravenous antibiotic use in the FC positive group. There was no significant difference in biomarkers between FC positive and negative patients.

Conclusion

Aspergillus. fumigatus is the commonest filamentous fungi cultured from CF airways. We found no difference in the airway biomarker profile between FC positive and negative patients. The role of galactomannan and TNFR2 as fungal specific biomarkers in CF remains uncertain. FC positivity is associated with a lower FEV₁ in younger patients, a lower LCI, NTM positivity, bronchiectasis, and intravenous antibiotic exposure. Larger trials are needed to determine the role of galactomannan and TNF-R2 as potential fungal biomarkers in CF.

Extracellular Vesicles from Airway Secretions: New Insights in Lung Diseases

Lung diseases (LD) are one of the most common causes of death worldwide. Although it is known that chronic airway inflammation and excessive tissue repair are processes associated with LD such as asthma, chronic obstructive pulmonary disease (COPD) or idiopathic pulmonary fibrosis (IPF), their specific pathways remain unclear. Extracellular vesicles (EVs) are heterogeneous nanoscale membrane vesicles with an important role in cell-to-cell communication. EVs are present in general biofluids as plasma or urine but also in secretions of the airway as bronchoalveolar lavage fluid (BALF), induced sputum (IS), nasal lavage (NL) or pharyngeal lavage. Alterations of airway EV cargo could be crucial for understanding LD. Airway EVs have shown a role in the pathogenesis of some LD such as eosinophil increase in asthma, the promotion of lung cancer in vitro models in COPD and as biomarkers to distinguishing IPF in patients with diffuse lung diseases. In addition, they also have a promising future as therapeutics for LD. In this review, we focus on the importance of airway secretions in LD, the pivotal role of EVs from those secretions on their pathophysiology and their potential for biomarker discovery.

Relationship between Th17-mediated immunity and airway inflammation in childhood neutrophilic asthma

BACKGROUND

The pathogenetic mechanisms of neutrophilic asthma are not well understood now. Whether T helper (Th)17-mediated immunity contributes to the pathogenesis of neutrophilic asthma in human is still under investigation. The aim of this study was to explore the relationship between Th17-mediated immunity and airway inflammation in childhood neutrophilic asthma.

METHODS

Twenty-eight children with exacerbated asthma and without using any glucocorticoids were divided into three groups: eosinophilic asthma (EA, n = 12) group, neutrophilic asthma (NA, n = 10) group and paucigranulocytic asthma (PGA, n = 6) group according to the induced sputum cytology. Ten healthy children were recruited as healthy control (HC, n = 10) group. Peripheral Th17 and Th2 cells, and the expression of Ki-67 in peripheral Th17 cells were detected by flow cytometry. The mRNA expression of retinoic acid-related orphan receptor γt (RORγt) in peripheral blood mononuclear cells (PBMCs) was detected by qRT-PCR. The concentrations of IL-17, IL-8 and IL-5 in sputum, as well as IL-17 in plasma and culture supernatant of activated PBMCs were measured by ELISA.

RESULTS

The percentage of Th17 cells in peripheral Th cells, and the concentrations of IL-17, IL-8 in sputum, as well as IL-17 in culture supernatant of activated PBMCs were all increased in NA group, and positively correlated with neutrophil level in sputum and with each other. Also, the mRNA expression of RORγt in PBMCs and Ki-67 positivity in peripheral Th17 cells were both increased in NA group. The percentage of Th2 cells in peripheral Th cells, and the concentration of IL-5 in sputum were both increased in EA group, and positively correlated with eosinophil level in sputum and with each other.

CONCLUSIONS

Both Th17- and Th2-mediated immunity are involved in the pathogenesis of childhood asthma. There is predominance of Th17-mediated immunity and Th17 cells proliferation in childhood neutrophilic asthma.

The airways microbiome of individuals with asthma treated with high and low doses of inhaled corticosteroids

BACKGROUND

Inhaled corticosteroids (ICS) are the mainstay of asthma treatment, but evidence suggests a link between ICS usage and increased rates of respiratory infections. We assessed the composition of the asthmatic airways microbiome in asthma patients taking low and high dose ICS and the stability of the microbiome over a 2 week period.

METHODS

We prospectively recruited 55 individuals with asthma. Of these, 22 were on low-dose ICS and 33 on high-dose ICS (16 on budesonide, 17 on fluticasone propionate). Sputum from each subject underwent DNA extraction, amplification and 16S rRNA gene sequencing of the bacterial component of the microbiome. 19 subjects returned for further sputum induction after 24 h and 2 weeks.

RESULTS

A total of 5,615,037 sequencing reads revealed 167 bacterial taxa in the asthmatic airway samples, with the most abundant being Streptococcus spp. No significant differences in sputum bacterial load or overall community composition were seen between the low- and high-dose ICS groups. However, Streptococcus spp. showed significantly higher relative abundance in subjects taking low-dose ICS (p = 0.002). Haemophilus parainfluenzae was significantly more abundant in subjects on high-dose fluticasone propionate than those on high-dose budesonide (p = 0.047). There were no statistically significant changes in microbiota composition over a 2-week period.

