Persistent Airway Research Articles

Role of serum periostin as a biomarker in diagnosis of bronchial asthma

Background Asthma is a chronic airway disease that is characterized by persistant airway inflammation and remoldeing with bronchial hyperactivity in resulted from one allergen or more leading to episodic airflow obstruction. Periostin can be detected in serum of asthmapatients which largly reflected to its level production in airway. Periostin is secreted by airway epithlialcellin response to iL-13 stimulation and easly leak into the airway capillary. Serum periostin could be aperdector ofairway esinophilliato patients with severeasthma. Aim of the work Is estimating the serum periostin level in patients with bronchial asthma to evaluate its role in diagnosis. Methodology This study was carried out on 25 normal healthy individual serveing as control (Group I), 25 patients diagnosed as atopic asthmatic patient regarding to skin prick test (its postive>3) (Group II) and 25 patients diagnosed as non-atopic asthmatic patient regarding to skin prick test (its negative Results Statistical analysis of the results of present work showed that serum periostin was significantly higher in asthmatic group (atopic and non atopic) in comparison to control group. Serum perioestin was also significantly higher in group 11 (atopic asthma) than group 111 (non atopic asthma) as cutting off was>420 and sensitivity and specifity was 40.0, 100.0 resepctivily. Conclusion Serum periostin can be used in dignosis of asthma and differntiation of atopic asthma from non atopic asthma.

Der f1 induces pyroptosis in human bronchial epithelia via the NLRP3 inflammasome.

Damage to the bronchial epithelium leads to persistent inflammation and airway remodelling in various respiratory diseases, such as asthma and chronic obstructive pulmonary disease. To date, the mechanisms underlying bronchial epithelial cell damage and death by common allergens remain largely unknown. The aim of the present study was to investigate Der f1, an allergen of Dermatophagoides farinae, which may result in the death of human bronchial epithelial cells (HBECs). Der f1 induces BECs to undergo the inflammatory cell death referred to as pyroptosis, induced by increasing lactate dehydrogenase release and propidium iodide penetration. Stimulation by Der f1 enhances interleukin (IL)-1β cleavage and release, which is associated with caspase-1 activation. In addition, the NOD-like receptor family pyrin domain-containing 3 (NLRP3), is required for the activation of caspase-1 through increasing the formation of the inflammasome complex. Consistent with these findings, pre-treatment of HBECs with a caspase-1 inhibitor, or silencing of NLRP3 by siRNA transfection, reduced Der f1-mediated IL-1β and pyroptosis. Therefore, the common allergen Der f1 was not only found to induce allergy, but also led to pyroptosis and IL-1β secretion via the NLRP3-caspase-1 inflammasome in HBECs. This newly identified connection of the Der f1 allergen with BEC damage and inflammation may play an important role in the pathogenesis of asthma.

Human Parvovirus Infection of Human Airway Epithelia Induces Pyroptotic Cell Death by Inhibiting Apoptosis.

