Mixed cell type in airway inflammation is the dominant phenotype in asthma patients with severe chronic rhinosinusitis

Non-Type 2 and Mixed Inflammation in Chronic Rhinosinusitis and Lower Airway Disease

OBJECTIVE

The aim was to discuss the role of non-type 2 inflammation in patients diagnosed with chronic rhinosinusitis (CRS) and comorbid lower airway disease.

DATA SOURCES

Medline, Embase, National Institute for Health and Care Excellence, TRIP Database, ProQuest, Clinicaltrials.gov, Cochrane Central Registry of Controlled Trials, Web of Science, government and health organizations, and graduate-level theses.

REVIEW METHODS

This scoping review followed PRISMA-ScR guidelines. Search strategy was peer-reviewed by medical librarians. Studies were included if they utilized airway sampling, non-type 2 cytokines, and patients with CRS and lower airway disease.

RESULTS

Twenty-seven from 7060 articles were included. In patients with CRS and comorbid asthma, aspirin-exacerbated respiratory disease (AERD), and chronic obstructive pulmonary disease (COPD)/bronchiectasis, 60% (n = 12), 33% (n = 2), and 100% (n = 1), respectively, demonstrated mixed or non-type 2 endotypes. Comorbid CRS and asthma produced type 1 (n = 1.5), type 2 (n = 8), type 3 (n = 1), mixed type 1/2 (n = 1), and mixed type 1/2/3 (n = 8.5) endotype shifts. AERD demonstrated type 2 (n = 4), mixed type 2/3 (n = 1), and mixed type 1/2/3 (n = 1) endotype shifts. CRS with COPD or bronchiectasis demonstrated a mixed 1/2 (n = 1) endotype shift.

CONCLUSION

Type 2 disease has been extensively reviewed due to advent biologics targeting type 2 inflammation, but outcomes may be suboptimal due to the presence of non-type 2 inflammation. A proportion of patients with CRS and comorbid lower airway disease demonstrated mixed and non-type 2 endotype shifts. This emphasizes that patients with unified airway disease may have forms of inflammation beyond classical type 2 disease which could inform biologic development. Laryngoscope, 134:1005-1013, 2024.

Sputum microbiota and inflammatory subtypes in asthma, COPD, and its overlap

Background

Airway microbiota in asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) remains unknown.

Objective

This study with ACO-enriched population aimed to clarify airway microbiota in ACO and in mixed granulocytic inflammation, often detected in ACO and chronic airway diseases.

Methods

This is an observational cross-sectional study. Patients with asthma with airflow limitation, ACO, and COPD were enrolled. Blood tests, pulmonary function, exhaled nitric oxide, and sputum tests were conducted. Sputum microbiota was evaluated using the 16S rRNA gene sequencing technique.

Results

A total of 112 patients (13 asthma, 67 ACO, and 32 COPD) were examined. There were no significant differences in α-diversity among the 3 diseases. The relative abundances of phylum Bacteroidetes, class Bacteroidia, and genus Porphyromonas were associated with decreased eosinophilic inflammation, and were significantly lower in ACO than in COPD. In a comparison of sputum inflammatory subtypes, the proportion of Haemophilus was numerically highest in the mixed granulocytic subtype, followed by the neutrophilic subtype. Likewise, the proportion of Haemophilus was the highest in the intermediate-high (2%-8%) sputum eosinophil group and lowest in the severe (≥8%) eosinophil group. Clinically, Haemophilus proportion was associated with sputum symptoms. Finally, the proportion of Streptococcus was associated with higher blood eosinophil counts and most severe airflow limitation.

Conclusions

Bacteroidia and Porphyromonas abundances in sputum are associated with the eosinophil-low phenotype, and ACO may be characterized by a decrease in these taxa. A mild elevation in sputum eosinophil does not preclude the presence of Haemophilus, which should be noted in the management of obstructive airway diseases.

Using induced sputum method in clinical practice in patients with bronchial asthma