DISCUSSION

Whilst no significant differences were observed between the low- and high-dose ICS groups, increased abundance of the potential pathogen H. parainfluenzae was observed in patients taking high-dose fluticasone propionate compared to those taking high-dose budesonide. The microbiota were stable over fourteen days, providing novel evidence of the established community of bacteria in the asthmatic airways.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT02671773.

Upper and lower airway inflammation in severe asthmatics: a guide for a precision biologic treatment

Background and aims:

Severe asthma may require the prescription of one of the biologic drugs currently available, using surrogate markers of airway inflammation (serum IgE levels and allergic sensitization for anti-IgE, or blood eosinophils for anti-IL5/IL5R). Our objective: to assess upper and lower airway inflammation in severe asthmatics divided according to the eligibility criteria for one of the target biologic treatments.

Methods:

We selected 91 severe asthmatics, uncontrolled despite high-dose ICS-LABA, and followed for >6 months with optimization of asthma treatment. Patients underwent clinical, functional and biological assessment, including induced sputum and nasal cytology. They were then clustered according to the eligibility criteria for omalizumab or mepolizumab/benralizumab.

Results:

Four clusters were selected: A (eligible for omalizumab, n = 23), AB (both omalizumab and mepolizumab, n = 26), B (mepolizumab, n = 22) and C (non-eligible for both omalizumab and mepolizumab, n = 20). There was no difference among clusters for asthma control (Asthma Control Test and Asthma Control Questionnaire 7), pre-bronchodilator forced expiratory volume in 1 s, serum IgE and fractional exhaled nitric oxide levels. Sputum eosinophils were numerically higher in clusters AB and B, in agreement with the higher levels of blood eosinophils. Allergic rhinitis was more frequent in clusters A and AB, while chronic rhinosinusitis with nasal polyps prevalence increased progressively from A to C. Eosinophils in nasal cytology were higher in clusters AB, B and C.

Conclusion:

Eosinophilic upper and lower airway inflammation is present in the large majority of severe asthmatics, independently from the prescription criteria for the currently available biologics, and might suggest the use of anti-IL5/IL5R or anti IL4/13 also in patients without blood eosinophilia.

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

Cough persistence in adults with chronic cough: A 4-year retrospective cohort study

BACKGROUND

There is very limited evidence regarding long-term prognosis of chronic cough. We examined longitudinal outcomes among patients with chronic cough, and explored predictors of cough persistence.

METHODS

A retrospective cohort was constructed of adults who had newly visited a specialist cough clinic in 2012-2013. All had undergone systematic investigation for chronic cough. The Hull Airway Reflux Questionnaire (HARQ) was administered to assess reflux cough symptoms. A follow-up survey was conducted in 2016-2017 to assess cough persistence.

RESULTS

From 418 candidates, 323 participated in the follow-up study; main analyses focused on patients with chronic persistent cough (n = 64; 19.8%) and remitted cough (n = 193; 59.8%). Compared with remitted cough group, chronic persistent cough group had more family history of chronic cough (17.2% vs. 4.7%, p = 0.001) and cold air-sensitive cough (62.5% vs. 44.6%, p = 0.013). The total HARQ score did not differ; however, two items (cough with eating and cough with certain foods) scored significantly higher in chronic persistent cough. In multivariate analyses, a family history of chronic cough (adjusted odds ratio 4.27 [95% confidence interval 1.35-9.89]), cold air-sensitive cough (2.01 [1.09-3.73]), and cough with eating (1.22 [1.02-1.45]) were associated with chronic persistent cough at 4 years.

CONCLUSIONS

Cough persists in about 20% of patients after 4 years following systematic assessment and treatments. Several cough characteristics, such as family history, cold air-sensitivity, or reflux cough, may be associated with cough persistence. Larger cohort studies are warranted to further understand long-term prognosis and confirm predictors of persistence in patients with chronic cough.

Rheological analysis of sputum from patients with chronic bronchial diseases

Bronchial diseases are characterised by the weak efficiency of mucus transport through the lower airways, leading in some cases to the muco-obstruction of bronchi. It has been hypothesised that this loss of clearance results from alterations in the mucus rheology, which are reflected in sputum samples collected from patients, making sputum rheology a possible biophysical marker of these diseases and their evolution. However, previous rheological studies have focused on quasi-static viscoelastic (linear storage and loss moduli) properties only, which are not representative of the mucus mobilisation within the respiratory tract. In this paper, we extend this approach further, by analysing both quasi-static and some dynamic (flow point) properties, to assess their usability and relative performance in characterising several chronic bronchial diseases (asthma, chronic obstructive pulmonary disease, and cystic fibrosis) and distinguishing them from healthy subjects. We demonstrate that pathologies influence substantially the linear and flow properties. Linear moduli are weakly condition-specific and even though the corresponding ranges overlap, distinct levels can be identified. This directly relates to the specific mucus structure in each case. In contrast, the flow point is found to strongly increase in muco-obstructive diseases, which may reflect the complete failure of mucociliary clearance causing episodic obstructions. These results suggest that the analysis of quasi-static and dynamic regimes in sputum rheology is in fact useful as these regimes provide complementary markers of chronic bronchial diseases.

