Heterogeneity of perception of symptoms in patients with asthma

The occurrence mechanism, assessment, and non-pharmacological treatment of dyspnea

Dyspnea is a subjective sensation often described as a feeling of respiratory effort, tightness, or air hunger. The underlying mechanisms of this symptom are multifaceted and involve factors such as respiratory centers, cardiovascular system, airways, neuromuscular components, and metabolic factors, although not fully elucidated. The classical theory of imbalance between inspiratory neural drive (IND) and the simultaneous dynamic responses of the respiratory system posits that the disruption of a normal and harmonious relationship fundamentally shapes the expression of respiratory discomfort. Assessment and comprehensive treatment of dyspnea are crucial for patient rehabilitation, including subjective self-reporting and objective clinical measurements. Non-pharmacological interventions, such as pulmonary rehabilitation, fan therapy, exercise, chest wall vibration, virtual reality technology, traditional Chinese medicine (acupuncture and acupressure), and yoga, have shown promise in alleviating dyspnea symptoms. Additionally, oxygen therapy, has demonstrated short-term benefits for patients with pre-hospital respiratory distress and hypoxemia. This review provides a comprehensive overview of dyspnea, emphasizing the importance of a multifaceted approach for its assessment and management, with a focus on non-pharmacological interventions that contribute to enhanced patient outcomes and quality of life.

Bronchial asthma with normal forced expiratory volume in 1 second (FEV1) compared with low FEV1

Background

Cough variant asthma (CVA) is characterized by cough as a sole symptom and normal pulmonary function. However, it is unclear whether CVA really common among asthmatic patients with normal forced expiratory volume in 1 second (FEV1). The aim of this study was to evaluate the incidence of cough alone symptom among the subjects with normal FEV1 and to evaluate their differences from ordinary asthmatic subjects.

Methods

We defined normal FEV1 as ≥90% predicted based on the article of Kotti GH. Of the patients with normal FEV1, we chose subjects without wheeze, and the duration of cough was not to ask, since the symptoms often occurred with acute exacerbation and timing of visiting a doctor depended on each patient's perception. Test for airway hyperresponsiveness was not performed in this study. Visual analogue scale (VAS) scores for cough and dyspnea, FEV1, and fractional exhaled nitric oxide (FeNO) responsiveness to inhaled corticosteroid (ICS)/long-acting beta2 agonist (LABA) treatment were compared in patients with normal FEV1 and with low FEV1 <90%. Correlations of changes in symptoms with changes of FEV1, FeNO, peripheral eosinophil count, and serum immunoglobulin E (IgE) at single time point were also examined in each group and in overall patients.

Results

The participants were 329 physician-diagnosed treatment-naive patients with asthma who were divided into 187 in normal FEV1 and 142 in low FEV1 groups. Cough without dyspnea was present in 16 patients (8.6%) in the normal FEV1 group, suggesting candidates for CVA in this analysis were quite few. Improvement in symptoms after treatment was similar between both groups. But VAS scores of dyspnea were still higher in the low FEV1 group. The degree of improvement in FEV1 after ICS/LABA treatment was less in the normal FEV1 group than in the low FEV1 group, but was still evident. Peripheral eosinophil count, serum IgE, and FeNO values before treatment were lower in the normal FEV1 group. In overall patients, improvements of symptoms after treatment were significantly correlated with FEV1 changes. Improvement of dyspnea was also significantly related to peripheral eosinophil count and change of FeNO, whereas improvement of cough was not related to these T helper 2 (Th2) response markers.

Conclusions

Candidates for CVA among the patients with asthma with predicted FEV1 ≥90% were few. Participants with normal FEV1 respond well to ICS/LABA treatment for improvement of symptom. The change of FEV1 after treatment, and the pre-treatment blood eosinophil count, serum IgE, and FeNO were lower in normal FEV1 cases than in low FEV1 cases. These observations suggest asthmatic patients with normal FEV1, including candidates for CVA having just common mild asthma. In overall participants, symptoms of cough and dyspnea were similar, but were not identical in relation to the Th2 background.