This article presents an overview of modern statements of the induced sputum method; detailed description of the methods and protocols for taking sputum in adults and children, methods for processing the obtained substance. The paper describes in detail the features of the cellular composition of induced sputum in healthy individuals and in patients with bronchial asthma, emphasizes the importance of the eosinophilia level as a prognostic and diagnostic criterion of asthma and also determines the functions of other induced sputum cells such as neutrophils, macrophages, basophils. The article is illustrated with photographs of sputum microscopy. In addition to sputum cytology, we give accent to the possibility of using other research methods such as an identification of viral and bacterial pathogens, genomics, proteomics, lipidomics, metabolomics, determination of the concentration of various mediators in the sputum supernatant. The paper presents the ideas on biochemical inflammatory markers and remodelling of the respiratory tract in asthma, which can be determined in sputum (C3a anaphylatoxin, clusterin, periostin, eosinophil-derived neurotoxin, folliculin). In addition, we summarize the information on inflammatory phenotypes of bronchial asthma, emphasize their variability and modification depending on the period of the disease, prescribed treatment, intercurrent respiratory infections, and smoking. The article also presents detailed characteristics of eosinophilic, neutrophilic, mixed and small granulocyte phenotypes of bronchial asthma, and describes the most frequent correlations of phenotypes with the severity and course of the disease, with lung function parameters and other indicators. The paper gives an account of the possibilities of using the induced sputum method for a comprehensive assessment of the course, asthma controllability and the effectiveness of drug therapy, as well as for a personalized selection of an antiinflammatory drug considering the inflammatory phenotype.

The Role of Systems Biology in Deciphering Asthma Heterogeneity

Asthma is one of the most common and lifelong and chronic inflammatory diseases characterized by inflammation, bronchial hyperresponsiveness, and airway obstruction episodes. It is a heterogeneous disease of varying and overlapping phenotypes with many confounding factors playing a role in disease susceptibility and management. Such multifactorial disorders will benefit from using systems biology as a strategy to elucidate molecular insights from complex, quantitative, massive clinical, and biological data that will help to understand the underlying disease mechanism, early detection, and treatment planning. Systems biology is an approach that uses the comprehensive understanding of living systems through bioinformatics, mathematical, and computational techniques to model diverse high-throughput molecular, cellular, and the physiologic profiling of healthy and diseased populations to define biological processes. The use of systems biology has helped understand and enrich our knowledge of asthma heterogeneity and molecular basis; however, such methods have their limitations. The translational benefits of these studies are few, and it is recommended to reanalyze the different studies and omics in conjugation with one another which may help understand the reasons for this variation and help overcome the limitations of understanding the heterogeneity in asthma pathology. In this review, we aim to show the different factors that play a role in asthma heterogeneity and how systems biology may aid in understanding and deciphering the molecular basis of asthma.

Clinical and cytokine patterns of uncontrolled asthma with and without comorbid chronic rhinosinusitis: a cross-sectional study

Background

Asthma is significantly related to chronic rhinosinusitis (CRS) both in prevalence and severity. However, the clinical patterns of uncontrolled asthma with and without comorbid CRS are still unclear. This study aimed to explore the clinical characteristics and cytokine patterns of patients with uncontrolled asthma, with and without comorbid CRS.

Methods

22 parameters associated with demographic characteristics, CRS comorbidity, severity of airflow obstruction and airway inflammation, and inflammation type of asthma were collected and assessed in 143 patients with uncontrolled asthma. Different clusters were explored using two-step cluster analysis. Sputum samples were collected for assessment of Th1/Th2/Th17 and epithelium-derived cytokines.

Results

Comorbid CRS was identified as the most important variable for prediction of different clusters, followed by pulmonary function parameters and blood eosinophil level. Three clusters of patients were determined: Cluster 1 (n = 46) characterized by non-atopic patients with non-eosinophilic asthma without CRS, demonstrating moderate airflow limitation; Cluster 2 (n = 54) characterized by asthma patients with mild airflow limitation and CRS, demonstrating higher levels of blood eosinophils and immunoglobulin E (IgE) than cluster 1; Cluster 3 (n = 43) characterized by eosinophilic asthma patients with severe airflow limitation and CRS (46.5% with nasal polyps), demonstrating worst lung function, lowest partial pressure of oxygen (PaO₂), and highest levels of eosinophils, fraction of exhaled nitric oxide (FeNO) and IgE. Sputum samples from Cluster 3 showed significantly higher levels of Interleukin (IL)-5, IL-13, IL-33, and tumor necrosis factor (TNF)-α than the other two clusters; and remarkably elevated IL-4, IL-17 and interferon (IFN)-γ compared with cluster 2. The levels of IL-10 and IL-25 were not significantly different among the three clusters.

Conclusions

Uncontrolled asthma may be endotyped into three clusters characterized by CRS comorbidity and inflammatory cytokine patterns. Furthermore, a united-airways approach may be especially necessary for management of asthma patients with Type 2 features.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02028-3.