Human bocavirus 1 (HBoV1) is a human parvovirus that causes acute respiratory tract infections in young children. In this study, we confirmed that, when polarized/well-differentiated human airway epithelia are infected with HBoV1 in vitro, they develop damage characterized by barrier function disruption and cell hypotrophy. Cell death mechanism analyses indicated that the infection induced pyroptotic cell death characterized by caspase-1 activation. Unlike infections with other parvoviruses, HBoV1 infection did not activate the apoptotic or necroptotic cell death pathway. When the NLRP3-ASC-caspase-1 inflammasome-induced pathway was inhibited by short hairpin RNA (shRNA), HBoV1-induced cell death dropped significantly; thus, NLRP3 mediated by ASC appears to be the pattern recognition receptor driving HBoV1 infection-induced pyroptosis. HBoV1 infection induced steady increases in the expression of interleukin 1α (IL-1α) and IL-18. HBoV1 infection was also associated with the marked expression of the antiapoptotic genes BIRC5 and IFI6 When the expression of BIRC5 and/or IFI6 was inhibited by shRNA, the infected cells underwent apoptosis rather than pyroptosis, as indicated by increased cleaved caspase-3 levels and the absence of caspase-1. BIRC5 and/or IFI6 gene inhibition also significantly reduced HBoV1 replication. Thus, HBoV1 infection of human airway epithelial cells activates antiapoptotic proteins that suppress apoptosis and promote pyroptosis. This response may have evolved to confer a replicative advantage, thus allowing HBoV1 to establish a persistent airway epithelial infection. This is the first report of pyroptosis in airway epithelia infected by a respiratory virus.IMPORTANCE Microbial infection of immune cells often induces pyroptosis, which is mediated by a cytosolic protein complex called the inflammasome that senses microbial pathogens and then activates the proinflammatory cytokines IL-1 and IL-18. While virus-infected airway epithelia often activate NLRP3 inflammasomes, studies to date suggest that these viruses kill the airway epithelial cells via the apoptotic or necrotic pathway; involvement of the pyroptosis pathway has not been reported previously. Here, we show for the first time that virus infection of human airway epithelia can also induce pyroptosis. Human bocavirus 1 (HBoV1), a human parvovirus, causes lower respiratory tract infections in young children. This study indicates that HBoV1 kills airway epithelial cells by activating genes that suppress apoptosis and thereby promote pyroptosis. This strategy appears to promote HBoV1 replication and may have evolved to allow HBoV1 to establish persistent infection of human airway epithelia.

Primary tracheal schwannoma a review of a rare entity: current understanding of management and followup

BackgroundNeurogenic tumors of the tracheobronchial tree are extremely rare and include neurofibroma and schwannoma. We report a case of primary recurrent tracheal schwannoma causing obstructive airway symptoms.Case presentationA 60-year-old man presented with obstructive airway symptoms due to recurrent tracheal schwannoma. Due the recurrence, size of the tumor and low surgical risk, the patient was treated with tracheal resection.ConclusionPrimary endotracheal neurogenic tumors are extremely rare, but one should consider them in the differential diagnosis of persistent upper airway symptoms. While endoscopic therapies recur nearly a quarter of the time, surgical resections do not have any recorded recurrences.

Lacrimal Sac Pneumatocele Following Blunt Nasal Trauma

Pneumatocele of the lacrimal sac is an uncommon entity and has been rarely reported in literature. The valvular function of the Hasner's valve at the lower end of nasolacrimal duct is presumed to prevent the retrograde reflux of air into the lacrimal sac with increased intranasal pressure as in valsalva maneuver. Loss of this valvular function as noted with persistent positive airway pressure ventilation can cause retrograde air reflux into lacrimal sac. The authors report a case of lacrimal sac pneumatocele which developed following blunt nasal trauma involving the bony nasolacrimal duct.

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OBJECTIVES/SPECIFIC AIMS: Obstructive lung disease following particulate matter (PM) exposure is a major health concern. Coexisting metabolic syndrome (MetSyn) often occurs. Receptor for advanced glycation end products (RAGE) is highly expressed in the lung, is a strong predictor of FEV1, and is a key mediator of MetSyn. To determine if the loss of RAGE protects from the persistence of effects of particulate associated lung injury in a murine model. METHODS/STUDY POPULATION: Wild type (WT) and RAGE knockout (RKO) mice were exposed to 100 μg of PM (WTC-Aggregate, PM53) or PBS control by oropharyngeal aspiration. Lung function, methacholine challenge, and bronchoalveolar lavage (BAL) were quantified 28 days after PM exposure using flexiVent (Scireq Montreal, QC). BAL was obtained and cell differentials, cytokines and transcription factors were assayed. Bio-volume to airspace ratio and mean chord length were measured (Image J and Adobe Photoshop). RESULTS/ANTICIPATED RESULTS: WT mice were hyper-reactive to methacholine compared with their PBS controls 28 days after a single exposure to PM. They recovered from increased neutrophilia, loss of FEV, decreased compliance, and increased resistance, which were previously observed 24-hours after exposure. RKO were not hyper-reactive when compared with their own PBS controls. Lung histology shows persistence of loss of alveolar space in WT mice exposed to PM after 28 days. Area fraction was significantly higher in PM exposed WT mice after 28 days which was not significant after 24 hours. Mean chord length was significantly shorter for PM exposed at both time points for WT mice. The relative expression of phosphorylated to total CREB and ERK1/2 proteins was lower in RKO PM exposed mice compared with WT PM while STAT3 expression was lower in WT PM compared with WT PBS. PM induced a lower fold change of total proteins from the PBS controls in RKO for CREB, p38, ERK1/2, STAT3, and STAT5. JNK and p70S6k total proteins expressed a decreased fold change in WT PM exposed mice compared with WT PBS controls. DISCUSSION/SIGNIFICANCE OF IMPACT: A single dose of PM can produce persistent airway hyper-reactivity after 28 days of exposure. This PM induced injury is alleviated in the absence of RAGE, similar to what was seen at 24 hours. Inhibiting RAGE may be key to limiting the persistent inflammatory effects of high intensity PM exposure.

