Peripheral Airways Research Articles

Small airway dysfunction and obesity in asthmatic patients: a dangerous liaison?

Asthma is a chronic condition characterized by inflammation throughout the entire bronchial airways. Recent findings suggest that ventilation inhomogeneity and small airway dysfunction (SAD) play a particularly significant role in asthma development and clinical manifestations. Obesity is a considerable risk factor for asthma development and morbidity in children and adults. A growing body of evidence suggests that SAD is linked to more severe asthma and poor asthma control in obese patients. However, the knowledge about the relationship between peripheral airway compromise and obesity in asthma is limited, mainly because of the historical lack of access to non-invasive assessment methods for studying SAD. Conventional lung function measurements, like spirometry, cannot accurately assess small airway function. However, in recent years, new specialized tests available in outpatient settings have been found to distinguish SAD from large airway obstruction more accurately compared to spirometry. Therefore, understanding the degree of peripheral airway implication in the underlying pathology is critical for effective asthma control and therapeutic decisions. This review highlights recent findings on the impact of SAD on asthma patients who are obese. Additionally, it explores how new diagnostic methods, such as impulse oscillometry (IOS), may be used in outpatient settings to detect small airway impairment in obese asthma at an early stage, potentially leading to improved asthma treatment.

Multiple breath washout and oscillometry after allogenic HSCT: a scoping review.

Pulmonary chronic graft-versus-host disease (cGVHD) is a substantial cause of pulmonary morbidity and mortality post-haematopoietic stem cell transplantation (HSCT). Current spirometry-based monitoring strategies have significant limitations. Understanding the utility of novel peripheral airway function tests - multiple breath washout (MBW) and oscillometry - is critical in efforts to improve detection, facilitate earlier intervention and improve outcomes. In this scoping review, we identified 17 studies investigating MBW or oscillometry, or both, after allogenic HSCT. Despite small study numbers limiting the ability to draw firm conclusions, several themes were evident. Detectable peripheral airway abnormality in MBW occurred in a substantial proportion prior to HSCT. MBW indices post-HSCT were more frequently abnormal than spirometry when reporting group data and among those with extrapulmonary cGVHD and pulmonary cGVHD. Changes in MBW indices over time may be more indicative of pulmonary complications than absolute values at any given time point. Oscillometry indices were often normal at baseline, but more frequently abnormal in those who developed pulmonary cGVHD. Pooling currently available individual participant data across these studies may improve our ability to formally compare their respective sensitivity and specificity at specific time points and assess the trajectory of MBW and oscillometry indices over time.

Ventilation dynamics using a portable device coupled to the six-minute walk test in people with long-COVID syndrome: a preliminary study

ObjectiveTo investigated the dynamic ventilatory responses and their influence on functional exercise capacity in patients with long-COVID-19 syndrome (LCS).ResultsSixteen LCS patients were subjected to resting lung function (spirometry and respiratory oscillometry-RO) and cardiopulmonary performance to exercise (Spiropalm®-equipped six-minute walk test-6MWT and cardiopulmonary exercise test-CPX). At rest, spirometry showed a normal, restrictive and obstructive pattern in 87.5%, 6.25% and 6.25% of participants, respectively. At rest, RO showed increased resonance frequency, increased integrated low-frequency reactance and increased difference between resistance at 4–20 Hz (R4-R20) in 43.7%, 50%, and 31.2% of participants, respectively. The median of six-minute walking distance (DTC6) was 434 (386–478) m, which corresponds to a value of 83% (78–97%) of predicted. Dynamic hyperinflation (DH) and reduced breathing reserve (BR) were detected in 62.5% and 12.5% of participants, respectively. At CPX, the median peak oxygen uptake (VO2peak) was 19 (14–37) ml/kg/min. There was a significant correlation of 6MWD with both R4-R20 (rs=-0.499, P = 0.039) and VO2peak (rs=0.628, P = 0.009). Our results indicate that DH and low BR are contributors to poor exercise performance, which is associated with peripheral airway disease. These are promising results considering that they were achieved with simple, portable ventilatory and metabolic systems.