TOB-STOP-COP (TOBacco STOP in COPd trial): study protocol-a randomized open-label, superiority, multicenter, two-arm intervention study of the effect of "high-intensity" vs. "low-intensity" smoking cessation intervention in active smokers with chronic obstructive pulmonary disease

BACKGROUND

Cigarette smoking is the leading cause of chronic obstructive pulmonary disease (COPD), and it contributes to the development of many other serious diseases. Smoking cessation in COPD patients is known to improve survival and reduce the number of hospitalization-requiring acute exacerbations of COPD. However, smoking cessation interventions in these patients have only been successful for approximately 15-20% for consistent smoking abstinence in 12 months. Thus, more effective interventions are needed for this patient group. The aim of this study is to determine whether a high-intensity intervention compared to a low-intensity intervention can increase the proportion of persistent (> 12 months) anamnestic and biochemical smoking cessation in active smokers with COPD.

METHODS

This study is a randomized controlled trial. A total of 600 active smokers with COPD will be randomly assigned 1:1 to either a standard treatment (guideline-based municipal smoking cessation program, "low intensity" group) or an intervention ("high-intensity" group) group, which consists of group sessions, telephone consultations, behavior design, hotline, and "buddy-matching" (smoker matched with COPD patient who has ceased smoking). Both groups will receive pharmacological smoking cessation. The primary endpoint is anamnestic and biochemical (cotinine analysis in urine) validated smoking cessation after 12 months.

DISCUSSION

The potential benefit of this project is to improve smoking cessation rates and thereby reduce smoking-related exacerbations of COPD. In addition, the project can potentially benefit from increasing the quality of life and longevity of COPD patients and reducing the risk of other smoking-related diseases.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04088942 . Registered on 13 September 2019.

Airway hyperresponsiveness to mannitol improves in both type 2 high and type 2 low asthma after specialist management

OBJECTIVES

Type 2 low (T2-low) asthma is reported to respond less to anti-inflammatory treatment compared with Type 2 high (T2-high) asthma. Airway hyperresponsiveness (AHR) to mannitol, a marker of airway mast cell activation, may be indicative of response to treatment in patients with T2-low disease. We investigated whether AHR to mannitol improves in patients with T2-low asthma after specialist management.

METHODS

Patients with asthma or suspected asthma, referred to our specialist outpatient clinic, were enrolled consecutively and assessed with FeNO, asthma control, blood eosinophils, mannitol and methacholine tests and induced sputum. T2-low asthma was defined in patients with FeNO < 25ppb and sputum eosinophils < 3% and blood eosinophils < 300µl^-1 at inclusion. Patients with asthma and AHR to mannitol (PD15 ≤ 635 mg) were followed and reassessed after 12 months of specialist management.

RESULTS

Thirty-two patients (Females: 56%, age: 22 years (15-59)) were followed. Fourteen (44%) with T2-high and 18 (56%) with T2-low asthma. Baseline AHR to mannitol was comparable: G_mean PD15: 150 mg (95% CI 61-368) and 214 mg (95% CI 106-432) for T2-high and T2-low asthma respectively (P = 0.51). Both groups improved equally: G_mean PD15: 488 mg (95% CI 311-767) and 507 mg (95% CI 345-746); corresponding to a doubling-dose of: 3.00 (95% CI 1.58-5.74, P = 0.003) and 2.28 (95% CI 1.47-3.53, P = 0.001) respectively. There were no concomitant improvements in AHR to methacholine.

CONCLUSION

Patients with asthma and AHR to mannitol improve similarly in responsiveness to mannitol after 12 months of specialist management regardless of Type 2 inflammatory biomarker levels. Mechanisms driving AHR in T2-low asthma need to be further elucidated.

Sputum and serum autoantibody profiles and their clinical correlation patterns in COPD patients with and without eosinophilic airway inflammation

Background

Autoimmunity plays a role in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, the autoantibody responses and their clinical correlation patterns in COPD patients with and without airway eosinophilic inflammation are unknown. The aim of this study was to compare the autoantibody profiles and their clinical associations in stable COPD patients, stratified by airway inflammatory phenotypes.

Methods

Matched sputum and serum, obtained from 62 stable COPD patients and 14 age-matched controls, were assayed for the presence of IgG and IgM antibodies against 13 autoantigens using protein array. A sputum eosinophil count ≥3% was used as cut-off value to stratify COPD patients into eosinophilic and non-eosinophilic groups. Correlation network analysis was used to evaluate the correlation patterns among autoantibody and clinical variables in each group.

Results

There were no significant differences of clinical parameters and autoantibody levels between the two COPD groups. In non-eosinophilic COPD, sputum anti-CytochromeC_IgG and anti-Aggrecan_IgM were significantly higher than those in healthy controls, and prior exacerbation was positively associated with lung function and sputum anti-Collagen-IV_IgG. While in eosinophilic COPD, sputum/serum anti-heat shock protein (HSP)47_IgG, serum anti-HSP70_IgG and serum anti-Amyloid-beta_IgG were significantly lower than those in healthy controls, and no significant correlation between prior exacerbations and lung function was found. Differences were also observed in network hubs, with the network for non-eosinophilic COPD possessing 9 hubs comprising two lung function parameters and seven autoantibodies, compared with eosinophilic COPD possessing 12 hubs all comprising autoantibodies.