Case-Finding for Persistent Airway Obstruction in Farmers: A Questionnaire With Optimal Diagnosis Criteria

Appropriate identification of subjects who are candidates for spirometry through case-finding questionnaires may help solve the problem of chronic obstructive pulmonary disease misdiagnosis. The performance of case-finding questionnaires depends at least partially on the characteristics of the population used for their development. The use of an accurate threshold for the forced expiratory volume in 1 second / forced vital capacity ratio to define persistent airway obstruction is also vital in ascertaining chronic obstructive pulmonary disease. Using a population examined between October 2012 and May 2013 that included a large subset of agricultural workers both exposed and unexposed to tobacco smoking, the authors aimed to select a combination of items that would identify persons most likely to have persistent airway obstruction defined as forced expiratory volume in 1 second / forced vital capacity less than the lower limit of normal according to the Global Lung Initiative-2012 equations. Two thirds of the population (n=3,397) were randomly selected to develop a questionnaire, and one third (n=1,698) was reserved for questionnaire validation. Statistical analysis was performed in 2016. The selected items were sex, dyspnea, BMI, tobacco smoking habits, age, history of respiratory diseases, and history of occupation at risk. The C-index of the model was 0.84 (95% CI=0.80, 0.88) for the development population and 0.76 (95% CI=0.66, 0.86) for the validation population. Using the selected items in combination, the sensitivity and specificity in identifying persistent airway obstruction were 76% and 77%, respectively, in the development population (and 68% and 73%, respectively, in the validation population) for a threshold value of 2.50%. This seven-item questionnaire is the first developed from a population comprising a large subset of agricultural workers and using the Global Lung Initiative-2012 equations.

Mepolizumab for the treatment of severe eosinophilic asthma.

Published data on the pharmacology, pharmacokinetics and pharmacodynamics, and clinical efficacy and safety of the interleukin-5 antagonist mepolizumab are reviewed. Asthma of the eosinophilic phenotype is characterized by persistent eosinophilic airway inflammation promoted primarily by T-helper type 2 cytokines, the key regulator of eosinophils. Patients with severe eosinophilic asthma are burdened by the need to administer high doses of corticosteroids to help manage their symptoms. In November 2015, mepolizumab (Nucala, GlaxoSmithKline) gained U.S. marketing approval for use as an add-on maintenance treatment for severe eosinophilic asthma in patients 12 years of age or older, making it the first personalized targeted therapy for this population. Efficacy results from clinical trials provided evidence of the corticosteroid-sparing effects of mepolizumab and its ability to reduce both blood and sputum eosinophil counts. Safety data from several Phase II or III studies involving a total of more than 1,300 patients indicated that mepolizumab was generally well tolerated, and types and rates of adverse events in mepolizumab recipients were comparable to those reported with placebo use; the only mepolizumab-associated serious adverse drug events were asthma exacerbations in 2 patients. The recommended dosage of mepolizumab is 100 mg administrated via subcutaneous injection every 4 weeks. Mepolizumab is a safe and efficacious novel add-on therapy for a small subgroup of patients with severe eosinophilic asthma whose asthma is not adequately controlled by standard regimens for asthma treatment.

In Vitro and In Vivo Studies of Alar-Nasal Cartilage Using Autologous Micro-Grafts: The Use of the Rigenera® Protocol in the Treatment of an Osteochondral Lesion of the Nose.