Bronchiectasis in severe asthma and asthmatic components in bronchiectasis

Asthma and bronchiectasis are different diseases; however, differentiating them can be difficult because they share several symptomatic and physiological similarities. Approximately 20% of patients with bronchiectasis have eosinophilic inflammation, 34% show wheezing, and 7-46% have comorbid asthma, although comorbidity with severe asthma may be limited as shown in 3.3% of cases of bronchiectasis. Meanwhile, 25-68% of patients with severe asthma have comorbid bronchiectasis, and at least two phenotypes are present in the accompanying bronchiectasis: eosinophilic bronchiectasis and chronic infectious bronchiolitis/bronchiectasis. Recent studies show that type-2-targeted biologics are effective for eosinophilic bronchiectasis and theoretically effective for some of the remaining cases when used before oral corticosteroids. Further studies are needed to identify treatment strategies for severe asthma with comorbid bronchiectasis and vice versa.

Rethinking neutrophils and eosinophils in chronic rhinosinusitis

Chronic rhinosinusitis (CRS) often is characterized by an eosinophilic inflammatory pattern, nowadays referred to as type 2 inflammation, although the mucosal inflammation is dominated by neutrophils in about a third of the patients. Neutrophils are typically predominant in 50% of patients with CRS without nasal polyps, but also are found to play a role in patients with severe type 2 CRS with nasal polyp disease. This review aims at summarizing the current understanding of the eosinophilic and neutrophilic inflammation in CRS pathophysiology, and provides a discussion of their reciprocal interactions and the clinical impact of the mixed presentation in patients with severe type 2 CRS with nasal polyps. A solid understanding of these interactions is of utmost importance when treating uncontrolled severe CRS with nasal polyps with biologicals that are preferentially directed toward type 2 inflammation. We here focus on recent findings on both eosinophilic and neutrophilic granulocytes, their subgroups and the activation status, and their interactions in CRS.

Blood and Salivary Amphiregulin Levels as Biomarkers for Asthma

Background: Amphiregulin (AREG) expression in asthmatic airways and sputum was shown to increase and correlate with asthma. However, no studies were carried out to evaluate the AREG level in blood and saliva of asthmatic patients. Objective: To measure circulating AREG mRNA and protein concentrations in blood, saliva, and bronchial biopsies samples from asthmatic patients. Methods: Plasma and Saliva AREG protein concentrations were measured using ELISA while PBMCs, and Saliva mRNA expression was measured by RT qPCR in non-severe, and severe asthmatic patients compared to healthy controls. Primary asthmatic bronchial epithelial cells and fibroblasts were assessed for AREG mRNA expression and released soluble AREG in their conditioned media. Tissue expression of AREG was evaluated using immunohistochemistry of bronchial biopsies from asthmatic patients and healthy controls. Publicly available transcriptomic databases were explored for the global transcriptomic profile of bronchial epithelium, and PBMCs were explored for AREG expression in asthmatic vs. healthy controls. Results: Asthmatic patients had higher AREG protein levels in blood and saliva compared to control subjects. Higher mRNA expression in saliva and primary bronchial epithelial cells plus higher AREG immunoreactivity in bronchial biopsies were also observed. Both blood and saliva AREG levels showed positive correlations with allergic rhinitis status, atopy status, eczema status, plasma periostin, neutrophilia, Montelukast sodium use, ACT score, FEV1, and FEV1/FVC. In silico analysis showed that severe asthmatic bronchial epithelium with high AREG gene expression is associated with higher neutrophils infiltration. Conclusion: AREG levels measured in a minimally invasive blood sample and a non-invasive saliva sample are higher in non-allergic severe asthma.

CLINICAL IMPLICATIONS

This is the first report to show the higher level of AREG levels in blood and saliva of non-allergic severe asthma.

Bronchial wall thickening is associated with severity of chronic rhinosinusitis

BACKGROUND

Though the relationship between chronic rhinosinusitis (CRS) and lower airway diseases is well recognized, the impact of CRS on bronchial wall structure has not been elucidated. Here, we evaluated the bronchial wall structure of CRS patients with or without diagnosed airway diseases by three-dimensional computed tomography (3D-CT).

METHODS

Subjects who underwent both chest CT and sinus CT within a year were recruited from consecutive medical records. CRS was defined as a Lund-Mackay score (LMS) of over 5 points. Airway dimensions were measured using validated software. Standard blood tests and pulmonary function tests were performed, and their correlation with airway thickness was examined.

RESULTS

One-hundred-seventy-two patients were recruited (93 CRS subjects and 79 non-CRS subjects). The bronchial walls of CRS subjects were significantly thicker than those of non-CRS subjects. CRS and asthma were related to bronchial wall thickening by multivariate linear regression analysis adjusted for age, smoking status, and chest symptoms. In addition, LMS was significantly correlated with bronchial wall thickening.

CONCLUSION

Airway walls in CRS subjects were thicker than those in non-CRS subjects and associated with the severity of CRS. These data indicate strong relationship between upper and lower airways regardless of chest symptoms or diagnosed airway diseases.