Conclusions

Autoantibody responses were heterogeneous and differentially correlated with the exacerbation risk and other clinical parameters in COPD patients of different inflammatory phenotypes. These findings provide useful insight into the need for personalized management for preventing COPD exacerbations.

Sputum Vitamin D Binding Protein (VDBP) GC1S/1S Genotype Predicts Airway Obstruction: A Prospective Study in Smokers with COPD

Introduction

The vitamin D binding protein (VDBP, also known as GC-globulin) and vitamin D deficiency have been associated with chronic obstructive pulmonary disease (COPD). rs7041 and rs4588 are two single nucleotide polymorphisms of the VDBP gene, including three common allelic variants (GC1S, GC1F and GC2). Previous studies primarily assessed the serum levels of vitamin D and VDBP in COPD. However, less is known regarding the impact of the local release of VDBP on COPD lung function. Thus, we examined the association of sputum and plasma VDBP with lung function at baseline and at four years, and examined potential genetic polymorphism interactions.

Methods

The baseline levels of sputum VDBP, plasma VDBP and plasma 25-OH vitamin D, as well as the GC rs4588 and rs7041 genotypes, were assessed in a 4-year Finnish follow-up cohort (n = 233) of non-smokers, and smokers with and without COPD. The associations between the VDBP levels and the longitudinal decline of lung function were further analysed.

Results

High frequencies of the haplotypes in rs7041/rs4588 were homozygous GC1S/1S (42.5%). Higher sputum VDBP levels in stage I and stage II COPD were observed only in carriers with GC1S/1S genotype when compared with non-smokers (p = 0.034 and p = 0.002, respectively). Genotype multivariate regression analysis indicated that the baseline sputum VDBP and FEV1/FVC ratio at baseline independently predicted FEV1% at follow-up.

Discussion and Conclusion

The baseline sputum VDBP expression was elevated in smokers with COPD among individuals with the GC1S/1S genotype, and predicted follow-up airway obstruction. Our results suggest that the GC polymorphism should be considered when exploring the potential of VDBP as a biomarker for COPD.

Relationship between airway inflammation and airflow limitation in elderly asthmatics

Background

The prevalence of asthma in elderly population has been increasing. Previous studies have demonstrated clinical characteristics of elderly asthmatics (EA). However, little is known regarding the influence of immunological change on the physiological status of EA.

Objective

We investigated the relationship between inflammatory mediators and the pulmonary function (PF) of EA.

Methods

Eligible adult asthmatics recruited from the Allergy Center of Saitama Medical University Hospital were classified into a non-EA group (<40 years old, n = 15) and an EA group (≥60 years old, n = 43). Sputum induction and PF tests were performed. Concentrations of an eosinophil-derived neurotoxin (EDN) and neutrophil elastase (NE) in sputum supernatants were measured by enzyme-linked immunosorbent assay and a fluorometric assay using a commercial assay kit, respectively. Cell counts and EDN and NE concentrations in sputum were compared between the 2 groups. The association among those parameters and PF were analyzed in each group.

Results

The EA group had a significantly higher severe asthmatics proportion (p = 0.01), a lower current smokers proportion (p = 0.002), lower sensitization rate to aeroallergens (p = 0.012), several PFs deterioration (p < 0.0001) and lower total IgE levels (p = 0.001) than the non-EA group. Sputum neutrophil counts and NE concentrations were significantly higher in the EA group than those in the non-EA group (median neutrophil: 4.11 vs. 2.74 ×10⁵/mL, p = 0.03; NE: 2.0 vs.1.6 µg/mL, p < 0.05, respectively), whereas sputum eosinophil counts and EDN concentrations were not. Sputum EDN concentrations were significantly positively correlated with sputum neutrophil counts (r = 0.39, p = 0.031) and NE concentrations (r = 0.57, p < 0.0001) only in the EA group. Eosinophil-related parameters were negatively correlated with several PFs in the 2 groups. Neutrophil-related parameters were negatively correlated with PFs only in the non-EA group.

Conclusion

This study determines that in EA, persistent active eosinophilic airway inflammation is accompanied by advanced neutrophilic inflammation, which may contribute to deteriorated PF. This distinct airway inflammation may increase the severity of asthma in EA.

The clinical usefulness of a new hand-held device for fractional exhaled nitric oxide measurement, NIOX VERO®, for diagnosing the etiology of cough

Cough is one of the most common symptoms seen in clinical practice, however the differential diagnosis is often difficult. The utility of fractional exhaled nitric oxide (FeNO) measurement in the differential diagnosis of the etiology of cough has been reported. NIOX VERO® (NOV) is a new hand-held device that will replace NIOX MINO®, but its diagnostic utility has not been fully elucidated in clinical practice. In this study, the performance of NOV for FeNO measurements was determined. We retrospectively analyzed 243 consecutive patients complaining cough. Among 243 patients, final diagnosis was cough variant asthma (CVA) in 74 (30.5%), bronchial asthma (BA) in 48 (19.8%), post-infectious cough (PIC) in 52 (21.4%), atopic chough (AC) in 24 (9.9%), gastroesophageal reflux disease (GERD) in 10 (4.1%), and Others in 35 (14.4%). FeNO values were significantly higher in CVA and BA as compared to PIC, AC, GERD, and Others. In the multivariate analysis, only FeNO value was identified as independent factors to discriminate CVA and non-CVA other than BA. These findings indicated that FeNO measured by using NOV could be used as a diagnostic marker of intractable cough, especially for the differential diagnosis of CVA from non-CVA. J. Med. Invest. 67 : 265-270, August, 2020.