Cartilage defects represent a serious problem due to the poor regenerative properties of this tissue. Regarding the nose, nasal valve collapse is associated with nasal blockage and persistent airway obstruction associated with a significant drop in the quality of life for patients. In addition to surgical techniques, several cell-based tissue-engineering strategies are studied to improve cartilage support in the nasal wall, that is, to ameliorate wall insufficiency. Nevertheless, there are no congruent data available on the benefit for patients during the follow-up time. In this manuscript, we propose an innovative approach in the treatment of cartilage defects in the nose (nasal valve collapse) based on autologous micro-grafts obtained by mechanical disaggregation of a small portion of cartilage tissue (Rigenera® protocol). In particular, we first analyzed in vitro murine and human cartilage micro-grafts; secondly, we analyzed the clinical results of a patient with pinched nose deformity treated with autologous micro-grafts of chondrocytes obtained by Rigenera® protocol. The use of autologous micro-graft produced promising results in surgery treatment of cartilage injuries and could be safely and easily administrated to patients with cartilage tissue defects.

Serum YKL-40 levels may help distinguish exacerbation of post-infectious bronchiolitis obliterans from acute bronchiolitis in young children.

Children with post-infectious bronchiolitis obliterans (PIBO) are frequently hospitalized with acute exacerbation, but clinical differentiation of PIBO exacerbation from acute bronchiolitis is often challenging, which may result in treatment delay and chronic lung function impairment. We aimed to examine whether serum YKL-40 and growth factors could be markers for PIBO exacerbation. Thirty-seven children admitted with acute exacerbation of PIBO were enrolled and studied retrospectively. Diagnosis of PIBO was based on clinical history of acute respiratory infection followed by persistent airway obstruction and characteristic findings in high-resolution computed tomography. Serum levels of YKL-40, vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-β1, and platelet-derived growth factor (PDGF)-BB were measured on admission. The biomarkers were also examined in children admitted with acute bronchiolitis serving as positive controls (N = 30) and in age-matched controls (N = 20). Only YKL-40 levels were found to be significantly higher in PIBO patients with exacerbation compared with that in bronchiolitis patients and showed a positive correlation with the severity of disease before diagnosis of PIBO. Conclusion: Our results suggest that measuring serum YKL-40 levels might help distinguish exacerbation of PIBO from acute bronchiolitis in young children. What is Known: • The children with post-infectious BO (PIBO) usually have recurrent wheezing and need frequent hospitalization due to acute exacerbation during the first disease years. • Clinical differentiation of PIBO exacerbation from acute bronchiolitis in young children is often challenging, which may result in treatment delay and chronic lung function impairment. What is New: • Measuring serum YKL-40 levels might help distinguish exacerbation of PIBO from acute bronchiolitis in young children.

P244 Serum YKL-40 levels may help distinguish exacerbation of post-infectious bronchiolitis obliterans from acute bronchiolitis in young children

Introduction: The children with post-infectious bronchiolitis obliterans (PIBO) are frequently hospitalized with acute exacerbation, but clinical differentiation of PIBO exacerbation from ordinary bronchiolitis is often challenging, which may result in treatment delay and chronic lung function impairment. We aimed to examine whether serum YKL-40 and growth factors could be markers for PIBO exacerbation. Methods: Thirty-seven children admitted with acute exacerbation of PIBO were enrolled. Diagnosis of PIBO was based on clinical history of acute respiratory infection followed by persistent airway obstruction and characteristic findings in high-resolution computed tomography. Serum levels of YKL-40, vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-β1 and platelet derived growth factor (PDGF)-BB were measured. The mediators were also examined in the children admitted with acute bronchiolitis serving as positive controls (N=30) and in age-matched controls (N=20). Results: Only YKL-40 levels were found to be significantly higher in PIBO patients with exacerbation compared with bronchiolitis patients and showed a positive correlation with the severity of disease before diagnosis of PIBO. Conclusion: Our results suggest that YKL-40 might be involved in the pathogenesis of PIBO and measuring serum YKL-40 levels might help distinguish exacerbation of PIBO from ordinary acute bronchiolitis in young children.

