Tracheal section is an independent predictor of asthma in patients with nasal polyposis

Chronic Rhinosinusitis with Nasal Polyps and Asthma

Patients with chronic rhinosinusitis with nasal polyps (CRSwNP) characterized by a type 2 immune signature often have severe and recurrent disease. Lower airway conditions such as asthma are common comorbidities and share similar pathophysiology. CRSwNP with asthma is characterized by tissue eosinophilia and high local IgE levels. Clinically, CRSwNP with comorbid asthma is associated with more severe sinonasal symptoms and worse quality of life, and it is more difficult to treat both medically and surgically. Asthma in the presence of nasal polyposis is also more difficult to control, being more exacerbation prone, with increased airway obstruction and more extensive eosinophilic inflammation. Aspirin/nonsteroidal anti-inflammatory drug-exacerbated respiratory disease (AERD) is a recognized phenotype of CRSwNP with comorbid asthma. Patients with CRSwNP with comorbid AERD are among those with the most severe and difficult-to-treat disease, and tend to have severe NP. The shared pathophysiology of the upper and lower airways has important implications for both the diagnosis and management of respiratory comorbidities. However, in clinical practice, the nose and lungs are often treated as separate entities. The underlying systemic inflammatory link between CRSwNP and asthma provides a compelling rationale for systemic treatment with novel biologics targeting shared underlying type 2 inflammatory pathways.

Clinical Phenotypes of Nasal Polyps and Comorbid Asthma Based on Cluster Analysis of Disease History

BACKGROUND

Nasal polyps and comorbid asthma (NPcA) is a common united airway disease and is highly heterogeneous with respect to clinical, physiologic, and pathologic parameters. The clinical phenotypes of NPcA are poorly understood.

OBJECTIVE

We sought to explore clinical phenotypes in patients with NPcA.

METHODS

Patients first diagnosed with NPcA were recruited from Rhinological Clinics and Respiratory Clinics. We clustered patients with NPcA based on parameters regarding natural courses and demographic characteristics. Patients were also evaluated with respect to clinical, functional, and inflammatory parameters in both upper and lower airways.

RESULTS

Clustering of 110 cases resulted in 3 clusters: cluster 1 (n = 16, 14.55%, atopic NPcA) was predominantly atopic patients with child-onset airway symptoms, intermediate disease duration, history of family asthma, better lung function, and less severe asthma; cluster 2 (n = 32, 29.09%, smoking NPcA) was characterized by more smokers, short disease duration, adult-onset airway symptoms, less atopy, nonsteroidal anti-inflammatory drug sensitivity, prior sinus surgery history, eosinophilic airway phenotypes, worse lung function, and severe computed tomography appearance; and cluster 3 (n = 62, 56.36%, older NPcA) consisted mostly of older patients with long disease duration, adult-onset airway symptoms, less atopy, more noneosinophilic airway phenotypes, and prior sinus surgery history.

CONCLUSIONS

Patients with NPcA with 3 distinct natural courses had different inflammatory status and disease severity. Determining the natural course of a patient might help clinicians predict the clinical aspects of NPcA and contribute to phenotype-guided management approaches in the future.

Methacholine-Induced Variations in Airway Volume and the Slope of the Alveolar Capnogram Are Distinctly Associated with Airflow Limitation and Airway Closure

Mechanisms driving alteration of lung function in response to inhalation of a methacholine aerosol are incompletely understood. To explore to what extent large and small airways contribute to airflow limitation and airway closure in this context, volumetric capnography was performed before (n = 93) and after (n = 78) methacholine provocation in subjects with an intermediate clinical probability of asthma. Anatomical dead space (VDaw), reflecting large airway volume, and the slope of the alveolar capnogram (slope3), an index of ventilation heterogeneity linked to small airway dysfunction, were determined. At baseline, VDaw was positively correlated with lung volumes, FEV₁ and peak expiratory flow, while slope3 was not correlated with any lung function index. Variations in VDaw and slope3 following methacholine stimulation were correlated to a small degree (R² = -0.20). Multivariate regression analysis identified independent associations between variation in FEV₁ and variations in both VDaw (Standardized Coefficient-SC = 0.66) and Slope3 (SC = 0.35). By contrast, variation in FVC was strongly associated with variations in VDaw (SC = 0.8) but not Slope3. Thus, alterations in the geometry and/or function of large and small airways were weakly correlated and contributed distinctly to airflow limitation. While both large and small airways contributed to airflow limitation as assessed by FEV1, airway closure as assessed by FVC reduction mostly involved the large airways.