NMR-Based Metabolomics for the Assessment of Inhaled Pharmacotherapy in Chronic Obstructive Pulmonary Disease Patients

The aim of this proof-of-concept, pilot study was the evaluation of the effects of steroid administration and suspension of an inhaled corticosteroid (ICS)-long-acting β₂-agonist (LABA) extrafine fixed dose combination (FDC) on metabolomic fingerprints in subjects with chronic obstructive pulmonary disease (COPD). We hypothesized that a comprehensive metabolomics approach discriminates across inhaled pharmacotherapies and that their effects on metabolomic signatures depend on the biological fluids analyzed. We performed metabolomics via nuclear magnetic resonance (NMR) spectroscopy in exhaled breath condensate (EBC), sputum supernatants, serum, and urine. Fourteen patients suffering from COPD who were on regular inhaled fluticasone propionate/salmeterol therapy (visit 1) were consecutively treated with 2-week beclomethasone dipropionate/formoterol (visit 2), 4-week formoterol alone (visit 3), and 4-week beclomethasone/formoterol (visit 4). The comprehensive NMR-based metabolomics approach showed differences across all pharmacotherapies and that different biofluids provided orthogonal information. Serum formate was lower at visits 1 versus 3 (P = 0.03), EBC formate was higher at visit 1 versus 4 (P = 0.03), and urinary 1-methyl-nicotinamide was lower at 3 versus 4 visit (P = 0.002). NMR-based metabolomics of different biofluids distinguishes across inhaled pharmacotherapies, provides complementary information on the effects of an extrafine ICS/LABA FDC on metabolic fingerprints in COPD patients, and might be useful for elucidating the ICS mechanism of action.

Distinct profile of inflammatory and remodelling biomarkers in sputum of severe asthmatic patients with or without persistent airway obstruction

BACKGROUND

Both inflammatory and remodelling processes are associated with irreversible airway obstruction observed in severe asthma. Our aim was to characterize a group of severe asthmatic patients with or without persistent airway obstruction in relation to specific sputum inflammatory and remodelling biomarkers.

METHODS

Forty-five patients under regular high-dose inhaled corticosteroid/ß-2agonist treatment were studied, after a follow-up period of at least 2 years, with a minimum of 4 visits. Periostin, TGF-ß, RANTES, IL-8, GM-CSF, FGF-2, and cell counts were measured in induced sputum. Serum periostin was also measured.

RESULTS

Sputum induction was successfully performed in all but 5 patients. There were no significant differences in demographic and clinical data between patients with non-persistent obstruction (NO: FEV1/VC>88%pred.) and those with persistent obstruction (O: a not completely reversible obstruction with FEV1/VC<88%pred. at each visit before the study visit). Patients with persistent obstruction had significantly higher sputum periostin and TGF-ß concentrations than NO patients and a trend of higher serum periostin levels. GM-CSF and FGF-2 were significantly increased in NO compared to O patients. No differences between groups were found for RANTES, IL-8 and differential cell counts. Sputum periostin inversely correlated with functional parameters (prebronch. FEV1: rho = -0.36, p < 0.05; postbronch. FEV1: rho = -0.33, p = 0.05). Patients with high sputum periostin concentration (>103.3 pg/ml: median value) showed an absolute number of sputum eosinophils significantly higher than patients with low sputum periostin; this behavior was unobserved when serum periostin was considered.

CONCLUSIONS

Only periostin and TGF-ß identified a subgroup of severe asthmatic patients with persistent airway obstruction. Sputum periostin was also inversely associated with FEV1 and proved to be a more sensitive biomarker than serum periostin to identify severe asthmatics with higher sputum eosinophilia.

Colonization by Pneumocystis jirovecii in patients with chronic obstructive pulmonary disease: association with exacerbations and lung function status

Exposure to Pneumocystis jirovecii (P. jirovecii) can lead to a wide variety of presenting features ranging from colonization in immunocompetent patients with lung disease, to invasive infections in immunocompromised hosts. Colonization by this fungus in patients with chronic obstructive pulmonary disease (COPD) could be associated with higher rates of exacerbations and impaired lung function in these patients.

Our objective was to determine whether colonization by P. jirovecii in patients with COPD is associated with increased exacerbations and deterioration of lung function.

This was a prospective cohort study on patients with COPD. All participants meeting selection criteria underwent clinical and microbiological assessments and were then classified as colonized vs. non-colonized patients. Chi-squared tests were performed and multivariate logistic models were fitted in order to obtain risk ratios (RR) with 95% confidence intervals (CI).