P136 Pneumonitis and reactive airways dysfunction syndrome with persistent airway obstruction due to inhalation of industrial disinfectant: a case report.

P136 Pneumonitis and reactive airways dysfunction syndrome with persistent airway obstruction due to inhalation of industrial disinfectant: a case report.

Insights on persistent airway infection by non-typeable Haemophilus influenzae in chronic obstructive pulmonary disease.

Non-typeable Haemophilus influenzae (NTHi) is the most common bacterial cause of infection of the lower airways in adults with chronic obstructive pulmonary disease (COPD). Infection of the COPD airways causes acute exacerbations, resulting in substantial morbidity and mortality. NTHi has evolved multiple mechanisms to establish infection in the hostile environment of the COPD airways, allowing the pathogen to persist in the airways for months to years. Persistent infection of the COPD airways contributes to chronic airway inflammation that increases symptoms and accelerates the progressive loss of pulmonary function, which is a hallmark of the disease. Persistence mechanisms of NTHi include the expression of multiple redundant adhesins that mediate binding to host cellular and extracellular matrix components. NTHi evades host immune recognition and clearance by invading host epithelial cells, forming biofilms, altering gene expression and displaying surface antigenic variation. NTHi also binds host serum factors that confer serum resistance. Here we discuss the burden of COPD and the role of NTHi infections in the course of the disease. We provide an overview of NTHi mechanisms of persistence that allow the pathogen to establish a niche in the hostile COPD airways.

Targeting Interleukin-17 signalling in cigarette smoke-induced lung disease: Mechanistic concepts and therapeutic opportunities.

It is widely accepted that compromised lung function in chronic obstructive pulmonary disease (COPD) is, at least in part, a consequence of persistent airway inflammation caused by particles and noxious gases present in cigarette smoke and indoor air pollution from burning biomass fuel. Currently, the World Health Organization estimates that 80 million people have moderate or severe COPD worldwide. While there is a global need for effective medical treatment, current therapeutic interventions have shown limited success in preventing disease pathology and progression. This is, in large part, due to the complexity and heterogeneity of COPD, and an incomplete understanding of the molecular mechanisms governing inflammatory processes in individual patients. This review discusses recent discoveries related to the pro-inflammatory cytokine interleukin (IL)-17A, and its potential role in the pathogenesis of COPD. We propose that an intervention strategy targeting IL-17 signalling offers an exciting opportunity to mitigate inflammatory processes, and prevent the progression of tissue pathologies associated with COPD.

Secretory IgA Deficiency in Individual Small Airways Is Associated with Persistent Inflammation and Remodeling.

Maintenance of a surface immune barrier is important for homeostasis in organs with mucosal surfaces that interface with the external environment; however, the role of the mucosal immune system in chronic lung diseases is incompletely understood. We examined the relationship between secretory IgA (SIgA) on the mucosal surface of small airways and parameters of inflammation and airway wall remodeling in chronic obstructive pulmonary disease (COPD). We studied 1,104 small airways (<2 mm in diameter) from 50 former smokers with COPD and 39 control subjects. Small airways were identified on serial tissue sections and examined for epithelial morphology, SIgA, bacterial DNA, nuclear factor-κB activation, neutrophil and macrophage infiltration, and airway wall thickness. Morphometric evaluation of small airways revealed increased mean airway wall thickness and inflammatory cell counts in lungs from patients with COPD compared with control subjects, whereas SIgA level on the mucosal surface was decreased. However, when small airways were classified as SIgA intact or SIgA deficient, we found that pathologic changes were localized almost exclusively to SIgA-deficient airways, regardless of study group. SIgA-deficient airways were characterized by (1) abnormal epithelial morphology, (2) invasion of bacteria across the apical epithelial barrier, (3) nuclear factor-κB activation, (4) accumulation of macrophages and neutrophils, and (5) fibrotic remodeling of the airway wall. Our findings support the concept that localized, acquired SIgA deficiency in individual small airways of patients with COPD allows colonizing bacteria to cross the epithelial barrier and drive persistent inflammation and airway wall remodeling, even after smoking cessation.

Serum IL-1β and IL-17 levels in patients with COPD: associations with clinical parameters.

