Bronchial thermoplasty for severe asthma

MiR-185-5p measurement assists in reflecting Th1/Th2 cell imbalance, inflammatory cytokine production, and exacerbation risk for childhood asthma

BACKGROUND

MicroRNA (miR)-185-5p participates in the pathology of asthma by regulating immune imbalance, inflammation, periostin synthesis, and smooth muscle contraction. This study intended to explore the dysregulation of miR-185p and its correlation with T-helper (Th)1, Th2 cells, and inflammatory cytokines in childhood asthma.

METHODS

In 150 childhood asthma patients and 30 healthy controls (HCs), miR-185-5p from peripheral blood mononuclear cells was detected using reverse transcription-quantitative polymerase chain reaction, Th cells from peripheral blood samples were detected using flow cytometry, inflammatory cytokines from serum samples were detected using enzyme-linked immunosorbent assay.

RESULTS

MiR-185-5p was increased in childhood asthma patients versus HCs [median (interquartile range (IQR)): 2.315 (1.770-3.855) versus 1.005 (0.655-1.520)] (P < 0.001). Meanwhile, miR-185-5p was negatively associated with Th1 cells (P = 0.035) but positively correlated with Th2 cells (P = 0.006) and IL-4 (P = 0.003) in childhood asthma patients; however, miR-185-5p was not linked to Th1 cells, Th2 cells, IFN-γ, or IL-4 in HCs (all P > 0.05). In addition, miR-185-5p was positively related to TNF-α (P < 0.001), IL-1β (P = 0.015), and IL-6 (P = 0.008) in childhood asthma patients, miR-185-5p was only linked to TNF-α (P = 0.040) but not IL-1β or IL-6 (both P > 0.05) in HCs. Moreover, miR-185-5p was increased in exacerbated childhood asthma patients versus remissive patients [median (IQR): 3.170 (2.070-4.905) versus 1.900 (1.525-2.615)] (P < 0.001). Besides, miR-185-5p was highest in patients with severe exacerbation followed by patients with moderate exacerbation, and lowest in patients with mild exacerbation (P = 0.010).

CONCLUSION

MiR-185-5p is associated with imbalanced Th1/Th2 cells, increased inflammatory cytokines along with elevated exacerbation risk, and severity in childhood asthma patients.

State of the Art: Interventional Pulmonology

Interventional pulmonology (IP) has evolved over the past decade from an obscure subspecialty in pulmonary medicine to a recognized discipline offering advanced consultative and procedural services to patients with thoracic malignancy, anatomic airway disease, and pleural disease. Innovative interventions are now also available for diseases not traditionally treated procedurally, such as asthma and emphysema. The IP field has established certification examinations and training standards for IP training programs in an effort to enhance training quality and ensure competency. Validating new technology and proving its cost-effectiveness and effect on patient outcomes present the biggest challenge to IP as the health-care environment marches toward value-based health care. High-quality research is now thriving in IP and promises to elevate its practice into patient-centric evidence-based care.

Airway smooth muscle cells are insensitive to the anti-proliferative effects of corticosteroids: The novel role of insulin growth factor binding Protein-1 in asthma

Airway remodeling in asthma manifests, in part, as enhanced airway smooth muscle (ASM) mass, due to myocyte proliferation. While the anti-proliferative effects of glucocorticoid (GC) were investigated in normal ASM cells (NASMC), little is known about such effects in ASM cells derived from asthma subjects (AASMC). We posit that GC differentially modulates mitogen-induced proliferation of AASMC and NASMC. Cells were cultured, starved, then treated with Epidermal growth factor (EGF) (10 ng/ml) and Platelet-derived growth factor (PDGF) (10 ng/ml) for 24 h and/or fluticasone propionate (FP) (100 nM) added 2 h before. Cell counts and flow cytometry analyses showed that FP failed to decrease the cell number of and DNA synthesis in AASMC irrespective of mitogens used. We also examine the ability of Insulin Growth Factor Binding Protein-1 (IGFBP-1), a steroid-inducible gene that deters cell growth in other cell types, to inhibit proliferation of AASMC where FP failed. We found that FP increased IGFBP1 mRNA and protein levels. Interestingly, the addition of IGFBP1 (1 μg/ml) to FP completely inhibited the proliferation of AASMC irrespective to the mitogens used. Further investigation of different signaling molecules involved in ASM growth and GC receptor functions (Protein kinase B (PKB/AKT), Mitogen-activated protein kinases (MAPKs), Focal Adhesion Kinase (FAK)) showed that IGFBP-1 selectively decreased mitogen-induced p38 phosphorylation in AASMC. Collectively, our results show the insensitivity of AASMC to the anti-proliferative effects of GC, and demonstrate the ability of IGFBP1 to modulate AASMC growth representing, hence, a promising strategy to control ASM growth in subjects with GC insensitive asthma.