Clinical impact of obesity on oscillometry lung mechanics in adults with asthma

BackgroundIn the year 2035, projections have estimated that 5% of the Scottish population will be morbidly obese defined as a body mass index (BMI) greater than or equal to 40 kg/m2. Airway oscillometry is an effort-independent test akin to bronchial sonar which measures resistance and compliance. ObjectiveTo evaluate the impact of obesity on lung mechanics using oscillometry. MethodsClinical data for 188 patients with respiratory physician–diagnosed moderate-to-severe asthma were retrospectively collected and analyzed. ResultsObesity (BMI 30-39.9 kg/m2) and morbid obesity (BMI ≥ 40 kg/m2) were associated with a significantly worse heterogeneity of peripheral resistance between 5 Hz and 20 Hz and peripheral compliance as low-frequency reactance at 5 Hz and area under the reactance curve, as compared with normal weight (BMI 18.5-24.9 kg/m2). Cluster analysis incorporating oscillometry identified a patient cohort who was older, obese, and female with combined impairment of spirometry and oscillometry coupled with more frequent severe exacerbations. ConclusionObesity is associated with worse peripheral airway dysfunction in moderate-to-severe asthma, including a patient cluster who was older, obese, and female with more frequent exacerbations.

Sex-dependent influence of LMAN1 on lung function and allergen-induced airway hyperresponsiveness

Abstract We recently reported LMAN1 as a regulatory receptor capable of downregulating NF-kB signaling in response to house dust mite (HDM) in vitro. In this follow up work, we have subjected WT and LMAN1 KO mice to a HDM model of allergic airway inflammation and assessed lung function and airway hyperreactivity (AHR). Given our previous in vitro findings, we had expected worsened disease in the absence of LMAN1. Interestingly, when mice were stratified by sex, we observed that while female, HDM-treated LMAN1 KO mice exhibited signs of enhanced airway narrowing and closure and enhanced AHR compared to their WT counterparts, male, HDM-treated LMAN1 KO mice showed the opposite trend. These sex-dependent effects appeared to be localized to the peripheral airways. We additionally characterized the type and extent of immune cell infiltration into the airway and highlight those features which might account for the gender-biased effects of LMAN1 on lung function in the setting of allergic asthma.

Real-world effects of once-daily inhaled steroid (fluticasone furoate) combined with long-acting beta-2 agonist (vilanterol) and long-acting muscarinic antagonist (umeclidinium) on lung function tests of asthma patients in Japan.

Background: The Japanese drug use system allowed the once-daily use of inhaled corticosteroid fluticasone furoate (FF) combined with a long-acting beta-2 agonist vilanterol (VI) and a long-acting muscarinic antagonist umeclidinium (UMEC) against asthma on 18 February 2021. We investigated the real-world effects of these drugs (FF/UMEC/VI) mainly on lung function tests. Methods: This was an open-label, uncontrolled, within-group time-series (before-after) study. Prior asthma treatment (inhaled corticosteroid with/without a long-acting beta-2 agonist with/without a long-acting muscarinic antagonist) was switched to FF/UMEC/VI 200/62.5/25μg. Subjects were evaluated by lung function tests prior to, and 1-2months after, initiation of FF/UMEC/VI 200/62.5/25μg. Patients were asked questions regarding the asthma control test and preference for drugs. Results: Overall, 114 asthma outpatients (97% Japanese) were enrolled from February 2021 to April 2022: 104 subjects completed the study. Forced expiratory volume in 1s, peak flow, and asthma control test score of FF/UMEC/VI 200/62.5/25μg-treated subjects were significantly increased (p < 0.001, p < 0.001, and p < 0.01, respectively). In contrast with FF/VI 200/25μg, instantaneous flow at 25% of the forced vital capacity and expiratory reserve volume were significantly increased by FF/UMEC/VI 200/62.5/25μg (p < 0.01, p < 0.05, respectively). Sixty-six percent of subjects declared they wanted to continue FF/UMEC/VI 200/62.5/25μg in the future. Adverse effects, mainly local, were seen in 30% of patients, but no serious adverse effects were seen. Conclusion: Once-daily FF/UMEC/VI 200/62.5/25μg was effective against asthma without serious adverse events. This is the first report that demonstrated FF/UMEC/VI dilated peripheral airways using lung function tests. This evidence on drug effects may improve our understanding of pulmonary physiology and the pathophysiology of asthma.