We documented a frequency of colonization by P. jirovecii of 32.3%. Most patients were categorized as having GOLD B and D COPD. The history of significant exacerbations in the last year, health status impairment (COPD Assesment Tool ≥10), airflow limitation (percent of post-bronchodilator FEV1), and BODEx score (≥5) were similar between groups. After a 52-week follow-up period, the rate of adjusted significant exacerbations did not differ between groups. However, a decrease in FEVI was found in both groups.

Arachidonic Acid and Docosahexaenoic Acid Metabolites in the Airways of Adults With Cystic Fibrosis: Effect of Docosahexaenoic Acid Supplementation

Cystic fibrosis (CF) is an autosomal recessive disorder, caused by genetic mutations in CF transmembrane conductance regulator protein. Several reports have indicated the presence of specific fatty acid alterations in CF patients, most notably decreased levels of plasmatic and tissue docosahexaenoic acid (DHA), the precursor of specialized pro-resolving mediators. We hypothesized that DHA supplementation could restore the production of DHA-derived products and possibly contribute to a better control of the chronic pulmonary inflammation observed in CF subjects. Sputum samples from 15 CF and 10 chronic obstructive pulmonary disease (COPD) subjects were collected and analyzed by LC/MS/MS, and blood fatty acid were profiled by gas chromatography upon lipid extraction and transmethylation. Interestingly, CF subjects showed increased concentrations of leukotriene B₄ (LTB₄), prostaglandin E₂ (PGE₂), and 15-hydroxyeicosatetraenoic acid (15-HETE), when compared with COPD patients, whereas the concentrations of DHA metabolites did not differ between the two groups. After DHA supplementation, not only DHA/arachidonic acid (AA) ratio and highly unsaturated fatty acid index were significantly increased in the subjects completing the study (p < 0.05) but also a reduction in LTB₄ and 15-HETE was observed, together with a tendency for a decrease in PGE_2, and an increase in 17-hydroxy-docosahexaenoic acid (17OH-DHA) levels. At the end of the washout period, LTB₄, PGE₂, 15-HETE, and 17OH-DHA showed a trend to return to baseline values. In addition, 15-HETE/17OH-DHA ratio in the same sample significantly decreased after DHA supplementation (p < 0.01) when compared with baseline. In conclusion, our results show here that in CF patients, an impairment in fatty acid metabolism, characterized by increased AA-derived metabolites and decreased DHA-derived metabolites, could be partially corrected by DHA supplementation.

Biomass smoke COPD has less tomographic abnormalities but worse hypoxemia compared with tobacco COPD

Special attention has emerged towards biomass smoke-induced chronic obstructive pulmonary disease (COPD), providing new knowledge for prevention and therapeutic approach of non-smoker COPD patients. However, the understanding of biomass smoke COPD is still limited and somewhat controversial. The aim of the present study was to compare COPD exclusively caused by tobacco smoking with COPD exclusively caused by environmental or occupational exposures. For this cross-sectional study, COPD patients were recruited from outpatient clinics and formed two groups: non-smoker COPD group (n=16) with exposure to biomass smoke who did not smoke cigarette and tobacco smoker COPD group (n=15) with people who did not report biomass smoke exposure. Subjects underwent pulmonary function tests, thoracic high-resolution computed tomography, 6-min walk test, and sputum induction. The non-smoker COPD group had biomass smoke exposure of 133.3±86 hour-years. The tobacco COPD group smoked 48.5±27.4 pack-years. Women were 62.5 and 66.7%, respectively, of non-smokers and smokers. The non-smoker COPD group showed higher prevalence of dyspnea, lower arterial oxygen tension (PaO2), and lower arterial oxygen saturation (SaO2%) with similar spirometry results, lung volumes, and diffusion capacity. Regarding inflammatory biomarkers, differences were detected in sputum number of lymphomononuclear cells and in sputum concentrations of interleukin (IL)-6 and IL-8 with higher values in the smoker group. Emphysema was more prevalent in the tobacco smoker group, which also showed higher relative bronchial wall thickness and lower lung density by quantitative analysis. Biomass smoke induced more hypoxemia compared to tobacco in COPD patients with similar severity.

Implications of prostaglandin D2 and leukotrienes in exhaled breath condensates of asthma

BACKGROUND

Various inflammatory eicosanoid levels in biomaterials from airways of asthma and their associations with clinical parameters remain uncertain. We hypothesized that prostaglandin and leukotriene levels differ between in exhaled breath condensates (EBCs) and in sputum in mild, moderate, and severe levels of asthma and that EBC and sputum eicosanoid levels are associated with indexes of pulmonary function and inflammation.

OBJECTIVE

To determine the differences between EBC and sputum eicosanoid levels in healthy participants and patients with asthma with different asthma severity levels.

METHODS

Collected EBC and sputum, as well as pulmonary function, were examined in adult patients with asthma and healthy participants. Exhaled breath condensate prostaglandin D2-methoxime (PGD2-MOX), cysteinyl leukotrienes (CysLTs), leukotriene B4 (LTB4), and thromboxane B2 levels, and some sputum eicosanoid and tryptase levels were measured. Differences in eicosanoid levels among participants and their associations with pulmonary function and tryptase and granulocyte levels in sputum were then evaluated.