COPD is a chronic airway inflammatory disease characterized mainly by neutrophil airway infiltrations. Interleukin (IL)-1β and IL-17 are the key mediators of neutrophilic airway inflammation in COPD. This study was undertaken to evaluate the serum IL-1β and IL-17 levels and associations between these two key mediators with clinical parameters in COPD patients. Serum samples were collected from 60 COPD subjects during the acute exacerbation of COPD, 60 subjects with stable COPD and 40 healthy control subjects. Commercial enzyme-linked immunosorbent assay kits were used to measure the serum IL-1β and IL-17 concentrations. The association between serum IL-1β and IL-17 with FEV1% predicted, C-reactive protein, neutrophil percentage and smoking status (pack-years) was assessed in the COPD patients. We found that serum IL-1β and IL-17 levels in acute exacerbation of COPD subjects were significantly higher than that in stable COPD or control subjects and were positively correlated to serum C-reactive protein levels, neutrophil % and smoking status (pack-years) but negatively correlated with FEV1% predicted in COPD patients. More importantly, serum IL-1β levels were markedly positively associated with serum IL-17 levels in patients with COPD (P=0.741, P<0.001). In conclusion, elevated serum IL-1β and IL-17 levels may be used as a biomarker for indicating persistent neutrophilic airway inflammation and potential ongoing exacerbation of COPD.

Posterior tracheopexy for severe tracheomalacia

PurposeIn severe tracheomalacia, aortopexy addresses anterior vascular compression, but does not directly address posterior membranous tracheal intrusion. We review patient outcomes of posterior tracheopexy for tracheomalacia with posterior intrusion to determine if there were resolution of clinical symptoms and bronchoscopic evidence of improvement in airway collapse. MethodsAll patients who underwent posterior tracheopexy from October 2012 to March 2016 were retrospectively reviewed. Clinical symptoms, tracheomalacia scores based on standardized dynamic airway evaluation by anatomical region, and persistent airway intrusion were collected. Data were analyzed by Wald and Wilcoxon signed-ranks tests. Results98 patients (51% male) underwent posterior tracheopexy at a median age of 15months (IQR 6–33months). Median follow-up was 5months (range 0.25–36months). There were statistically significant improvements in clinical symptoms postoperatively, including cough, noisy breathing, prolonged and recurrent respiratory infections, transient respiratory distress requiring positive pressure, oxygen dependence, blue spells, and apparent life-threatening events (p<0.001), as well as ventilator dependence (p=0.04). Tracheomalacia scores on bronchoscopy improved significantly in all regions of the trachea and bronchi (p<0.001). 9.2% had persistent airway intrusion requiring reoperation, usually with aortopexy. ConclusionsPosterior tracheopexy is effective in treating severe tracheomalacia with significant improvements in clinical symptoms and degree of airway collapse on bronchoscopy. Level of evidenceLevel III, treatment study.

The Lymphatic Phenotype of Lung Allografts in Patients With Bronchiolitis Obliterans Syndrome and Restrictive Allograft Syndrome.

Chronic lung allograft dysfunction (CLAD), presenting as bronchiolitis obliterans syndrome (BOS) or restrictive allograft syndrome (RAS) is the major limiting factor of long-term survival in lung transplantation. Its pathogenesis is still obscure. In BOS, persistent alloimmune injury and chronic airway inflammation are suggested. One of the main tasks of the lymphatic vessel (LV) system is the promotion of immune cell trafficking. The formation of new LVs has been shown to trigger chronic allograft rejection in kidney transplants. We therefore sought to address the role of lymphangiogenesis in CLAD. Formalin-fixed paraffin-embedded tissue samples of 22 patients receiving a lung retransplantation due to BOS or RAS were collected. Lymphatic vessel density (LVD) was determined by immunohistochemical staining for podoplanin. Lung tissue obtained from 13 non-CLAD patients served as control. The impact of LVD on graft survival was assessed. Lymphatic vessel density in CLAD patients did not differ from those in control subjects (median number of LVs per bronchiole: 4.75 (BOS), 6.47 (RAS), 4.25 (control), P = 0.97). Moreover, the number of LVs was not associated with regions of cellular infiltrates (median number of LVs per bronchiole: with infiltrates, 5.00 (BOS), 9.00 (RAS), 4.00 (control), P = 0.62; without infiltrates, 4.5 (BOS), 0.00 (RAS), 4.56 (control), P = 0.74). Lymphatic vessel density did not impact the time to development of BOS or RAS in lung transplantation (low vs high LVD: 38.5 vs 86.0 months, P = 0.15 [BOS]; 60.5 vs 69.5 months, P = 0.80 [RAS]). Unlike chronic organ failure in kidney transplantation, lymphangiogenesis is not altered in CLAD patients. Our findings highlight unique immunological processes leading to BOS and RAS.