Luteolin suppresses inflammation and oxidative stress in chronic obstructive pulmonary disease through inhibition of the NOX4‐mediated NF‐κB signaling pathway

Chronic obstructive pulmonary disease (COPD) is associated with chronic inflammation that predominantly affects the lung and peripheral airways. Previous investigation has underlined the efficacy of luteolin in the treatment of inflammation-related symptoms. Accordingly, our study concentrates on unveiling the effect of luteolin on COPD. Mice or A549 cells were treated with cigarette smoke (CS) to establish COPD models in vivo and in vitro. Then, the serum and bronchoalveolar lavage fluidof mice were harvested. The lung tissues of mice were subjected to hematoxylin-eosin staining to observe the degree of damage. The inflammation and oxidative stress factors level were calculated via enzyme-linked immunosorbent assay and quantitative real-time polymerase chain reaction. The expressions of nuclear factor-kappa B (NF-κB) pathway-related factors were detected by Western blot. In in vivo experiments, CS treatment reduced the weight of mice and promoted lung tissue damage, while luteolin attenuated the effect of CS on the mice. Moreover, luteolin inhibited the inflammation factors level, oxidative stress, and NADPH oxidase 4 (NOX4)-mediated NF-κB signaling pathway in CS-induced COPD mice. Similar results were obtained in in vitro experiments that luteolin alleviated CS-induced inflammation, oxidative stress, and NOX4-mediated NF-κB signaling pathway activation in CS-treated A549 cells. Besides, NOX4 overexpression offset the impacts of luteolin on the CS-induced A549 cells. Luteolin alleviates inflammation and oxidative stress in COPD via NOX4-mediated NF-κB signaling pathway, which provides a theoretical basis for the treatment of COPD with luteolin.

MR imaging of the airways.

The need for airway imaging is defined by the limited sensitivity of common clinical tests like spirometry, lung diffusion (DLCO) and blood gas analysis to early changes of peripheral airways and to inhomogeneous regional distribution of lung function deficits. Therefore, X-ray and computed tomography (CT) are frequently used to complement the standard tests.As an alternative, magnetic resonance imaging (MRI) offers radiation-free lung imaging, but at lower spatial resolution. Non-contrast enhanced MRI shows healthy airways down to the first subsegmental level/4th order (CT: eighth). Bronchiectasis can be identified by wall thickening and fluid accumulation. Smaller airways become visible, when altered by peribronchiolar inflammation or mucus retention (tree-in-bud sign).The strength of MRI is functional imaging. Dynamic, time-resolved MRI directly visualizes expiratory airway collapse down to the lobar level (CT: segmental level). Obstruction of even smaller airways becomes visible as air trapping on the expiratory scans. MRI with hyperpolarized noble gases (3He, 129Xe) directly shows the large airways and peripheral lung ventilation. Dynamic contrast-enhanced MRI (DCE MRI) indirectly shows airway dysfunction as perfusion deficits resulting from hypoxic vasoconstriction of the dependent lung volumes. Further promising scientific approaches such as non-contrast enhanced, ventilation-/perfusion-weighted MRI from periodic signal changes of respiration and blood flow are in development.In summary, MRI of the lungs and airways excels with its unique combination of morphologic and functional imaging capacities for research (e.g., in chronic obstructive lung disease or asthma) as well as for clinical imaging (e.g., in cystic fibrosis).

Airspace Dimension Assessment for early detection of lung function impairment in the peripheral airways of firefighters.

