Higher Prevalence and Severity of Eosinophilic Otitis Media in Patients with Asthma-COPD Overlap Compared with Asthma Alone

INTRODUCTION

Eosinophilic otitis media (EOM) is well-known to frequently co-exist with adult-onset asthma. Both diseases are similar type 2 inflammation and are considered to have a "one airway, one disease" relationship. Asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO), characterized by airway obstruction caused by airway wall thickening (AWT), is a severe condition with a higher incidence of mortality compared to asthma alone or COPD alone. Based on the "one airway, one disease" concept, we hypothesized that the inflammatory pathophysiology of EOM differs depending on its comorbidity with ACO or with asthma alone.

METHODS

A total of 77 chronic rhinosinusitis (CRS) patients with asthma were enrolled in this study. The subjects were divided into 2 groups: a group with comorbid asthma alone (asthma group; 46 patients), and a group with comorbid ACO (ACO group; 31 patients). The 2 groups were compared and assessed with regard to various factors, including the patients' clinical characteristics, prevalence rate of EOM, EOM severity, EOMs relationships with smoking and AWT, and the eosinophil and neutrophil cell counts in the middle ear effusion (MEE).

RESULTS

The ACO group included significantly more males (p < 0.05), was significantly older (p < 0.05), and showed significantly lower lung function values (FEV1 [L], FEV1 [%pred]) (p < 0.01) compared with the asthma group. The ACO group also had a significant history of smoking as shown by the Brinkman index (p < 0.01) and greater AWT as assessed by high-resolution computed tomography (p < 0.05). The EOM prevalence rate was significantly higher in the ACO group (p < 0.05), especially with increased ACO severity (p < 0.05). The EOM severity was also significantly higher in the ACO group (p < 0.05) and also correlated with the ACO severity (p < 0.05). The pretreatment ear clinical characteristics score and the average air conduction hearing level were significantly higher in the ACO group (p < 0.05). The eosinophil percentage in the MEE/otorrhea was significantly lower in the ACO group (25.3%) than in the asthma group (54.7%) (p < 0.05). Conversely, the neutrophil percentage was significantly higher in the ACO group (75.7% vs. 41.9%) (p < 0.05).

CONCLUSIONS

Our findings suggest that, in CRS patients with asthma, comorbidity with ACO may be a clinical factor leading to increased EOM prevalence and severity, as well as a higher neutrophil infiltration percentage in the middle ear. Cessation of smoking and early therapeutic intervention for ACO may mitigate progression of bronchial remodeling (i.e., reduce AWT) and help reduce the prevalence and severity of EOM.

Effects of Benralizumab on Three-Dimensional Computed Tomography Analysis in Severe Eosinophilic Asthma

INTRODUCTION

Benralizumab, an anti-interleukin-5 receptor chain monoclonal antibody, is used to treat severe asthma and control asthma symptoms or exacerbations. The aim of this study was to examine the changes in airway morphology using computed tomography (CT) images in accordance with clinical efficacy following the administration of benralizumab.

METHODS

The clinical efficacy of benralizumab was evaluated in 11 patients with severe asthma by analyzing the changes in parameters, such as the asthma control test, asthma quality of life questionnaire, pulmonary function, and exacerbation count. We also investigated the airway wall thickness of the right bronchus (B1) and the total airway count (TAC) using CT images.

RESULTS

Most patients treated with benralizumab showed improvements in asthma symptoms and exacerbations. CT imaging analyses showed a decrease in the right B1 airway wall thickness and an increase in the TAC. Correlations between blood eosinophil count and changes in CT imaging were observed.

DISCUSSION/CONCLUSION

The data suggested that benralizumab has the potential to improve airway wall thickening and ventilation by alleviating the obstruction and clearing an obstructed airway.

Luminal mucus plugs are spatially associated with airway wall thickening in severe COPD and asthma: A single-centered, retrospective, observational study

BACKGROUND

Airway wall thickening and excess airway mucus occur in asthma and chronic obstructive pulmonary disease (COPD), but few studies have investigated the relationship between them. Our objective was to determine the association between computed tomography (CT) airway wall thickening in segmental airways proximal to airways with or without mucus plugging in patients with asthma and COPD.