RESULTS

Analysis of 94 EBCs and 43 sputa revealed that EBC and sputum PGD2-MOX and CysLT levels were significantly higher in patients with asthma than in healthy participants. Exhaled breath condensate PGD2-MOX, CysLT, and LTB4 levels were significantly higher in patients with severe asthma. Exhaled breath condensate PGD2-MOX level was also significantly correlated with sputum tryptase levels and lower pulmonary function in patients with asthma. Sputum PGD2-MOX and CysLT levels were significantly correlated with the proportion of eosinophils among all cells in sputum in patients with asthma.

CONCLUSION

The results suggest that EBC PGD2 levels are associated with impairment of pulmonary function in adults with asthma who have undergone guideline treatment. Exhaled breath condensate or sputum PGD2 and CysLTs may represent severity or airway inflammation in asthma.

Induced Sputum as a Diagnostic Tool in Pneumonia in Under Five Children-A Hospital-based Study

OBJECTIVE

The objective of this articlewas to study the success, tolerability of sputum induction and the bacterial isolates of induced sputum in children aged <5 years.

METHODS

The cross-sectional study included 120 hospitalized children aged 1-59 months meeting WHO criteria for pneumonia. Sputum induction was performed using hypertonic (3%) saline.

RESULTS

Mean age of the subjects was 19.5 months (2-59 months). Overall success of sputum induction was 53.3% and highest (64.28%) in 37-59 months age group. Adverse events such as tachypnea, hypoxemia (SpO2 <90) and vomiting were observed in 41.6, 17.5 and 15.8%, respectively. A potential pathogen was isolated in 45 (70.3%) of 64 cases with good quality sputum. Klebsiella pneumoniae was the commonest (38.2%) followed by Streptococcus pneumoniae (14.8%) and others.

CONCLUSION

Sputum induction in young children is safe and feasible in Indian settings. While the success was limited, bacterial yield was high.

Physical activity associates with disease characteristics of severe asthma, bronchiectasis and COPD

BACKGROUND AND OBJECTIVE

Physical activity (PA) in obstructive airway diseases (OAD) is likely to be impaired but this has not been extensively studied outside of chronic obstructive pulmonary disease (COPD). We describe PA levels in severe asthma and bronchiectasis compared to moderate-severe COPD and to controls, and tested the cross-sectional associations of PA (steps/day) with shared disease characteristics in the OAD group.

METHODS

Adults with OAD (severe asthma = 62, COPD = 67, bronchiectasis = 60) and controls (n = 63) underwent a multidimensional assessment, including device-measured PA levels.

RESULTS

The OAD group included 189 participants (58.7% females), with median (interquartile range) age of 67 (58-72) years and mean forced expiratory volume in the first second (FEV₁ ) % predicted of 69.4%. Demographic characteristics differed between groups. Compared to controls (52.4% females, aged 55 (34-64) years, median 7640 steps/day), those with severe asthma, bronchiectasis and COPD accumulated less steps/day: median difference of -2255, -2289, and -4782, respectively (P ≤ 0.001). Compared to COPD, severe asthma and bronchiectasis participants accumulated more steps/day: median difference of 2375 and 2341, respectively (P ≤ 0.001). No significant differences were found between the severe asthma and bronchiectasis group. Exercise capacity, FEV₁ % predicted, dyspnoea and systemic inflammation differed between groups, but were each significantly associated with steps/day in OAD. In the multivariable model adjusted for all disease characteristics, exercise capacity and FEV₁ % predicted remained significantly associated.

CONCLUSION

PA impairment is common in OAD. The activity level was associated with shared characteristics of these diseases. Interventions to improve PA should be multifactorial and consider the level of impairment and the associated characteristics.

Increased Sputum IL-17A Level in Non-asthmatic Eosinophilic Bronchitis

BACKGROUND

Non-asthmatic eosinophilic bronchitis (NAEB) is one common cause of chronic cough which is characterized as airway eosinophilic inflammation like asthma but lack of airway hyper-responsiveness. Previous studies showed that Th2-pathway plays a role in NAEB, but the role of non-Th2 pathway in mechanism of NAEB remains unknown. Recently, IL-17A, a Th17-pathway cytokine, has been demonstrated to be involved in asthma development. However, the relationship between Th17-pathway and NAEB is unknown.

METHODS

We aim to assess the airway level of IL-17A in the subjects with NAEB. Relationships between the IL-17A level and airway function in NAEB or asthma are also observed. We measured IL-17A concentrations in the sputum supernatant from 12 subjects with EB, 16 subjects with asthma [9 eosinophilic asthmatic (EA) and 7 non-eosinophilic asthmatic (NEA) according to the sputum eosinophil ≥ 3%], and 9 healthy control subjects.

RESULTS

Increasing IL-17A level was found in NAEB group (29.65 ± 8.13 pg/ml), EA group (32.45 ± 3.22 pg/ml), and NEA group (29.62 ± 6.91 pg/ml) compared with the healthy control group (17.05 ± 10.30 pg/ml) (P < 0.05, P < 0.01, P < 0.05, respectively). The sputum IL-17A level was correlated with FENO (r = 0.44, P < 0.01), FEV1/FVC% (r = - 0.38, P < 0.05), MMEF%pred (r = - 0.34, P < 0.05), and sputum neutrophil% (r = 0.33, P < 0.05) in total.