Firefighters have increased risk of chronic respiratory disease. Standard clinical techniques used in medical checkups may not detect the earliest microstructural changes in peripheral airways. A new technique called Airspace Dimension Assessment (AiDA) has been shown to enable early detection of emphysema in COPD. This method may be useful in the occupational setting to detect early pulmonary changes and enable prevention. The aim of the present study was to evaluate whether AiDA detects changes in the most peripheral airways of firefighters. AiDA, measuring the effective airspace radius (r AiDA) and zero-second recovery (R 0), was used as a complement to other standardised lung function measures in 21 male firefighters and 16 age-matched male controls. There were significant differences in r AiDA and R 0 between firefighters (mean±sd r AiDA 0.301±0.024 mm; mean±sd R 0 0.336±0.116 arbitrary units) and controls (mean±sd r AiDA 0.276±0.044 mm; mean±sd R 0 0.5760.168 arbitrary units), p=0.03 and p<0.001, respectively. Higher forced vital capacity was found in firefighters (mean 101% of predicted) than in controls (mean 93% of predicted; p=0.03). No significant differences were found with regard to either the ratio between forced expiratory volume in 1 s and forced vital capacity or forced expiratory volume in 1 s. The majority of firefighters had diffusing capacity of the lung for carbon monoxide, oscillometry and single-breath nitrogen washout values within the normal ranges. AiDA parameters can provide information on early pulmonary peripheral changes that may not be seen with standard techniques used in screening of pulmonary function.

Validation of the fractional exhaled breath temperature measurement: reference values

Exhaled breath temperature (EBT) is a known biomarker of inflammation and airways blood flow. As opposed to previous studies, we were able to measure temperature of separate fractions of exhaled breath (fEBT) (those from the peripheral and central airways). The aim was to validate the fEBT measurement method to determine the reference values and the influence of endogenous and exogenous factors on fEBT in healthy subjects. This cross-sectional study included 55 healthy adults in whom fEBT was repeatedly measured, two days in a row, using a FractAir® device. Also, basal metabolic rate, level of physical activity, distance from the main road, outdoor and ambient temperature, air pressure and humidity, haematology and inflammation markers, lung function, cumulative EBT and body temperature at characteristic points on the body were measured. The results showed that fEBT from central airways was lower compared to fEBT from the periphery and that fEBTs were not related to body temperature (p > 0.05 for all). We also showed repeatability of fEBT measurements for two consecutive days. All EBT fractions correlated significantly with ambient temperature (<0.01). No associations of fEBT with other personal and external factors were found using multivariate analysis. At room temperature of 22 °C, the physiological temperature values of the first fraction were 23.481 ± 3.150 °C, the second fraction 26.114 ± 4.024 °C and the third fraction 28.216 ± 3.321 °C. The proposed reference values represent the first part of validation of fEBT as the method for the use in clinical practice.

Lung Function in Children with Primary Ciliary Dyskinesia

Primary ciliary dyskinesia (PCD) is characterized by impaired mucociliary clearance that results in accumulation of mucus and bacteria in the airways. Lower respiratory tract infections lead to airway remodeling and lung function impairment. The aim of our narrative review is to discuss available data on lung function in PCD children, focusing on risk factors for lung function impairment. Relevant published studies searching MEDLINE/Pubmed are included in this narrative review, using these terms: "primary ciliary dyskinesia" and "pulmonary function test" or "spirometry" or "lung function". Filters were language (English) and age of study subjects (0-18 years). The majority of recent published studies showed normal spirometric values in PCD children, even if some authors described a pulmonary impairment. Together with spirometry, Lung Clearance Index has been applied for detecting peripheral airway disease, and it might have a role in early mild lung disease assessment. Studies on lung function trajectories after PCD diagnosis showed a significant heterogeneity, with some patients maintaining reasonably good lung function, whereas others showing a decline. Further studies are needed to analyze lung function prospectively from childhood into adulthood, and to evaluate whether lung function trajectories are affected by PCD clinical phenotype, ultrastructural ciliary defect or genetic background.

Early Life Risk Factors for Small Airways Dysfunction Across Childhood and Adolescence as Measured by Impulse Oscillometry

Early life risk-factors are important to lung health across the lifespan. Increased airway resistance (R) as assessed by R5-R20 Hz using Impulse Oscillometry (IOS) is a non-invasive assessment of peripheral airway dysfunction. We hypothesized that early life exposures and risk factors in participants in the Childhood Origins of ASThma (COAST) birth-cohort study will influence R5-R20 across childhood and adolescence.