Future perspectives of anticholinergics for the treatment of asthma in adults and children

Despite major advances in therapeutic interventions and the availability of detailed treatment guidelines, a high proportion of patients with symptomatic asthma remain uncontrolled. Asthma management is largely guided by the Global Initiative for Asthma (GINA) strategy and is based on a backbone of inhaled corticosteroid (ICS) therapy with the use of additional therapies to achieve disease control. Inhaled long-acting bronchodilators alone and in combination are the preferred add-on treatment options. Although long-acting muscarinic antagonists (LAMAs) are a relatively recent addition to disease management recommendations for asthma, tiotropium has been extensively studied in a large clinical trial program. In Europe and the United States, tiotropium is approved for patients aged ≥6 years and uncontrolled on medium- to high-dose ICS/long-acting β2-agonists at GINA Steps 4 and 5 with a history of exacerbations. Evidence supports the efficacy of tiotropium Respimat® in adults in terms of lung function and asthma control, with a safety profile comparable with that of placebo across a range of asthma severities. Similarly, clinical trials in patients aged 1-17 years have shown improvements in lung function and trends toward improved asthma control. Furthermore, its efficacy makes tiotropium relatively easy to incorporate into routine clinical practice, irrespective of allergic status and without the need for patient phenotyping. Tiotropium is a cost-effective treatment that may offer an important alternative to other, more expensive add-on therapies. This review discusses the potential future position of LAMAs in clinical practice by considering the continuously evolving evidence. Prominence is given to tiotropium, the only LAMA supported by a structured clinical trial program in asthma to date, while also considering other recommended treatment options for patients with uncontrolled asthma. The importance of effective patient/caregiver-clinician communication and shared decision-making in enhancing treatment adherence is also highlighted.

Barriers to achieving asthma control in adults: evidence for the role of tiotropium in current management strategies

Despite the availability of a range of treatment options and management guidelines, a high proportion of adults with asthma remain uncontrolled. The challenge of managing uncontrolled asthma includes providing efficacious treatment while limiting side effects, recognizing situations when a change in asthma therapy is required, and considering patient preferences and satisfaction. In line with the Global Initiative for Asthma report, asthma management is based on a backbone of inhaled corticosteroid (ICS) therapy and use of add-on therapies to achieve disease control. This review considers whether add-on options could be better utilized in clinical practice. A number of long-acting muscarinic antagonists are in development, but tiotropium is the most widely studied for use in asthma. Evidence demonstrating the efficacy of tiotropium as an add-on therapy to at least ICS in adults with symptomatic mild, moderate, and severe asthma is presented from randomized controlled trials and real-world evidence. In addition, the benefit of tiotropium therapy in a wide range of patient phenotypes and disease severities without the need for biomarker assessment is discussed. Additional strategies that complement this approach, such as recognizing and overcoming barriers to adherence, ensuring optimal device use, and education and support to enhance patient–physician communication, are discussed. Physician education can also help raise awareness that additional management options are available for patients with moderate-to-severe asthma who remain uncontrolled on ICS/long-acting β₂-agonist treatment.

New targets for resolution of airway remodeling in obstructive lung diseases

Airway remodeling (AR) is a progressive pathological feature of the obstructive lung diseases, including asthma and chronic obstructive pulmonary disease (COPD). The pathology manifests itself in the form of significant, progressive, and (to date) seemingly irreversible changes to distinct respiratory structural compartments. Consequently, AR correlates with disease severity and the gradual decline in pulmonary function associated with asthma and COPD. Although current asthma/COPD drugs manage airway contraction and inflammation, none of these effectively prevent or reverse features of AR. In this review, we provide a brief overview of the features and putative mechanisms affecting AR. We further discuss recently proposed strategies with promise for deterring or treating AR.

Tomatidine Attenuates Airway Hyperresponsiveness and Inflammation by Suppressing Th2 Cytokines in a Mouse Model of Asthma

Tomatidine is isolated from the fruits of tomato plants and found to have anti-inflammatory effects in macrophages. In the present study, we investigated whether tomatidine suppresses airway hyperresponsiveness (AHR) and eosinophil infiltration in asthmatic mice. BALB/c mice were sensitized with ovalbumin and treated with tomatidine by intraperitoneal injection. Airway resistance was measured by intubation analysis as an indication of airway responsiveness, and histological studies were performed to evaluate eosinophil infiltration in lung tissue. Tomatidine reduced AHR and decreased eosinophil infiltration in the lungs of asthmatic mice. Tomatidine suppressed Th2 cytokine production in bronchoalveolar lavage fluid. Tomatidine also blocked the expression of inflammatory and Th2 cytokine genes in lung tissue. In vitro, tomatidine inhibited proinflammatory cytokines and CCL11 production in inflammatory BEAS-2B bronchial epithelial cells. These results indicate that tomatidine contributes to the amelioration of AHR and eosinophil infiltration by blocking the inflammatory response and Th2 cell activity in asthmatic mice.

An Official American Thoracic Society Research Statement: Current Challenges Facing Research and Therapeutic Advances in Airway Remodeling

BACKGROUND

Airway remodeling (AR) is a prominent feature of asthma and other obstructive lung diseases that is minimally affected by current treatments. The goals of this Official American Thoracic Society (ATS) Research Statement are to discuss the scientific, technological, economic, and regulatory issues that deter progress of AR research and development of therapeutics targeting AR and to propose approaches and solutions to these specific problems. This Statement is not intended to provide clinical practice recommendations on any disease in which AR is observed and/or plays a role.

METHODS

An international multidisciplinary group from within academia, industry, and the National Institutes of Health, with expertise in multimodal approaches to the study of airway structure and function, pulmonary research and clinical practice in obstructive lung disease, and drug discovery platforms was invited to participate in one internet-based and one face-to-face meeting to address the above-stated goals. Although the majority of the analysis related to AR was in asthma, AR in other diseases was also discussed and considered in the recommendations. A literature search of PubMed was performed to support conclusions. The search was not a systematic review of the evidence.

RESULTS

Multiple conceptual, logistical, economic, and regulatory deterrents were identified that limit the performance of AR research and impede accelerated, intensive development of AR-focused therapeutics. Complementary solutions that leverage expertise of academia and industry were proposed to address them.

