Clinical Deterioration and Lung Function Change in Patients With Concomitant Asthma and Bronchiectasis

Proposed Etiotypes for Chronic Obstructive Pulmonary Disease: Controversial Issues

The 2023 Global Initiative for Chronic Obstructive Lung Disease (GOLD) revised the definition of chronic obstructive pulmonary disease (COPD) to broadly include a variety of etiologies. A new taxonomy, composed of etiotypes, aims to highlight the heterogeneity in causes and pathogenesis of COPD, allowing more personalized management strategies and emphasizing the need for targeted research to understand and manage COPD better. However, controversy arises with including some diseases under the umbrella term of COPD, as their clinical presentations and treatments differ from classical COPD, which is smoking-related. COPD due to infection (COPD-I) and COPD due to environmental exposure (COPD-P) are classifications within the new taxonomy. Some disease entities in these categories show distinct clinical features and may not benefit from conventional COPD treatments, raising questions about their classification as COPD subtypes. There is also controversy regarding whether bronchiectasis with airflow limitations should be classified as an etiotype of COPD. This article discusses controversial issues associated with the proposed etiotypes for COPD in terms of COPD-I, COPD-P, and bronchiectasis. While the updated COPD definition by GOLD 2023 is a major step towards recognizing the disease's complexity, it also raises questions about the classification of related respiratory conditions. This highlights the need for further research to improve our understanding and approach to COPD management.

The Impact of Bronchiectasis on the Clinical Characteristics of Non-Severe Asthma

Current literature primarily delves into the relationship between bronchiectasis and severe asthma, and only a few studies have evaluated the impact of bronchiectasis in patients with non-severe asthma. Therefore, this study investigated the clinical impact of bronchiectasis in patients with non-severe asthma. A prospective observational study of 140 non-severe asthmatic patients with (bronchiectasis group) and without bronchiectasis (control group) was conducted between September 2012 and February 2022. The bronchiectasis and control groups were compared in terms of demographics, lung function, asthma control test (ACT) results, exacerbation history, and respiratory medications. Among 140 non-severe asthmatic subjects, approximately 15.7% (n = 22) had bronchiectasis. The most common type of bronchiectasis was cylindrical type (90.7%). The left lingular division was the most frequently involved lung lobe (20.4%). There were no significant differences in the demographics (age, sex, body mass index, smoking history, and comorbidities) or ACT results between the 2 groups. The bronchiectasis group used inhaled corticosteroids/long-acting β2-agonists (P = 0.074) and mucolytics (P < 0.001) more frequently than the control group. Compared to the control group, the bronchiectasis group had lower forced expiratory volume in 1 second (FEV1) (L) (1.9 ± 0.7 L vs. 2.3 ± 0.9 L, P = 0.039) and FEV1%predicted (67.2 ± 22.2%predicted vs. 77.1 ± 20.0%predicted, P = 0.038). The rate of hospital admission to a general ward in the preceding year was significantly higher in the bronchiectasis group compared to those of the control group (23.8% vs. 3.5%, P = 0.005) with an adjusted odds ratio of 6.308 (95% confidence interval, 1.401-28.392). Patients with non-severe asthma and bronchiectasis had lower lung function and more frequent exacerbations requiring hospitalization than those without bronchiectasis. More attention is needed for asthmatic patients with bronchiectasis, even if the asthma is not severe.

Preparation of Budesonide-Loaded Liposomal Nanoparticles for Pulmonary Delivery and Their Therapeutic Effect in OVA-Induced Asthma in Mice

Purpose

Inhaled corticosteroids, including budesonide (BUD), are widely employed for the treatment of asthma. However, the frequent use of corticosteroids is associated with numerous adverse effects and poses challenges to ongoing drug therapy and patient adherence. Budesonide liposomal nanoparticles (BUD-LNPs) were developed to improve the bioavailability of the drug and thereby improve the effectiveness of asthma treatment.

Methods

BUD-LNPs were prepared via thin-film hydration, and the characterizations, stability, and in vitro release of BUD-LNPs were studied. In vitro cellular uptake was observed by laser-scanning confocal microscope (LSCM) and flow cytometry. And the in vitro anti-inflammatory activity of BUD-LNPs was evaluated by measuring the expression of pro-inflammatory cytokines in activated macrophages. Besides, the accumulation time in the lung of drugs delivered via liposomal carriers and free drugs was compared in vivo. And the in vivo therapeutic efficacy of BUD-LNPs was assessed in OVA-induced asthmatic mice. Finally, in vivo biosafety assessment was performed.

