Value of Exhaled Nitric Oxide and FEF25-75 in Identifying Factors Associated With Chronic Cough in Allergic Rhinitis

Bibliometric Analysis of Cough Variant Asthma from 1993 to 2022

Purpose

Cough variant asthma (CVA) is a chronic inflammatory disease characterized by recurrent coughing, a prevalent cause of chronic cough in children and adults. As a unique form of asthma, researchers have recently become increasingly interested in developing effective diagnostic and treatment methods. Currently, there has been no bibliometric analysis in CVA. Therefore, this study aims to enrich this knowledge network by examining the current development status, research focal points, and emerging trends in this field.

Methods

Articles and reviews on CVA published between 1993 and 2022 were collected from the Web of Science Core Collection (WoSCC) database. Relevant data from the reports were extracted, and collaborative network analysis was performed using CiteSpace and VOSviewer software.

Results

772 articles were included in this study, indicating a significant increase since 2019. The countries with the highest output are China, Japan. The Journal of Asthma and Pulmonary Pharmacology Therapeutics emerged as the most prolific journals in this field. Keyword analysis revealed 22 clusters, highlighting airway inflammation, airway hyperresponsiveness, and eosinophil as the main focus and frontier of research on CVA.

Conclusion

From the visual analysis results, the research of CVA is still in the development stage, and there is no unified definition of pathogenesis, diagnostic criteria and treatment strategies. Therefore, researchers and teams should actively carry out cross-institutional and cross-regional cooperation, expand cooperation areas, and carry out high-quality clinical research in the future.

Is fractional exhaled nitric oxide a treatable trait in chronic cough: a narrative review

Background and Objective

Current management of chronic cough is largely based on sequential therapeutic trials. The concept of treatable traits was first introduced for individualized treatment of chronic airway diseases; however, it has emerged as a potentially useful strategy in revising the management of chronic cough. This narrative review aimed to analyze the literature to determine if fractional exhaled nitric oxide (FeNO) is a treatable trait in chronic cough, compared to other type 2 biomarkers, and to summarize current knowledge and gaps in the clinical application.

Methods

An online electronic search was performed on PubMed, Web of Science, and Scopus of English-language literature with following keywords: cough, nitric oxide (NO), eosinophils, biomarker, and treatable trait. Relevance and eligibility of each article were assessed by one or more of the authors and a narrative review was composed.

Key Content and Findings

Eosinophilic or type 2 airway inflammation is a major treatable trait in patients with chronic cough. Induced sputum tests are regarded as the gold standard for defining inflammatory phenotype, however, technically demanding and cannot be widely applied in clinical practice. FeNO, a practical biomarker, has emerged as an alternative to induced sputum analyses. Mechanistic and clinical evidence indicated that FeNO had a potential for diagnostic utility and treatment response predictability.

Conclusions

FeNO measurement may help to identify patients with chronic cough that will benefit from corticosteroid treatment. Further studies are warranted to determine the diagnostic roles of FeNO in the management of patients with chronic cough.

International consensus statement on allergy and rhinology: Allergic rhinitis - 2023

BACKGROUND

In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation from the full document.

METHODS

ICAR-Allergic Rhinitis 2023 employed established evidence-based review with recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensus was performed for each topic. The final document was then collated and includes the results of this work.

RESULTS

ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost.

CONCLUSION

The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment.

Suhuang Antitussive Capsule Ameliorates Corticosteroid Insensitivity in Cough Variant Asthma Guinea Pigs by Inhibiting p38 MAPK Signal Pathway

Methods

The CVA guinea pig model was successfully established by use of ovalbumin (OVA) sensitization and cigarette smoke (CS) exposure. The guinea pigs were divided into 6 groups: a control group, an OVA model group, an OVA + CS model group, a Suhuang treatment group, a BUD treatment group, and a combination (Suhuang and BUD) treatment group. The effects of the treatment were determined by measuring lung function (RI/Cydn) and cough symptoms (coughs number/cough latency) as outcome criteria. The levels of inflammatory cytokines in bronchoalveolar lavage fluid (BALF) were determined by ELISA. Lung tissues were stained by hematoxylin and eosin (H&E). The expressions of GR/total p38 MAPK/p-p38 MAPK were detected by Western blot. The MKP-1 mRNA levels were detected by RT-PCR.