CONCLUSIONS

To date, numerous factors related to the intrinsic difficulty in performing AR research, and economic forces that are disincentives for the pursuit of AR treatments, have thwarted the ability to understand AR pathology and mechanisms and to address it clinically. This ATS Research Statement identifies potential solutions for each of these factors and emphasizes the importance of educating the global research community as to the extent of the problem as a critical first step in developing effective strategies for: (1) increasing the extent and impact of AR research and (2) developing, testing, and ultimately improving drugs targeting AR.

Bronchial thermoplasty: activations predict response

Background

Bronchial thermoplasty (BT) is an emerging bronchoscopic intervention for the treatment of severe asthma. The predictive factors for clinical response to BT are unknown. We examined the relationship between the number of radiofrequency activations applied and the treatment response observed.

Methods

Data were collected from 24 consecutive cases treated at three Australian centres from June 2014 to March 2016. The baseline characteristics were collated along with the activations delivered. The primary response measure was change in the Asthma Control Questionnaire-5 (ACQ-5) score measured at 6 months post BT. The relationship between change in outcome parameters and the number of activations delivered was explored.

Results

All patients met the ERS/ATS definition for severe asthma. At 6 months post treatment, mean ACQ-5 improved from 3.3 ± 1.1 to 1.5 ± 1.1, p < 0.001. The minimal clinically significant improvement in ACQ-5 of ≥0.5 was observed in 21 out of 24 patients. The only significant variable that differed between the 21 responders and the three non-responders was the number of activations delivered, with 139 ± 11 activations in the non-responders, compared to 221 ± 45 activations in the responders (p < 0.01). A significant inverse correlation was found between change in ACQ-5 score and the number of activations, r = −0.43 (p < 0.05).

Conclusions

The number of activations delivered during BT has a role in determining clinical response to treatment.

Effectiveness of bronchial thermoplasty in patients with severe refractory asthma: Clinical and histopathologic correlations

BACKGROUND

The effectiveness of bronchial thermoplasty (BT) has been reported in patients with severe asthma, yet its effect on different bronchial structures remains unknown.

OBJECTIVE

We sought to examine the effect of BT on bronchial structures and to explore the association with clinical outcome in patients with severe refractory asthma.

METHODS

Bronchial biopsy specimens (n = 300) were collected from 15 patients with severe uncontrolled asthma before and 3 months after BT. Immunostained sections were assessed for airway smooth muscle (ASM) area, subepithelial basement membrane thickness, nerve fibers, and epithelial neuroendocrine cells. Histopathologic findings were correlated with clinical parameters.

RESULTS

BT significantly improved asthma control and quality of life at both 3 and 12 months and decreased the numbers of severe exacerbations and the dose of oral corticosteroids. At 3 months, this clinical benefit was accompanied by a reduction in ASM area (median values before and after BT, respectively: 19.7% [25th-75th interquartile range (IQR), 15.9% to 22.4%] and 5.3% [25th-75th IQR], 3.5% to 10.1%, P < .001), subepithelial basement membrane thickening (4.4 μm [25th-75th IQR, 4.0-4.7 μm] and 3.9 μm [25th-75th IQR, 3.7-4.6 μm], P = 0.02), submucosal nerves (1.0 ‰ [25th-75th IQR, 0.7-1.3 ‰] immunoreactivity and 0.3 ‰ [25th-75th IQR, 0.1-0.5 ‰] immunoreactivity, P < .001), ASM-associated nerves (452.6 [25th-75th IQR, 196.0-811.2] immunoreactive pixels per mm² and 62.7 [25th-75th IQR, 0.0-230.3] immunoreactive pixels per mm², P = .02), and epithelial neuroendocrine cells (4.9/mm² [25th-75th IQR, 0-16.4/mm²] and 0.0/mm² [25th-75th IQR, 0-0/mm²], P = .02). Histopathologic parameters were associated based on Asthma Control Test scores, numbers of exacerbations, and visits to the emergency department (all P ≤ .02) 3 and 12 months after BT.

CONCLUSION

BT is a treatment option in patients with severe therapy-refractory asthma that downregulates selectively structural abnormalities involved in airway narrowing and bronchial reactivity, particularly ASM, neuroendocrine epithelial cells, and bronchial nerve endings.

Surgical treatment of bronchial asthma by resection of the laryngeal nerve

BACKGROUND

Management of asthma in chronically affected patients is a serious health problem. Our aim was to show that surgical treatment of chronic bronchial asthma by unilateral resection of the internal branch of the superior laryngeal nerve (ib-SLN) is an adequateand lasting remedial response.

PATIENTS AND METHODS

In a retrospective study, 41 (26 male and 15 female) patients with bronchial chronic asthma were treated surgically during the period between 2005 and 2013. It consisted of a unilateral resection of the ib-SLN under optical zoom, on patients placed in supinator position. 35 patients (24 male and 11 female) who were un-operated were included as a control.

RESULTS

In all patients, medication was reduced progressively. When the results were compared with the control group, it was seen that in 26% of the patients, both forced expiratory volume (FEV) and peak expiratory flow (PEF) increased significantly (p <05) and only modestly in 53.6% of patients (FEV, p <05 and PEF, p <05). In the remaining 20% of patients, these parameters remained however unchanged. Overall, in 80% of patients unilateral resection of the ib-SLN gave satisfactory results because it shortened the intervals and duration of asthmatic attacks, rendering thereby a reduction in medication.

CONCLUSION

This minimal-invasive method helped prevent/cure asphyxias in chronic bronchial asthma without affecting cough reflex,respiratory control and phonation and it helped patients avoid severe crisis. This approach is of interest for patients with severe and/or uncontrolled bronchial asthma in settings with limited access to drug treatment.