CONCLUSION

Th17-pathway may play a role not only in asthmatics, but also in subjects with NAEB, as reflected by increasing IL-17A concentrations in sputum supernatant.

Lipid phenotyping of lung epithelial lining fluid in healthy human volunteers

BACKGROUND

Lung epithelial lining fluid (ELF)-sampled through sputum induction-is a medium rich in cells, proteins and lipids. However, despite its key role in maintaining lung function, homeostasis and defences, the composition and biology of ELF, especially in respect of lipids, remain incompletely understood.

OBJECTIVES

To characterise the induced sputum lipidome of healthy adult individuals, and to examine associations between different ELF lipid phenotypes and the demographic characteristics within the study cohort.

METHODS

Induced sputum samples were obtained from 41 healthy non-smoking adults, and their lipid compositions analysed using a combination of untargeted shotgun and liquid chromatography mass spectrometry methods. Topological data analysis (TDA) was used to group subjects with comparable sputum lipidomes in order to identify distinct ELF phenotypes.

RESULTS

The induced sputum lipidome was diverse, comprising a range of different molecular classes, including at least 75 glycerophospholipids, 13 sphingolipids, 5 sterol lipids and 12 neutral glycerolipids. TDA identified two distinct phenotypes differentiated by a higher total lipid content and specific enrichments of diacyl-glycerophosphocholines, -inositols and -glycerols in one group, with enrichments of sterols, glycolipids and sphingolipids in the other. Subjects presenting the lipid-rich ELF phenotype also had significantly higher BMI, but did not differ in respect of other demographic characteristics such as age or gender.

CONCLUSIONS

We provide the first evidence that the ELF lipidome varies significantly between healthy individuals and propose that such differences are related to weight status, highlighting the potential impact of (over)nutrition on lung lipid metabolism.

Understanding asthma phenotypes: the World Asthma Phenotypes (WASP) international collaboration

The World Asthma Phenotypes (WASP) study started in 2016 and has been conducted in five centres, in the UK, New Zealand, Brazil, Ecuador and Uganda. The objectives of this study are to combine detailed biomarker and clinical information in order to 1) better understand and characterise asthma phenotypes in high-income countries (HICs) and low and middle-income countries (LMICs), and in high and low prevalence centres; 2) compare phenotype characteristics, including clinical severity; 3) assess the risk factors for each phenotype; and 4) assess how the distribution of phenotypes differs between high prevalence and low prevalence centres. Here we present the rationale and protocol for the WASP study to enable other centres around the world to carry out similar analyses using a standardised protocol. Large collaborative and integrative studies like this are essential to further our understanding of asthma phenotypes. The findings of this study will help elucidate the aetiological mechanisms of asthma and might potentially identify new causes and guide the development of new treatments, thereby enabling better management and prevention of asthma in both HICs and LMICs.

Breathomics for Assessing the Effects of Treatment and Withdrawal With Inhaled Beclomethasone/Formoterol in Patients With COPD

Background: Prospective pharmacological studies on breathomics profiles in COPD patients have not been previously reported. We assessed the effects of treatment and withdrawal of an extrafine inhaled corticosteroid (ICS)-long-acting β₂-agonist (LABA) fixed dose combination (FDC) using a multidimensional classification model including breathomics.

Methods: A pilot, proof-of-concept, pharmacological study was undertaken in 14 COPD patients on maintenance treatment with inhaled fluticasone propionate/salmeterol (500/50 μg b.i.d.) for at least 8 weeks (visit 1). Patients received 2-week treatment with inhaled beclomethasone dipropionate/formoterol (100/6 μg b.i.d.) (visit 2), 4-week treatment with formoterol alone (6 μg b.i.d.) (visit 3), and 4-week treatment with beclomethasone/formoterol (100/6 μg b.i.d.) (visit 4). Exhaled breath analysis with two e-noses, based on different technologies, and exhaled breath condensate (EBC) NMR-based metabolomics were performed. Sputum cell counts, sputum supernatant and EBC prostaglandin E₂ (PGE₂) and 15-F_2t-isoprostane, fraction of exhaled nitric oxide, and spirometry were measured.

Results: Compared with formoterol alone, EBC acetate and sputum PGE₂, reflecting airway inflammation, were reduced after 4-week beclomethasone/formoterol. Three independent breathomics techniques showed that extrafine beclomethasone/formoterol short-term treatment was associated with different breathprints compared with regular fluticasone propionate/salmeterol. Either ICS/LABA FDC vs. formoterol alone was associated with increased pre-bronchodilator FEF_25−75% and FEV₁/FVC (P = 0.008–0.029). The multidimensional model distinguished fluticasone propionate/salmeterol vs. beclomethasone/formoterol, fluticasone propionate/salmeterol vs. formoterol, and formoterol vs. beclomethasone/formoterol (accuracy > 70%, P < 0.01).

Conclusions: Breathomics could be used for assessing ICS treatment and withdrawal in COPD patients. Large, controlled, prospective pharmacological trials are required to clarify the biological implications of breathomics changes. EUDRACT number: 2012-001749-42.