Multidisciplinary management of type 2 inflammation diseases using a screening tool

Dysregulation of type 2 (T2) immune response leads to an aberrant inflammatory reaction that constitutes the pathophysiological basis of diseases involving various organs. For this reason, several disorders can coexist in a single patient; however, as different specialists often treat these pathologies, T2 dysregulation, particularly when mild, is not always the first diagnostic suspicion. A breakdown in interdisciplinary communication or the lack of adequate tools to detect these entities can delay diagnosis, and this, together with a lack of coordination, can lead to suboptimal care. In this context, a multidisciplinary group of specialists in pneumology, immunology, allergology, dermatology and otorhinolaryngology compiled a list of the cardinal symptoms reported by patients presenting with T2 inflammation-related diseases: asthma, chronic rhinosinusitis, allergic rhinitis, allergic conjunctivitis, IgE-mediated food allergy, atopic dermatitis, eosinophilic oesophagitis, and NSAID-exacerbated respiratory disease (NERD). Using this information, we propose a simple, patient-friendly questionnaire that can be administered at any level of care to initially screen patients for suspected coexisting T2 diseases and referral to the appropriate specialist.

Relevance of individual bronchial symptoms for asthma diagnosis and control in patients with rhinitis: A MASK-air study

RATIONALE

It is unclear how each individual asthma symptom is associated with asthma diagnosis or control.

OBJECTIVES

To assess the performance of individual asthma symptoms in the identification of patients with asthma and their association with asthma control.

METHODS

In this cross-sectional study, we assessed real-world data using the MASK-air® app. We compared the frequency of occurrence of five asthma symptoms (dyspnea, wheezing, chest tightness, fatigue and night symptoms, as assessed by the Control of Allergic Rhinitis and Asthma Test [CARAT] questionnaire) in patients with probable, possible or no current asthma. We calculated the sensitivity, specificity and predictive values of each symptom, and assessed the association between each symptom and asthma control (measured using the e-DASTHMA score). Results were validated in a sample of patients with a physician-established diagnosis of asthma.

MEASUREMENT AND MAIN RESULTS

We included 951 patients (2153 CARAT assessments), with 468 having probable asthma, 166 possible asthma and 317 no evidence of asthma. Wheezing displayed the highest specificity (90.5%) and positive predictive value (90.8%). In patients with probable asthma, dyspnea and chest tightness were more strongly associated with asthma control than other symptoms. Dyspnea was the symptom with the highest sensitivity (76.1%) and the one consistently associated with the control of asthma as assessed by e-DASTHMA. Consistent results were observed when assessing patients with a physician-made diagnosis of asthma.

CONCLUSIONS

Wheezing and chest tightness were the asthma symptoms with the highest specificity for asthma diagnosis, while dyspnea displayed the highest sensitivity and strongest association with asthma control.

Glutathione ethyl ester supplementation prevents airway hyper-responsiveness in mice

Background

Oxidative stress plays an important role in the pathogenesis of asthma. Glutathione (GSH) is considered to be one of the most important antioxidants. Our study systematically investigated the effect of the GSH alternative, glutathione ethyl ester (GSH-EE), on airway hyper-responsiveness (AHR) in mice.

Methods

Sixty-three male specific pathogen-free mice were used. Asthma was induced using a single dose of ovalbumin (OVA). The normal group (n=15) received vehicle only [Al(OH)3 in saline]. Then, 48 mice were divided into two groups, including a control group who received sodium phosphate buffer (pH =7.4), and the GSH-EE group who received 0.1% GSH-EE. AHR was measured 2, 6, and 12 hours after exposure to nebulized OVA (0.01%). The animals were then sacrificed, and lung tissue and the bronchi-alveolar lavage fluid (BALF) were harvested. Factors involved in the antioxidant response to asthma were then measured in these tissues, including thiol content (from GSH and protein), γ-glutamylcysteine synthetase (γ-GCS) activity and expression, and nuclear factor-erythroid-2-related factor (Nrf2) expression.

Results

The GSH-EE group showed a significant attenuation of AHR (P<0.01) 2 hours after OVA challenge, and significantly enhanced thiol contents by approximately 45% (P<0.05) at 2 and 6 hours after the last OVA challenge, compared to the control group. γ-GCS activity was also higher in the GSH-EE group compared to the control group at different time points (P<0.01). γ-GCSh and Nrf2 protein expression increased in the GSH-EE group and the control group compared with the normal group, but there was no statistically significant difference (P>0.05) between the GSH-EE group and the control group.

Conclusions

GSH-EE supplementation can prevent AHR in asthmatic mice during the early stages. It may function by serving as a precursor for GSH biosynthesis and by protecting sulfhydryl groups from oxidation.