Severe asthma in childhood: diagnostic and management challenges

PURPOSE OF REVIEW

Problematic severe asthma is a heterogeneous disease with multiple phenotypes. It is rare (<5% of children with asthma), but accounts for 30-50% of all pediatric asthma healthcare costs. This review looks into the currently used management strategies and the innovative treatments, considering both conventional medications and innovative biological therapies for targeting airway inflammation.

RECENT FINDINGS

Patients with problematic severe asthma should be seen by pediatric asthma specialists using a stepwise approach. The first step is to exclude alternative diagnoses; the second is to consider and exclude comorbidities, and assess adherence to medication; the third step involves identifying the pattern of inflammation; and response to treatment in the fourth. Innovative biological therapies are emerging and healthcare professionals should know how to handle them. Patient phenotyping is the main step towards a targeted therapeutic strategy.

SUMMARY

A careful management is important for children with severe asthma, who form a small but challenging group of patients. More research efforts are needed to enable a personalized medicine and a biomarker-driven approach.

New insights into the treatment of severe asthma in children

Severe asthma accounts for 0.5% of the general paediatric population and 4.5% of children with asthma, representing the major burden of asthma-health-care-associated costs. After ensuring a diagnosis of asthma and excluding difficult-to-treat patients with co-morbidities and non-adherence profiles, there remains children with real therapy-resistant asthma for whom the recommendations are to treat beyond guidelines. We describe new insights into the treatment of severe asthma in children, regarding both "classic drugs" (corticosteroids, bronchodilators) and innovative biological therapies targeting airway inflammation and impaired innate immunity. All of these new avenues remain to be studied and validated in children and will require fine clinical and biological phenotyping.

Computed tomography assessment of airways throughout bronchial tree demonstrates airway narrowing in severe asthma

RATIONALE AND OBJECTIVES

To analyze airway dimensions throughout the bronchial tree in severe asthmatic patients using multidetector row computed tomography (MDCT) focusing on airway narrowing.

MATERIALS AND METHODS

Thirty-two patients with severe asthma underwent automated (BronCare software) analysis of their right lung bronchi, with counts of airways >3 mm long arising from the main bronchi (airway count) and bronchial dimension quantification at segmental and subsegmental levels (lumen area [LA], wall area [WA], and WA%). Focal bronchial stenosis was defined as >50% narrowing of maximal LA on contiguous cross-sectional slices. Severe asthmatics were compared to 13 nonsevere asthmatic patients and nonasthmatic (pooled) subjects (Wilcoxon rank tests, then stepwise logistic regression). Finally, cluster analysis of severe asthmatic patients and stepwise logistic regression identified specific imaging subgroups.

RESULTS

The most significant differences between severe asthmatic patients and the pooled subjects were bronchial stenosis (subsegmental and all bronchi: P < .002) and WA% (P < .0003). Stepwise logistic regression retained WA% as the only explanatory covariable (P = .002). Two identified clusters of severe asthmatic patients differed for parameters characterizing airway narrowing (airway count: P = .0002; focal bronchial stenosis: P = .009). Airway count was as discriminant as forced expiratory volume in 1 second/forced vital capacity (P = .01) to identify patients in each cluster, with both variables being correlated (r = 0.59, P = .005).

CONCLUSIONS

Severe asthma-associated morphologic changes were characterized by focal bronchial stenoses and diffuse airway narrowing; the latter was associated with airflow obstruction. WA%, dependent on airway caliber, is the best parameter to identify severe asthmatic patients from pooled subjects.

Bronchial thermoplasty: a non-pharmacological approach

INTRODUCTION

Asthma is a chronic inflammatory disorder of the airway characterized by the episodic symptoms of breathlessness, wheezes and cough. Even with the use of maximum anti-asthmatic pharmacological treatment sometimes it remains uncontrolled. For such patients, bronchial thermoplasty is the new mode of treatment.

OBJECTIVE

To review published article on bronchial thermoplasty.

METHODS

We identified 102 English articles on PubMed, and 56 were excluded by the abstract. The remaining articles were retrieved for full-text detailed evaluation by authors, and 28 relevant articles were selected for final review.

RESULTS

Bronchial thermoplasty is the radiofrequency ablation of the airway smooth muscle with the help of flexible fiberoptic bronchoscope. It reduces the smooth muscle mass of the bronchial wall and decreases its contractility.

CONCLUSION

Bronchial thermoplasty causes improvement in the quality of life, and causes reduction in the emergency room visit and exacerbation due to asthma. Long-term safety has been established by various prospective studies.

Efficacy and safety of reslizumab in patients with moderate to severe eosinophilic asthma

Reslizumab, a neutralizing anti-IL-5 monoclonal antibody, is a promising adjunctive treatment for severe eosinophilic asthma. Monthly intravenous 3.0 mg/kg reslizumab had resulted in improvements in lung function and asthma control. It is well tolerated and common adverse events include headache, nasopharyngitis and upper respiratory tract infection. Rebound eosinophilia after cessation of reslizumab and attenuation of the treatment response with repeated dosing had been reported. Stringent selection of patients with a high eosinophil burden, who are poorly controlled despite moderate to high doses of inhaled corticosteroid, confers the most significant treatment response. Future trials should compare the dose, delivery platform, frequency of dosing and study combinations with other biologics, which will affect its maximal clinical efficacy.

Efficiency of performing pulmonary procedures in a shared endoscopy unit: procedure time, turnaround time, delays, and procedure waiting time

BACKGROUND

The purpose of this study was to assess the efficiency of performing pulmonary procedures in the endoscopy unit in a large teaching hospital.

