Airway and Systemic Immunoglobulin Profiling and Immune Response in Adult Asthma.

INTRODUCTION: Immunoglobulins play a vital role in host immune response and in the pathogenesis of conditions like asthma. Therapeutic agents such as monoclonal antibodies target specific elements of the asthmatic inflammatory cascade. Decisions to utilize these medications are often based on systemic inflammatory profiling without direct insight into the airway inflammatory profile. We sought to investigate the relationship between immunoglobulin and cytokine profiles in the airway and systemic immune compartments of adult asthmatics. METHODS: Blood sampling and bronchoscopy with bronchoalveolar lavage (BAL) were performed in 76 well-defined adult asthmatics. Antibody and cytokine profiles were measured in both BAL and serum using ELISA and quantibody arrays. RESULTS: There was no relationship between BAL and serum levels of IgE. This is of significance in an asthma population. For some analytes, correlation analysis was significant (P < 0.05) indicating representativeness of our cohort and experimental setup in those cases. Nevertheless, the predictive power (r2) of the BAL-to-serum comparisons was mostly low except for TNF-α (r2 = 0.73) when assuming a simple (linear) relationship. CONCLUSION: This study highlights the importance of sample site when investigating the roles of immunoglobulins and cytokines in disease pathogenesis and suggests that both localized and systemic immune responses are at play. The prescription of asthma monoclonal therapy is generally based on systemic evaluation of cytokine and immunoglobulin levels. Our research suggests that this approach may not fully reflect the pathophysiology of the disease and may provide insight into why some patients respond to these targeted therapies while others do not.

Impact of Airway Virus in Severe Asthmatic Patients: A Pilot Study.

The lungs have their own microbiota which seems to be altered in disease processes such as asthma. Viral infection accounts for many asthma exacerbations. Little is known about the lung virome, and the role that viruses play in non-exacerbating asthmatics. We aimed to assess if detection of virus in bronchoscopy samples of asthmatic patients in a non-exacerbating state influences their asthma control and modulates airway cytokine composition. Patients were recruited from a specialist asthma clinic and underwent bronchoscopy with standardised bronchoalveolar lavage (BAL). Viral analysis was performed; cell differential and cytokine levels were measured. Forty-six samples were obtained of which 10.8% demonstrated evidence of airway virus, and 91.3% of patients in the cohort were classed as severe asthmatics. Oral steroid use was significantly higher in severe asthmatic patients with virus detected, and the forced expiratory volume in one second tended to be lower in the virus-detected group. It was also found that BAL interleukin-13 and tumor necrosis factor-α levels were significantly higher in severe asthmatic patients with virus detected. Our results suggest that in severe asthmatics in a non-exacerbating state, the presence of virus resulted in overall poorer asthma control. The pattern of cytokine elevation seen in asthmatic patients with virus detected may provide insight to the pathophysiology involved.

Environmental influences on childhood asthma-The effect of diet and microbiome on asthma.

Early life dietary patterns and timely maturation of mucosa-associated microbial communities are important factors influencing immune development and for establishing robust immune tolerance networks. Microbial fermentation of dietary components in vivo generates a vast array of molecules, some of which are integral components of the molecular circuitry that regulates immune and metabolic functions. These in turn protect against aberrant inflammatory processes and promote effector immune responses that quickly eliminate pathogens. Multiple studies suggest that changes in dietary habits, altered microbiome composition, and microbial metabolism are associated with asthma risk and disease severity. While it remains unclear whether these microbiome alterations are a cause or consequence of dysregulated immune responses, there is significant potential for using diet in targeted manipulations of the gut microbiome and its metabolic functions in promoting immune health. In this article, we will summarize our knowledge to date on the role of dietary patterns and microbiome activities on immune responses within the airways. Given the malleability of the human microbiome, its integration into the immune system, and its responsiveness to diet, this makes it a highly attractive target for therapeutic and nutritional intervention in children with asthma.

Real-World clinical outcomes of asthma patients switched from reslizumab to mepolizumab or benralizumab.

Introduction: Approximately 3%-10% of asthma patients will remain uncontrolled despite maximum, optimal conventional therapy. Treatment of severe refractory asthma often involves the use of targeted biological therapy. Randomised controlled trials have shown improvements in clinical parameters with these treatments but real-world data is lacking. Methods: The clinical parameters, frequency of exacerbations, number of hospital admissions, asthma control questionnaire score (ACQ), forced expiratory volume in one second (FEV1) and maintenance oral corticosteroid (OCS) dose of twenty asthma patients switched from reslizumab to benralizumab or mepolizumab at 1 year prior and 6 months after switching were compared, with adjustments for time. Results: The mean frequency of exacerbations (0.35 v 0.3) and the mean ACQ were essentially unchanged (1.6 v 1.5) following the switch. The number of hospital admissions was one in the 6 months post switch compared to one in 1-year pre switch. 25% of patients were on maintenance OCS before and after switching but one patient required an increased dose post switch resulting in an increase in the mean maintenance OCS dose (1.6 mg to 2.4 mg). The mean FEV1 was unchanged (80% v 77.9%) six months post switching. Regarding asthma control (n = 19), 47.4% were controlled pre and post switch (ACQ < 1.5), 36.8% remained uncontrolled despite switching, 10.5% improved control while 5.3% disimproved. Conclusion: We present real-world clinical outcomes of asthma patients switched from reslizumab to either benralizumab or mepolizumab without a loss of clinical effectiveness in the majority.