In young children with asthma, obesity and uncontrolled disease are highly associated with peripheral airway impairment

BackgroundDespite the fact that impulse oscillometry (IOS)-determined peripheral airway impairment (PAI) phenotype is a major risk factor for uncontrolled asthma, IOS is seldom used clinically. ObjectiveTo identify clinical characteristics that can best identify the PAI phenotype. MethodsClinical characteristics and spirometry results were compared in 227 patients with asthma with the PAI phenotype determined by resistance and reactance values that exceeded IOS‑predictive normal values using Gochicoa-Rangel equations. Logistic regression analyses determined factors associated with PAI phenotype, with risk classification based on predicted probability from the final adjusted model. ResultsAnalysis for identifying PAI, present in 37% of our population, revealed statistically significant odds ratio (OR) for age (4-7 years), of 3.75 (1.47-9.55) (P = .006), obesity OR of 2.59 (1.36-4.96) (P = .004), uncontrolled asthma OR of 2.77 (1.34-5.74) (P = .006), and abnormal forced expiratory flow between 25% and 75% (FEF25%-75%) (<65%) OR of 4.22 (1.59-11.20) (P = .004). For identifying PAI in those considered well controlled, key characteristics were age (4-7 years), OR of 2.81 (1.10-7.18) (P = .03), and obesity, OR of 2.18 (1.09-4.39) (P = .03). For those 4 to 7 years old, who were obese and had uncontrolled disease, probability of PAI was greater than or equal to 80%, regardless of FEF 25%-75%. Probabilities from logistic regression analyses to identify PAI were associated with an area under the curve of 0.750, and applying standard threshold of greater than or equal to 0.50 probability for identification produced sensitivity at 49.4%, specificity at 85.3%, positive predictive value at 66.1%, negative predictive value at 74.4%, and accuracy at 72.1%. ConclusionClinical characteristics of age at 4 to 7 years, obesity, uncontrolled asthma, and FEF 25%-75% (<65%) identify PAI with high specificity and accuracy. This approach offers the clinician a practical method for strongly considering the presence of PAI when IOS is not available.

Impaired Respiratory System Resistance and Reactance Are Associated With Bronchial Wall Thickening in Persistent Asthma

A recent study demonstrated a significant correlation between bronchial biopsy airway remodelling with quantitative computed tomography looking at bronchial wall thickness. To identify clinical associations with bronchial wall thickness in moderate-to-severe asthma. 92 respiratory physician diagnosed GINA-defined moderate-to-severe asthma patients were included in this retrospective cohort study. Blinded to all clinical data, two senior thoracic radiologists independently measured airway lumen and total airway area at four different bronchopulmonary segments using high resolution CT imaging. We calculated adjusted odds ratios (aORs) in regard to the association of bronchial wall thickness with spirometry, oscillometry, exacerbations and nasal polyps. The pooled analysis for all four bronchopulmonary segments showed that AX≥1.0kPa/L, R5-R20 ratio ≥25%, ≥2 exac/yr and nasal polyposis exhibited aOR (95%CI) of 3.54 (1.22,10.32); 2.89 (1.03,8.05); 4.17 (1.25,13.90); and 9.85 (2.33,41.74) respectively in their association with wall area thickness ≥50%. These translated into a respective 72%, 65%, 76% and 90% increased likelihood for wall area ≥50%. Bronchial wall thickness is associated with peripheral airways resistance and reactance, severe exacerbations and nasal polyposis in persistent asthma.