METHODS

A prospective study from May 20 to July 19, 2013, was designed. The main outcome measures were procedure delays and their reasons, duration of procedural steps starting from patient's arrival to endoscopy unit, turnaround time, total case durations, and procedure wait time.

RESULTS

A total of 65 procedures were observed. The most common procedure was BAL (61%) followed by TBLB (31%). Overall procedures for 35 (53.8%) of 65 patients were delayed by ≥ 30 minutes, 21/35 (60%) because of "spillover" of the gastrointestinal and surgical cases into the time block of pulmonary procedure. Time elapsed between end of pulmonary procedure and start of the next procedure was ≥ 30 minutes in 8/51 (16%) of cases. In 18/51 (35%) patients there was no next case in the room after completion of the pulmonary procedure. The average idle time of the room after the end of pulmonary procedure and start of next case or end of shift at 5:00 PM if no next case was 58 ± 53 minutes. In 17/51 (33%) patients the room's idle time was >60 minutes. A total of 52.3% of patients had the wait time >2 days and 11% had it ≥ 6 days, reason in 15/21 (71%) being unavailability of the slot.

CONCLUSIONS

Most pulmonary procedures were delayed due to spillover of the gastrointestinal and surgical cases into the block time allocated to pulmonary procedures. The most common reason for difficulty encountered in scheduling the pulmonary procedure was slot unavailability. This caused increased procedure waiting time. The strategies to reduce procedure delays and turnaround times, along with improved scheduling methods, may have a favorable impact on the volume of procedures performed in the unit thereby optimizing the existing resources.

Promising future therapies for asthma

Asthma affects 300 million people worldwide and that number has been increasing especially in developed countries. The current standard of care for asthma treatment is based on 2 key pathological features of asthma, airway inflammation and airway obstruction. Improving bronchodilation can be accomplished with ultra-long acting beta2 agonists or long-acting muscarinic agonists used in combination with inhaled corticosteroids. These combinations have already been used effectively for the treatment of COPD. An inhaled phosphodiesterase inhibitor has been shown to improve bronchodilation and decrease airway inflammation. Directly altering the airway smooth muscle with bronchial thermoplasty in select patients has demonstrated long-term benefits but must be measured with immediate post procedure complications. The development of monoclonal antibodies to directly target specific cytokines has had mixed results. In eosinophilic asthma blocking IL-4, IL-5 and IL-13 have improved asthma outcomes. The promise of more directed therapy for asthma appears closer than ever with increased options available for the clinician in the near future.

Bronchial thermoplasty for moderate or severe persistent asthma in adults

BACKGROUND

Bronchial thermoplasty is a procedure that consists of the delivery of controlled radiofrequency-generated heat via a catheter inserted into the bronchial tree of the lungs through a flexible bronchoscope. It has been suggested that bronchial thermoplasty works by reducing airway smooth muscle, thereby reducing the ability of the smooth muscle to bronchoconstrict. This treatment could then reduce asthma symptoms and exacerbations, resulting in improved asthma control and quality of life.

OBJECTIVES

To determine the efficacy and safety of bronchial thermoplasty in adults with bronchial asthma.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register of Trials (CAGR) up to January 2014.

SELECTION CRITERIA

We included randomised controlled clinical trials that compared bronchial thermoplasty versus any active control in adults with moderate or severe persistent asthma. Our primary outcomes were quality of life, asthma exacerbations and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias.

MAIN RESULTS

We included three trials (429 participants) with differences regarding their design (two trials compared bronchial thermoplasty vs medical management and the other compared bronchial thermoplasty vs a sham intervention) and participant characteristics; one of the studies included participants with more symptomatic asthma compared with the others.The pooled analysis showed improvement in quality of life at 12 months in participants who received bronchial thermoplasty that did not reach the threshold for clinical significance (3 trials, 429 participants; mean difference (MD) in Asthma Quality of Life Questionnaire (AQLQ) scores 0.28, 95% confidence interval (CI) 0.07 to 0.50; moderate-quality evidence). Measures of symptom control showed no significant differences (3 trials, 429 participants; MD in Asthma Control Questionnaire (ACQ) scores -0.15, 95% CI -0.40 to 0.10; moderate-quality evidence). The risk of bias for these outcomes was high because two of the studies did not have a sham intervention for the control group.The results from two trials showed a lower rate of exacerbation after 12 months of treatment for participants who underwent bronchial thermoplasty. The trial with sham intervention showed a significant reduction in the proportion of participants visiting the emergency department for respiratory symptoms, from 15.3% on sham treatment to 8.4% over 12 months following thermoplasty. The trials showed no significant improvement in pulmonary function parameters (with the exception of a greater increase in morning peak expiratory flow (PEF) in one trial). Treated participants who underwent bronchial thermoplasty had a greater risk of hospitalisation for respiratory adverse events during the treatment period (3 trials, 429 participants; risk ratio 3.50, 95% CI 1.26 to 9.68; high-quality evidence), which represents an absolute increase from 2% to 8% (95% CI 3% to 23%) over the treatment period. This means that six of 100 participants treated with thermoplasty (95% CI 1 to 21) would require an additional hospitalisation over the treatment period. No significant difference in the risk of hospitalisation was noted at the end of the treatment period.Bronchial thermoplasty was associated with an increase in respiratory adverse events, mainly during the treatment period. Most of these events were mild or moderate, appeared in the 24-hour post-treatment period, and were resolved within a week.