METHODS

Mucus plugging was scored using a CT bronchopulmonary segment-based scoring system in asthma and COPD patients. For each of the 19 segmental airways, a mucus plug was defined as complete occlusion of one or more of the daughter branches (sub-segmental airways) by mucus. CT airway measurements were generated for each of the 19 segmental airways: wall-area-percentage (WA%), lumen area (LA), and total airway count (TAC) (VIDA Diagnostics Inc.). Multivariable logistic regression models were constructed for the presence of mucus plugs with corresponding CT measurement and adjusted by covariates; each of the 19 segments was treated as a nested variable.

RESULTS

A total of 33 participants were evaluated. Participants had a mean age of 60 ± 15yrs and there were n = 14 (42%) males. There were 16 (48%) participants with a diagnosis of asthma and 17 (52%) with a COPD diagnosis. The mean FEV₁ was 53 ± 21%pred and FEV₁/FVC was 54 ± 15%. The mean mucus score in all participants was 15 ± 4 (min = 0, max = 19). Multivariable logistic regression analysis showed the presence of airway mucus was significantly associated with increased CT WA% (β = 7.30, p = 0.004) and reduced TAC (β = -0.06, p = 0.045).

CONCLUSIONS

There was increased airway wall thickness and reduced airway counts on CT in segments where there was a distal mucus plug compared to segments without mucus plugs in asthma and COPD.

Chronic exposure to diesel exhaust may cause small airway wall thickening without lumen narrowing: a quantitative computerized tomography study in Chinese diesel engine testers

Background

Diesel exhaust (DE) is a major source of ultrafine particulate matters (PM) in ambient air and contaminates many occupational settings. Airway remodeling assessed using computerized tomography (CT) correlates well with spirometry in patients with obstructive lung diseases. Structural changes of small airways caused by chronic DE exposure is unknown. Wall and lumen areas of 6th and 9th generations of four candidate airways were quantified using end-inhalation CT scans in 78 diesel engine testers (DET) and 76 non-DETs. Carbon content in airway macrophage (CCAM) in sputum was quantified to assess the dose-response relationship.

Results

Environmental monitoring and CCAM showed a much higher PM exposure in DETs, which was associated with higher wall area and wall area percent for 6th generation of airways. However, no reduction in lumen area was identified. No study subjects met spirometry diagnosis of airway obstruction. This suggested that small airway wall thickening without lumen narrowing may be an early feature of airway remodeling in DETs. The effect of DE exposure status on wall area percent did not differ by lobes or smoking status. Although the trend test was of borderline significance between categorized CCAM and wall area percent, subjects in the highest CCAM category has a 14% increase in wall area percent for the 6th generation of airways compared to subjects in the lowest category. The impact of DE exposure on FEV1 can be partially explained by the wall area percent with mediation effect size equal to 20%, P_perm = 0.028).

Conclusions

Small airway wall thickening without lumen narrowing may be an early image feature detected by CT and underlie the pathology of lung injury in DETs. The pattern of changes in small airway dimensions, i.e., thicker airway wall without lumen narrowing caused by occupational DE exposure was different to that (i.e., thicker airway wall with lumen narrowing) seen in our previous study of workers exposed to nano-scale carbon black aerosol, suggesting constituents other than carbon cores may contribute to such differences. Our study provides some imaging indications of the understanding of the pulmonary toxicity of combustion derived airborne particulate matters in humans.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12989-021-00406-1.

Quantitative computed tomography imaging in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease having small airway inflammation, emphysema, and pulmonary hypertension. It is now clear that spirometry alone cannot differentiate each component. Quantitative computed tomography (QCT) is increasingly used to quantify the amount of emphysema and small airway involvement in COPD. Inspiratory CT guides in assessing emphysema while expiratory CT identifies areas of air trapping which is a surrogate of small airway inflammation. By constructing a three-dimensional model of airways, we can also measure the airway wall thickness of segmental and subsegmental airways. The aim of this review is to present the current knowledge and methodologies in QCT of the lung that aid in identifying discrete COPD phenotypes.