TGF-β1 promotes SCD1 expression via the PI3K-Akt-mTOR-SREBP1 signaling pathway in lung fibroblasts

BackgroundLung fibroblast activation is associated with airway remodeling during asthma progression. Stearoyl-CoA desaturase 1 (SCD1) plays an important role in the response of fibroblasts to growth factors. This study aimed to explore the effects of SCD1 on fibroblast activation induced by transforming growth factor-β1 (TGF-β1) and the role of the phosphatidylinositol-3-kinase-AKT serine-threonine protein kinase-mechanistic target of rapamycin (PI3K-Akt-mTOR) pathway on the regulation of SCD1 expression in airway remodeling.MethodsFemale C57BL/6 mice were sensitized and challenged with house dust mites to generate a chronic asthma model. The inhibitor of SCD1 was injected i.g. before each challenge. The airway hyper-responsiveness to methacholine was evaluated, and airway remodeling and airway inflammation were assessed by histology. The effects of SCD1 on fibroblast activation were evaluated in vitro using an SCD1 inhibitor and oleic acid and via the knockdown of SCD1. The involvement of the PI3K-Akt-mTOR-sterol regulatory element-binding protein 1 (SREBP1) pathway in lung fibroblasts was investigated using relevant inhibitors.ResultsThe expression of SCD1 was increased in fibroblasts exposed to TGF-β1. The inhibition of SCD1 markedly ameliorated airway remodeling and lung fibroblast activation in peripheral airways. The knockdown or inhibition of SCD1 resulted in significantly reduced extracellular matrix production in TGF-β1-treated fibroblasts, but this effect was reversed by the addition of exogenous oleic acid. The PI3K-Akt-mTOR-SREBP1 pathway was found to be involved in the regulation of SCD1 expression and lung fibroblast activation.ConclusionsThe data obtained in this study indicate that SCD1 expression contributes to fibroblast activation and airway remodeling and that the inhibition of SCD1 may be a therapeutic strategy for airway remodeling in asthma.

Peripheral Airway Dysfunction in Obesity and Obese Asthma

The purpose of this study was to investigate physiological phenotypes of asthma in obesity. Do physiological responses during bronchoconstriction distinguish different groups of asthma in people with obesity, and also differentiate from responses simply related to obesity? Cross-sectional study of people with obesity (31 with asthma and 22 without lung disease). Participants underwent methacholine challenge testing with measurement of spirometry and respiratory system impedance by oscillometry. Participants had class III obesity (BMI, 46.7 ± 6.6kg/m2 in control subjects and 47.2 ± 8.2kg/m2 in people with asthma). Most participants had significant changes in peripheral airway impedance in response to methacholine: in control subjects, resistance at 5Hz measured by oscillometry increased by 45%± 27%and area under the reactance curve (AX) by 268%± 236%in response to 16mg/mL methacholine; in people with asthma, resistance at 5Hz measured by oscillometry increased by 52%± 38%and AX by 361%± 295%in response to provocation concentration producing a 20% fall in FEV1 dose of methacholine. These responses suggest that obesity predisposes to peripheral airway reactivity. Two distinct groups of asthma emerged based on respiratory system impedance: one with lower reactance (baseline AX, 11.8; interquartile range, 9.9-23.4cm H2O/L) and more concordant bronchoconstriction in central and peripheral airways; the other with high reactance (baseline AX, 46.7; interquartile range, 23.2-53.7cm H2O/L) and discordant bronchoconstriction responses in central and peripheral airways. The high reactance asthma group included only women, and reported significantly more gastroesophageal reflux disease, worse chest tightness, more wheeze, and more asthma exacerbations than the low reactance group. Peripheral airway reactivity detected by oscillometry is common in obese control subjects and obese people with asthma. There is a subgroup of obese asthma characterized by significant peripheral airway dysfunction by oscillometry out of proportion to spirometric airway dysfunction. This peripheral dysfunction represents clinically significant respiratory disease not readily assessed by spirometry.

Fractional nitric oxide measurement in exhaled air (FeNO): perspectives in the management of respiratory diseases.