AUTHORS' CONCLUSIONS

Bronchial thermoplasty for patients with moderate to severe asthma provides a modest clinical benefit in quality of life and lower rates of asthma exacerbation, but no significant difference in asthma control scores. The quality of life findings are at risk of bias, as the main benefits were seen in the two studies that did not include a sham treatment arm. This procedure increases the risk of adverse events during treatment but has a reasonable safety profile after completion of the bronchoscopies. The overall quality of evidence regarding this procedure is moderate. For clinical practice, it would be advisable to collect data from patients systematically in independent clinical registries. Further research should provide better understanding of the mechanisms of action of bronchial thermoplasty, as well as its effect in different asthma phenotypes or in patients with worse lung function.

Nocturnal continuous positive airway pressure in severe non-apneic asthma. A pilot study

INTRODUCTION

It has been demonstrated that brief periods of nocturnal continuous positive airway pressure (nCPAP) reduce airway reactivity in animal models and in patients with asthma. The effects of nCPAP in severe uncontrolled non-apneic asthmatic patients are not well known.

AIM

In this open pilot study, we aimed to assess the effect nCPAP on peak flow (PEF) variability and asthma control in this type of patients.

METHODS

CPAP was applied to 10 patients with severe long-standing asthma without obstructive sleep apnea for seven consecutive nights. CPAP was titrated in auto setting and applied to the patients. Daily PEF, was measured from 2 weeks before the intervention to 2 weeks after the end of nCPAP treatment. PEF amplitude and PEF morning dip (MD) over 24-h periods averaged over 1 week were calculated as indexes of PEF variability. Asthma control test (ACT) and European quality of life (EuroQol) questionnaire were measured at baseline and after 1 month, and at baseline and at the end of CPAP period, respectively.

RESULTS

The PEF amplitude significantly decreased both during CPAP period and in the first week after nCPAP discontinuation as compared with the baseline (19.8 ± 7.5%, 23.9 ± 9.1% and 28.9 ± 11.5%, respectively, always P < 0.05). PEF MD significantly decreased during nCPAP in comparison with the baseline (P < 0.001). The ACT and EuroQol significantly improved after nCPAP in comparison with the basal value.

CONCLUSIONS

In this preliminary report, brief period of nCPAP reduces PEF variability and improves control in severe non-apneic asthma at a short-term evaluation. Further studies with longer-term evaluation and larger number of patients are warranted.

Payer coverage for bronchial thermoplasty: shifting the traditional paradigm for refractory asthma therapy

The advent of bronchial thermoplasty (BT) provides a novel therapeutic option for asthma refractory to traditional medical therapy. Insurance coverage poses significant frustration for centers performing BT. Although clinical research has provided evidence of the usefulness and long-term safety of BT, establishing "reasonability and necessity" remains a daunting challenge in securing private and governmental insurance coverage. As a result, obtaining coverage poses significant frustration for centers capable of performing BT for patients suffering from severe asthma. Until recently, BT had been categorized by a temporary set of Current Procedural Terminology (CPT) codes as an emerging technology, service, or procedure (category 3). Based on increasing implementation of BT nationwide, the American Medical Association CPT Editorial Panel has assigned category 1 CPT codes for BT in their published 2013 professional edition. It is hoped that such a recommendation will reinforce the medical community's belief in the usefulness of BT and help facilitate decisions on insurance coverage. The ability to secure coverage for BT through physician advocacy and Centers for Medicare and Medicaid Services support will help move the treatment of refractory asthma forward.

Severe Asthma: The Evolution of Patient-directed Management

Severe asthma has been increasingly recognized as a heterogenous disease with varied clinical characteristics and pathophysiological processes. Patients with severe asthma suffer significant impairment in their daily life and impose a substantial burden on health care resources. The recent work of consortia groups has led to an improved definition of severe asthma as well as better characterization of the patients with severe disease. Different approaches, including unbiased cluster analyses, have been utilized to identify severe asthma phenotypes (subgroups) defined by their clinical characteristics and immune processes. Recognition of severe asthma phenotypes has assisted the development of targeted therapies by identifying patients more likely to respond to the specific agent. In this article, we discuss the evolution of our understanding of severe asthma and review the currently available therapies and promising drugs in development. In addition, we examine the role of bronchoscopy in severe asthma and the emerging evidence regarding bronchial thermoplasty.

Bronchial thermoplasty: interventional therapy in asthma

Bronchial thermoplasty is a new treatment option for patients with severe bronchial asthma who remain symptomatic despite maximal medical therapy. The aim of this interventional therapy option is the reduction of smooth muscle in the central and peripheral airways in order to reduce symptomatic bronchoconstriction via the application of heat. A full treatment with bronchial thermoplasty is divided into three bronchoscopies. Randomized, controlled clinical trials have shown an increase in quality of life, a reduction in severe exacerbations, and decreases in emergency department visits as well as days lost from school or work. The trials did not show a reduction in hyperresponsiveness or improvement in forced expiratory volume in 1 s. Short-term adverse effects include an increase in exacerbation rate, an increase in respiratory infections and an increase in hospitalizations. In the 5-year follow up of the studies available there was evidence of clinical and functional stability of the treated patients. Further studies are necessary to identify an asthma phenotype that responds well to this treatment.