Oligonucleotide Therapy for Obstructive and Restrictive Respiratory Diseases.

Inhaled oligonucleotide is an emerging therapeutic modality for various common respiratory diseases, including obstructive airway diseases like asthma and chronic obstructive pulmonary disease (COPD) and restrictive airway diseases like idiopathic pulmonary fibrosis (IPF). The advantage of direct accessibility for oligonucleotide molecules to the lung target sites, bypassing systemic administration, makes this therapeutic approach promising with minimized potential systemic side effects. Asthma, COPD, and IPF are common chronic respiratory diseases, characterized by persistent airway inflammation and dysregulated tissue repair and remodeling, although each individual disease has its unique etiology. Corticosteroids have been widely prescribed for the treatment of asthma, COPD, and IPF. However, the effectiveness of corticosteroids as an anti-inflammatory drug is limited by steroid resistance in severe asthma, the majority of COPD cases, and pulmonary fibrosis. There is an urgent medical need to develop target-specific drugs for the treatment of these respiratory conditions. Oligonucleotide therapies, including antisense oligonucleotide (ASO), small interfering RNA (siRNA), and microRNA (miRNA) are now being evaluated both pre-clinically and clinically as potential therapeutics. The mechanisms of action of ASO and siRNA are highly target mRNA specific, ultimately leading to target protein knockdown. miRNA has both biomarker and therapeutic values, and its knockdown by a miRNA antagonist (antagomir) has a broader but potentially more non-specific biological outcome. This review will compile the current findings of oligonucleotide therapeutic targets, verified in various respiratory disease models and in clinical trials, and evaluate different chemical modification approaches to improve the stability and potency of oligonucleotides for the treatment of respiratory diseases.

Asthma-chronic obstructive pulmonary disease overlap syndrome – Literature review and contributions towards a Portuguese consensus

IntroductionPhenotypic overlap between the two main chronic airway pulmonary diseases, asthma and chronic obstructive pulmonary disease (COPD), has been the subject of debate for decades, and recently the nomenclature of asthma-COPD overlap syndrome (ACOS) was adopted for this condition. The definition of this entity in the literature is, however, very heterogeneous, it is therefore important to define how it applies to Portugal. MethodsA literature review of ACOS was made in a first phase resulting in the drawing up of a document that was later submitted for discussion among a panel of chronic lung diseases experts, resulting in reflexions about diagnosis, treatment and clinical guidance for ACOS patients. ResultsThere was a consensus among the experts that the diagnosis of ACOS should be considered in the concomitant presence of: clinical manifestations characteristic of both asthma and COPD, persistent airway obstruction (post-bronchodilator FEV1/FVC<0.7), positive response to bronchodilator test (increase in FEV1 of ≥200mL and ≥12% from baseline) and current or past history of smoking or biomass exposure. In reaching diagnosis, the presence of peripheral eosinophilia (>300eosinophils/μL or >5% of leukocytes) and previous history of atopy should also be considered. The recommended first line pharmacological treatment in these patients is the ICS/LABA association; if symptomatic control is not achieved or in case of clinical severity, triple therapy with ICS/LABA/LAMA may be used. An effective control of the exposure to risk factors, vaccination, respiratory rehabilitation and treatment of comorbidities is also important. ConclusionsThe creation of initial guidelines on ACOS, which can be applied in the Portuguese context, has an important role in the generation of a broad nationwide consensus. This will give, in the near future, a far better clinical, functional and epidemiological characterization of ACOS patients, with the ultimate goal of achieving better therapeutic guidance.