Results

The particle size, PDI, and zeta potential of BUD-LNPs were 127.63±1.33 nm, 0.27±0.02, and 3.33±0.13 mV, respectively. BUD-LNPs exhibited excellent biosafety and anti-inflammatory activity in vitro. Furthermore, compared with the free drugs, the utilization of liposomal nano-vehicles for drugs delivery could effectively extend the duration of drugs accumulation in the pulmonary system. Additionally, treatment with BUD-LNPs alleviated airway hyperresponsiveness, reduced airway mucus secretion, and mitigated pulmonary inflammation in OVA-induced asthmatic mice. And the BUD-LNPs demonstrated superior therapeutic efficacy compared to free BUD.

Conclusion

BUD-LNPs was successfully prepared with excellent stability and sustained release for 24 h in vitro. The data of anti-inflammatory activity, asthma therapeutic effects and safety studies indicated that drug delivery mediated by liposomal nano-vehicles was a feasible and desirable strategy for medical strategy and showed great promise in the clinical therapy of asthma.

Bacteria and viruses and clinical outcomes of asthma-bronchiectasis overlap syndrome: A cohort study

BACKGROUND

Despite the high prevalence of co-existing bronchiectasis and asthma (asthma-bronchiectasis overlap syndrome [ABOS]), little is known regarding the dominant pathogens and clinical correlates.

OBJECTIVE

To investigate the bacteria and viruses which differentially dominate in ABOS (including its subtypes) compared with bronchiectasis alone, and determine their relevance with bronchiectasis severity and exacerbations.

METHODS

This was a prospective observational cohort study conducted between March 2017 and August 2023. We included 81 patients with ABOS and 107 patients with bronchiectasis alone. At steady-state baseline, patients underwent comprehensive assessments and sputum collection for bacterial culture and viral detection (quantitative polymerase-chain-reaction). Patients were followed-up to record exacerbation and spirometry.

RESULTS

Patients with ABOS had significantly higher symptom burden and exacerbation frequency than those with bronchiectasis alone. Despite similar pathogen spectrum, the rate of bacteria-virus co-detection increased less substantially at acute exacerbations (AE) onset than at steady-state compared with bronchiectasis alone. Pathogenic bacteria (particularly Pseudomonas aeruginosa) were detected fairly common (exceeding 50%) in ABOS and were associated with greater severity of bronchiectasis when stable and conferred greater exacerbation risks at follow-up. Viral but not bacterial compositions changed substantially at AE onset compared with clinical stability. Higher blood eosinophil count, moderate-to-severe bronchiectasis and non-atopy were associated with higher odds of bacterial, but not viral, detection (all p < 0.05).

CONCLUSION

Detection of bacteria or virus is associated with bronchiectasis severity or clinical outcomes in ABOS. This highlights the importance of integrating sputum microbial assessment for ascertaining the dominant pathophysiology (atopy vs. infection) and longitudinal trajectory prediction in ABOS.

Does asthma-bronchiectasis overlap syndrome (ABOS) really exist?

OBJECTIVE

To analyze the relationship between asthma and bronchiectasis, as well as the necessary conditions that this connection must meet for this group of patients to be considered a special phenotype.

DATA SOURCES

We performed a PubMed search using the MeSH terms "asthma" and "bronchiectasis." The literature research was limited to clinical trials, meta-analyses, randomized controlled trials, cohort studies, and systematic reviews, involving adult patients, published until November 30th, 2022.

STUDY SELECTIONS

Selected papers were initially evaluated by the Authors, to assess their eligibility in contributing to the statements.

RESULTS

The prevalence of bronchiectasis is higher than expected in patients with asthma, particularly in those with more severe disease, and in some patients, between 1.4% and 7% of them, asthma alone could be the cause of bronchiectasis. Both diseases share etiopathogenic mechanisms, such as neutrophilic and eosinophilic inflammation, altered airway microbiota, mucus hypersecretion, allergen sensitization, immune dysfunction, altered microRNA, dysfunctional neutrophilic activity, and variants of the HLA system. Besides that, they also share comorbidities, such as gastroesophageal reflux disease and psychiatric illnesses. The clinical presentation of asthma is very similar to patients with bronchiectasis, which could cause mistakes with diagnoses and delays in being prescribed the correct treatment. The coexistence of asthma and bronchiectasis also poses difficulties for the therapeutic focus.

CONCLUSIONS

The evidence available seems to support that the asthma-bronchiectasis phenotype really exists although longitudinal studies which consistently demonstrate that asthma is the cause of bronchiectasis are still lacking.