EAACI position statement on asthma exacerbations and severe asthma

Asthma exacerbations and severe asthma are linked with high morbidity, significant mortality and high treatment costs. Recurrent asthma exacerbations cause a decline in lung function and, in childhood, are linked to development of persistent asthma. This position paper, from the European Academy of Allergy and Clinical Immunology, highlights the shortcomings of current treatment guidelines for patients suffering from frequent asthma exacerbations and those with difficult‐to‐treat asthma and severe treatment‐resistant asthma. It reviews current evidence that supports a call for increased awareness of (i) the seriousness of asthma exacerbations and (ii) the need for novel treatment strategies in specific forms of severe treatment‐resistant asthma. There is strong evidence linking asthma exacerbations with viral airway infection and underlying deficiencies in innate immunity and evidence of a synergism between viral infection and allergic mechanisms in increasing risk of exacerbations. Nonadherence to prescribed medication has been identified as a common clinical problem amongst adults and children with difficult‐to‐control asthma. Appropriate diagnosis, assessment of adherence and other potentially modifiable factors (such as passive or active smoking, ongoing allergen exposure, psychosocial factors) have to be a priority in clinical assessment of all patients with difficult‐to‐control asthma. Further studies with improved designs and new diagnostic tools are needed to properly characterize (i) the pathophysiology and risk of asthma exacerbations, and (ii) the clinical and pathophysiological heterogeneity of severe asthma.

Asthma

Asthma is a heterogeneous group of conditions that result in recurrent, reversible bronchial obstruction. Although the disease can start at any age, the first symptoms occur during childhood in most cases. Asthma has a strong genetic component, and genome-wide association studies have identified variations in several genes that slightly increase the risk of disease. Asthma is often associated with increased susceptibility to infection with rhinoviruses and with changes in the composition of microbial communities colonising the airways, but whether these changes are a cause or consequence of the disease is unknown. There is currently no proven prevention strategy; however, the finding that exposure to microbial products in early life, particularly in farming environments, seems to be protective against asthma offers hope that surrogates of such exposure could be used to prevent the disease. Genetic and immunological studies point to defective responses of lung resident cells, especially those associated with the mucosal epithelium, as crucial elements in the pathogenesis of asthma. Inhaled corticosteroids continue to be the mainstay for the treatment of mild and moderate asthma, but limited adherence to daily inhaled medication is a major obstacle to the success of such therapy. Severe asthma that is refractory to usual treatment continues to be a challenge, but new biological therapies, such as humanised antibodies against IgE, interleukin 5, and interleukin 13, offer hope to improve the quality of life and long-term prognosis of severe asthmatics with specific molecular phenotypes.

Bronchial thermoplasty

Bronchial thermoplasty is a relatively new therapy for the management of severe asthma. It involves the direct bronchoscopic application of thermal energy to airways by a catheter-directed expandable basket. The airways of the lower and upper lobes are treated in 3 separate sessions spaced 3 weeks apart. The therapy targets airway smooth muscle, with studies showing a decrease in airway smooth muscle after bronchial thermoplasty therapy. After therapy, an improvement in quality of life and decrease in asthma exacerbations can be expected. Adverse events can occur with bronchial thermoplasty and careful patient selection is critical to ensure benefits outweigh the potential risks.

Advances and future directions in interventional pulmonology

The term "interventional pulmonology" (IP) supersedes the previously used term "thoracic endoscopy," a change that reflects the evolution of a specialty devoted to performing highly sophisticated and technologically advanced procedures in the lungs and chest. Continuing advances in technology promise to further expand IP's diagnostic and therapeutic frontiers. However, standardized educational programs to train and test IP physicians will be essential to maintain a high standard of practice in the field.

Bronchial thermoplasty failure in severe persistent asthma: a case report

INTRODUCTION

Bronchial thermoplasty (BT) is an emerging therapy for patients with severe persistent asthma who remain poorly controlled despite standard maximal medical therapy. Thermoplasty elicits asthma control over time by applying thermal radiofrequency energy to airways to ablate underlying smooth muscle. While this therapy is suggested to eliminate such smooth muscle permanently, no human studies have examined the possibility of treatment failure.

CASE REPORT

We present a 62-year-old female with severe, refractory asthma symptoms who underwent BT without apparent complications. However, severe symptoms including multiple clinical exacerbations persisted despite BT treatment. Repeat endobronchial biopsy done six months after BT treatment demonstrated persistent smooth muscle hyperplasia in multiple airways that previously had been treated. The patient continued to have uncontrolled, refractory asthma despite multiple therapies.

CONCLUSION

This case is the first to describe a failure of BT to reduce or eliminate airway smooth muscle in a patient with severe persistent asthma. It suggests the potential for treatment failure in the management of these patients after BT and highlights the need for further study of potential BT-refractory patients.

Latest advances in advanced diagnostic and therapeutic pulmonary procedures

Over the past 15 years, patients with a myriad of pulmonary conditions have been diagnosed and treated with new technologies developed for the pulmonary community. Advanced diagnostic and therapeutic procedures once performed in an operating theater under general anesthesia are now routinely performed in a bronchoscopy suite under moderate sedation with clinically meaningful improvements in outcome. With the miniaturization of scopes and instruments, improvements in optics, and creative engineers, a host of new devices has become available for clinical testing and use. A growing community of pulmonologists is doing comparative effectiveness trials that test new technologies against the current standard of care. While more research is needed, it seems reasonable to provide an overview of pulmonary procedures that are in various stages of development, testing, and practice at this time. Five areas are covered: navigational bronchoscopy, endobronchial ultrasound, endoscopic lung volume reduction, bronchial thermoplasty, and pleural procedure. Appropriate training for clinicians who wish to provide these services will become an area of intense scrutiny as new skills will need to be acquired to ensure patient safety and a good clinical result.

Anti-inflammatory dimethylfumarate: a potential new therapy for asthma?