Exhaled nitric oxide (NO) production, upregulated by inflammatory cytokines and mediators in central and peripheral airways, can be easily and non-invasively detected in exhaled air in asthma and other respiratory conditions as a promising tool for disease monitoring. The American Thoracic Society and European Respiratory Society released recommendations that standardize the measurement of the fractional exhaled NO (FeNO). In asthma, increased FeNO reflects eosinophilic-mediated inflammatory pathways and, as a biomarker of T2 inflammation can be used to identify asthma T2 phenotype. In this setting its measurement has shown to be an important tool especially in the diagnostic process, in the assessment and evaluation of poor adherence or predicting positive response to inhaled corticosteroids treatment, in phenotyping severe asthma patients and as a biomarker to predict the response to biologic treatments. The discovery of the role of NO in the pathogenesis of different diseases affecting the airways and the possibility to estimate the predominant site of increased NO production has provided new insight on its regulatory role in the airways, making it suitable for a potential extended use in clinical practice for different pulmonary diseases, even though its role remains less clear than in asthma. Monitoring FeNO in pulmonary obstructive lung diseases including chronic bronchitis and emphysema, interstitial lung diseases, obstructive sleep apnea and other pulmonary diseases is still under debate but has opened up a window to the role NO may play in the management of these diseases. The use of FeNO is reliable, cost effective and recommendable in both adults and children, and should be implemented in the management of patients with asthma and other respiratory conditions.

Дисфункція дрібних дихальних шляхів та можливості її корекції при астмі

Abstract. Background. Although randomized controlled trials have shown that asthma control is an achievable goal, real-life studies over the past 20 years have shown that asthma remains poorly controlled in a significant proportion of patients, even among those receiving treatment at asthma specialist, and in patients with mild asthma who regularly take inhaled corticosteroids. Even when asthma control is achieved, it is not optimal on all GINA steps. The small airways have been recognized as the primary site of airflow limitation in asthma. The aim of the work: to study, according to the literature, the peculiarities of the dysfunction of the small airways in asthma and to evaluate the possibilities of its treatment. Materials and methods. Scientific articles that covered the pathophysiology of small airways disorders, their impact on asthma control, diagnostic methods, and pharmacological treatment methods were analyzed. The results. Airways with an internal diameter &lt; 2 mm, which do not contain cartilage in their walls and extend from the 8th generation of the airways to the periphery of the lung, are collectively called “small airways”. They are called the QUIET ZONE because they are difficult to assess and treat in patients with asthma who are not optimally controlled but have relatively normal FEV1 and disproportionate small airways dysfunction (SAD). Predominant in patients at all stages of treatment, associated with poor disease control. The ATLANTIS study showed that up to 91 % of patients with asthma have. The small airways have a high density of corticosteroid and β2-adrenoceptors, which means that they can be influenced. The main task is that the drugs should reach these small airways. Conventional inhalers that generate particles larger than 2 μm do not address the problem of SAD in patients with asthma. Inhaler devices that produce ultrafine particles of inhaled corticosteroids alone or in combination with long-acting β-agonists with a diameter of less than 2 μm have the potential to improve long-term asthma control along with a corresponding improvement in small airway function. The fixed combination of beclomethasone dipropionate with formoterol has optimal deposition in the respiratory tract — central pulmonary deposition accounts for 66 %, and peripheral — 34 % of the dose, thus the drug is delivered to both the central and peripheral respiratory tracts and affects inflammation and bronchoconstriction throughout the lungs. This is facilitated by MODULITE technology. The effectiveness and safety of the use of the BDP/F combination (Foster) in MART regimen is confirmed by a significant evidence base, which guaranteed its place in the Track1 treatment of asthma. Conclusions: Patients with asthma have a serious inflammatory process in the peripheral airways, which makes them the main site of obstruction in asthma; SAD predominates in patients at all stages of asthma, is associated with poor disease control, is responsible for air trapping, correlates with poor asthma control1, and predicts an increased risk of exacerbations in patients. The fixed combination of beclamethasone/formoterol in one inhaler (Foster) is the only extrafinely dispersed fixed combination of ICS/LABA that reaches the small airways; the fixed combination of BDP/Formoterol in the MART regimen provides a significant reduction in the frequency of severe complications, hospitalizations, emergency calls, and reduces the number of courses of systemic corticosteroids.