Use of non-invasive ventilation in motor neuron disease - a retrospective cohort analysis.

Motor neuron disease (MND) is a neurodegenerative disorder which leads to progressive muscle weakness including respiratory muscle decline. The introduction of non-invasive ventilation (NIV) has been shown to improve quality of life, survival and slow the rate of pulmonary function decline. A retrospective chart analysis of patients who attended the MND clinic from 2014 to 2019 at a tertiary-referral, academic, teaching hospital was carried out to evaluate if NIV and greater compliance with NIV was associated with improved survival. 111 patients were included. The mean age at diagnosis was 63.8 years and 61.3% were males. 66.7% of our cohort used NIV and of this 66.7%, 44.1% were compliant. There was a significantly longer survival in those who used NIV (p = 0.002) and in those who used NIV optimally (p = 0.02) when both groups were compared to those who did not use NIV. In the bulbar MND group those who were compliant with NIV survived longer than who those who did not use NIV (p = 0.001). We found a significantly longer survival with the use of NIV, the use of NIV optimally and with use of NIV in those with bulbar onset MND compared to those who did not use NIV.

Endobronchial Balloon Blockers: A Retrospective Analysis of Their Implementation for Use in Transbronchial Cryobiopsy Under Conscious Sedation.

INTRODUCTION: Transbronchial lung cryobiopsy (TBLC) is a promising technique that is evolving as a standard diagnostic procedure in the diagnosis of interstitial lung disease. However, there are a variety of non-standardised techniques adopted for this procedure. We aim to describe our approach to TBLC with balloon blockade under conscious sedation (CS). METHODS: We performed a retrospective analysis of patients undergoing TBLC using flexible bronchoscopy under CS in our institution over the calendar years 2017-2018; before and after a transition to the use of endobronchial balloon blockers (EBB) in 2017. RESULTS: 25 patients underwent transbronchial cryobiopsy during the study period. Of these; 12 procedures used EBB. EBB subjects had significantly less moderate or severe airway bleeding (8.3% vs 38.5%) despite higher biopsy rates in the EBB group, 2.9 (2-4) vs 2.4 (1-4) in the non-EBB group. No severe airway bleeding occurred in the EBB group. A multidisciplinary meeting (MDM) confirmed diagnosis was achieved in 88% of patients. 10/12 subjects (83%) in the EBB group and 12/13 subjects (92%) in the non-EBB group (p = 0.5). CONCLUSION: Our institution is novel in using EBB as standard during TBLC specifically under CS with flexible bronchoscopy in the bronchoscopy suite. This retrospective analysis demonstrates that EBB enhances the safety profile of performing TBLC under CS and did not appear to impact diagnostic yield or patient safety.

The Benefit of Non-invasive Ventilation in Motor Neuron Disease.

BACKGROUND: Motor Neuron Disease (MND) is a progressive neurodegenerative disorder leading to respiratory muscle weakness with dyspnoea, morning headaches, orthopnoea, poor concentration, unrefreshing sleep, fatigue and daytime somnolence. Respiratory failure is the primary cause of death in those with MND. METHODS: Although guidelines suggest the use of non-invasive ventilation (NIV) in MND, there lacks clear guidance as to when is the optimal time to initiate NIV and which markers of respiratory muscle decline are the best predictors of prognosis. There have been a number of studies that have found a significant survival advantage to the use of NIV in MND. Similarly, in quality-of-life questionnaires, those treated with NIV tend to perform better and maintain a better quality of life for longer. Furthermore, studies also suggest that improved compliance and greater tolerance of NIV confer a survival advantage. RESULTS AND DISCUSSION: Forced Vital Capacity (FVC) has traditionally been the main pulmonary function test to determine the respiratory function in those with MND; however, FVC may not be entirely reflective of early respiratory muscle dysfunction. Evidence suggests that sniff nasal inspiratory pressure and maximum mouth inspiratory pressure may be better indicators of early respiratory muscle decline. These measures have been shown to be easier to perform later in the disease, in patients with bulbar onset disease, and may indeed be better prognostic indicators. CONCLUSION: Despite ongoing research, there remains a paucity of randomised controlled data in this area. This review aims to summarise the evidence to date on these topics.