Asthma is a chronic inflammatory disease of the airways, which results from the deregulated interaction of inflammatory cells and tissue forming cells. Beside the derangement of the epithelial cell layer, the most prominent tissue pathology of the asthmatic lung is the hypertrophy and hyperplasia of the airway smooth muscle cell (ASMC) bundles, which actively contributes to airway inflammation and remodeling. ASMCs of asthma patients secrete proinflammatory chemokines CXCL10, CCL11, and RANTES which attract immune cells into the airways and may thereby initiate inflammation. None of the available asthma drugs cures the disease—only symptoms are controlled. Dimethylfumarate (DMF) is used as an anti-inflammatory drug in psoriasis and showed promising results in phase III clinical studies in multiple sclerosis patients. In regard to asthma therapy, DMF has been anecdotally reported to reduce asthma symptoms in patients with psoriasis and asthma. Here we discuss the potential use of DMF as a novel therapy in asthma on the basis of in vitro studies of its inhibitory effect on ASMC proliferation and cytokine secretion in ASMCs.

Sputum mediator profiling and relationship to airway wall geometry imaging in severe asthma

Background

Severe asthma is a heterogeneous disease and the relationship between airway inflammation and airway remodelling is poorly understood. We sought to define sputum mediator profiles in severe asthmatics categorised by CT-determined airway geometry and sputum differential cell counts.

Methods

In a single centre cross-sectional observational study we recruited 59 subjects with severe asthma that underwent sputum induction and thoracic CT. Quantitative CT analysis of the apical segment of the right upper lobe (RB1) was performed. Forty-one mediators in sputum samples were measured of which 21 mediators that were assessable in >50% of samples were included in the analyses.

Results

Independent of airway geometry, sputum MMP9 and IL-1β were elevated in those groups with a high sputum neutrophil count while sputum ICAM was elevated in those subjects with a low sputum neutrophil count. In contrast, sputum CCL11, IL-1α and fibrinogen were different in groups stratified by both sputum neutrophil count and airway geometry. Sputum CCL11 concentration was elevated in subjects with a low sputum neutrophil count and high luminal and total RB1 area, whereas sputum IL1α was increased in subjects with a high sputum neutrophil count and low total RB1 area. Sputum fibrinogen was elevated in those subjects with RB1 luminal narrowing and in those subjects with neutrophilic inflammation without luminal narrowing.

Conclusions

We have demonstrated that sputum mediator profiling reveals a number of associations with airway geometry. Whether these findings reflect important biological phenotypes that might inform stratified medicine approaches requires further investigation.

Airway smooth muscle in the pathophysiology and treatment of asthma

Airway smooth muscle (ASM) plays an integral part in the pathophysiology of asthma. It is responsible for acute bronchoconstriction, which is potentiated by constrictor hyperresponsiveness, impaired relaxation and length adaptation. ASM also contributes to airway remodeling and inflammation in asthma. In light of this, ASM is an important target in the treatment of asthma.

Redefining approaches to asthma: developing targeted biologic therapies

Asthma is a chronic respiratory disorder canonically associated with type 2 airway inflammation as characterized by elevated levels of eosinophils, immunoglobulin E, and cytokines including interleukin (IL) 4, IL5, IL9, and IL13 and tumor necrosis factor (TNF) α. However, mounting evidence has shown that considerable heterogeneity exists in human asthma in terms of the nature and intensity of airway inflammation. While many asthma patients achieve acceptable control of symptoms with standard-of-care therapies such as β₂-adrenergic agonists and inhaled corticosteroids, a minority remains symptomatic despite maximal standard-of-care therapy and constitutes a significant unmet medical need. A growing number of investigational therapeutics under clinical development for asthma are biologic therapies that specifically target mediators of type 2 airway inflammation. In this chapter, we consider the biological functions of therapeutic targets in asthma and data from clinical trials of biologic agents directed against these targets. We discuss recent clinical trial results in terms of four key components of drug development: target selection, molecule selection, outcome selection, and patient selection, with particular attention paid to the emerging role of biomarkers in clinical development for asthma.

Safety and feasibility of bronchial thermoplasty in asthma patients with very severe fixed airflow obstruction: a case series

OBJECTIVE

Bronchial thermoplasty (BT) can provide relief for patients with severe, uncontrolled asthma despite maximal medical therapy. However, it is unclear whether BT is safe in patients with very severe airflow obstruction.

METHODS

We performed BT in eight patients with severe asthma as defined by Expert Panel Report 3 (EPR-3) guidelines who were poorly controlled despite step 5 therapy. Data were available on each subject for 1 year prior to and 15-72 weeks following BT.

RESULTS

The mean (±SEM) pre-bronchodilator forced expiratory volume in one second (FEV(1)) prior to BT was 51.8 ± 8.6% of predicted, and the mean (±SEM) number of hospitalizations for asthma in the year prior to BT was 2.9 ± 1.2. No subject had an unexpected severe adverse event due to BT. Among the eight patients with follow-up of at least 15 weeks, there was no significant decline in FEV(1) (p = .4).

CONCLUSION

We suggest that BT may be safe for asthma patients with severe airflow obstruction and higher hospitalization rates than previously reported.

Severe asthma in adults: an orphan disease?

Severe asthma affects fewer than 10% of patients with asthma, is associated with a severe risk of death and disability, has a great impact on health and quality of life, and represents a huge cost to patients and society. Given the poor response to treatment and the side effects associated with medications for severe asthma, more efficient, cost-effective, and phenotype-specific medications are needed. Considering severe asthma as an orphan disease could encourage the pharmaceutical industry to stratify studies based on a more detailed characterization of study subjects at baseline, resulting in the development of novel therapeutic approaches.