The HDAC10 instructs macrophage M2 program via deacetylation of STAT3 and promotes allergic airway inflammation.

Background: Perturbation of macrophage homeostasis is one of the key mechanisms of airway inflammation in asthma. However, the exact mechanisms remain poorly understood. Objectives: We sought to examine the role of histone deacetylase (HDAC) 10 as an epigenetic regulator that governs macrophage M2 program and promotes airway inflammation in asthma, and to elucidate the underlying mechanisms. Methods: Peripheral blood and airway biopsies were obtained from healthy individuals and asthmatic patients. Asthma was induced by exposure to allergen in mice with myeloid-specific deletion of Hdac10 (Hdac10fl/fl-LysMCre) mice. HDAC10 inhibitor Salvianolic acid B (SAB), STAT3 selective agonist Colivelin, and the specific PI3K/Akt activator 1,3-Dicaffeoylquinic acid (DA) were also used in asthmatic mice. For cell studies, THP1 cells, primary mouse bone marrow derived macrophage (BMDMs) were used and related signaling pathways was investigated. Results: HDAC10 expression was highly expressed by macrophages and promoted M2 macrophage activation and airway inflammation in asthmatic patients and mice. Hdac10fl/fl-LysMCre mice were protected from airway inflammation in experimental asthma model. Hdac10 deficiency significantly attenuated STAT3 expression and decreased M2 macrophage polarization following allergen exposure. Mechanistically, HDAC10 directly binds STAT3 for deacetylation in macrophages, by which it promotes STAT3 expression and activates the macrophage M2 program. Importantly, we identified SAB as a HDAC10 inhibitor that had protective effects against airway inflammation in mice. Conclusions: Our results revealed that HDAC10-STAT3 interaction governs macrophage polarization to promote airway inflammation in asthma, implicating HDAC10 as a therapeutic target.

Research of the diagnostic utility of impulse oscillometry in patients with bronchiectasis

Background: Bronchiectasis is a chronic respiratory condition in which infection, inflammation, and damage of the airways all play a role. Intense airway inflammation is precipitated by pathogenic insults, resulting in chronic airway damage. Impulse oscillometry (IOS) is a noninvasive approach that might offer worldwide information on airway resistance by researching the mechanical waves superimposed upon breathing movements. It has been observed that IOS may differentiate peripheral airways abnormalities in chronic obstructive pulmonary disease (COPD), asthma, interstitial pulmonary disease (ILD) and pulmonary fibrosis (CF) with high degree of precision. Methods: This research was carried out on 40 cases with bronchiectasis diagnosed by HRCT. Such cases were classified into two groups, according to Bronchiectasis Severity Index (BSI)(108): group I: Included 20 cases with mild to moderate bronchiectasis and group II: Included 20 cases with severe bronchiectasis. Cases included in the research were subjected to full history taking and complete physical examination. This includes: Complete blood count (CBC), sputum culture, chest x-ray to exclude cases with other lung diseases, High-Resolution Computerized Tomography (HRCT), that were interpreted for the presence, pattern and distribution of bronchiectasis, arterial blood gases, echocardiography, measuring systolic pulmonary artery pressure, pulmonary function tests (PFT), Impulse Oscillometry and reactance area (AX) were measured. Results: Regarding disease duration, no significant differences was found between both groups while a statistically significant difference was observed between groups regarding the used medications. Regarding laboratory investigations, no significant difference was observed among the groups for any of the measured measurements. Regarding functional assessment data, A statistically evident difference was found between groups in the following: MEF 50%, FEV1% predicted, FEV1/FVC% and FVC% with no significant differences in FEV1. Regarding IOS measurements, A statistically evident difference was found between both groups in R5% predicted while no difference was observed regarding R5 actual, R20, AX, or X5. Positive correlation was very high in between HRCT score and each of FEV1% predicted, FVC (%) AX, R5% predicted, R5 actual, R20 and X5 but negative correlation was very high in between HRCT score and MEF 75%, FEV1/FVC% Conclusions: IOS measurements are markedly increased in cases with bronchiectasis and they are correlated with spirometric measurements and HRCT scores.