Results

Combination treatment significantly decreased RI/coughs numbers and increased Cydn/cough latency. Significantly, the results indicated that combination treatment decreased injury to pulmonary tissues. Results also revealed that levels of inflammatory cytokines were reduced in all treatment groups but most markedly in the combination treatment group. Moreover, Suhuang treatment significantly ameliorated corticosteroid insensitivity by improving the expression of glucocorticoid receptors (GR). The expressions of total p38 MAPK and p-p38 MAPK in lung tissue were significantly inhibited in the Suhuang and combination treatment groups. The MKP-1 mRNA levels in Suhuang and combination treatment groups were also increased significantly.

Conclusion

Suhuang was effective for reversing corticosteroid insensitivity by regulating the p38 MAPK signal pathway, and combining BUD and Suhuang treatment showed synergistic interactions in CVA guinea pigs. Our findings showed that this combination therapy might be a promising therapeutic agent for CVA and also clarified its underlying mechanism of action, providing a theoretical basis for clinical combination treatment with Suhuang and BUD in CVA patients.

Role of FEF25-75 in managing children with newly-diagnosed asthma in clinical practice

Background Reversible bronchial obstruction characterizes asthma. Spirometry is the gold standard to assess airflow, and FEV1 is the most reliable parameter in this regard. However, many children with asthma have FEV1 within the normal range despite uncontrolled asthma and worsening. Therefore, FEF25-75 has been proposed as a valuable marker of early airflow impairment. This study aimed at investigating FEF25-75 in a cohort of children with newly diagnosed asthma. Methods 381 children (122 females, mean age 11.6 years) were consecutively visited and had a new asthma diagnosis. In addition, Spirometry, type-2 phenotyping, asthma control assessment, and ACT were performed. Results 72 (18.9%) asthmatic children had impaired FEF25-75, such as <65% of predicted. Low FEF25-75 was associated with lower FVC and FEV1/FVC values (OR 1.11 and 1.32, respectively). Children with normal FEV1 but impaired FEF25-75 had more frequently uncontrolled asthma (15.8% vs. 32.4%) than children with both parameters within the normal range. Conclusions FEF25-75 deserves adequate and careful consideration in children with asthma, and the presence of impaired FEF25-75 values suggests a more compelling approach.

The long-term outcomes of posterior nasal neurectomy with or without pharyngeal neurectomy in patients with allergic rhinitis: a randomized controlled trial

INTRODUCTION

Allergic rhinitis is a form of IgE mediated inflammation of the nasal mucosa in response to specific allergens, resulting in typical symptoms.

OBJECTIVES

This study was designed with the primary goal of comparing the clinical efficacy of posterior nasal neurectomy with or without pharyngeal neurectomy for the treatment of moderate-to-severe perennial allergic rhinitis. Secondary study aims included a comparison of the severity of comorbidities, including chronic cough and asthma, between patients in these two surgical treatment groups.

METHODS

A total of 52 patients were enrolled in this randomized controlled trial and were assigned to either the control group (posterior nasal neurectomy) or the experimental group (posterior nasal neurectomy + pharyngeal neurectomy). The visual analog scale and rhinoconjunctivitis quality of life questionnaire were used to compare the differences in patient symptoms between baseline and 6-, 12-, and 24-months post-treatment. In addition, patient cough and asthma symptoms were monitored during follow-up via visual analog scale and asthma control test respectively.

RESULTS

No significant differences in preoperative scores were evident between groups (p > 0.05). At 6-months post-treatment, there were significant differences in visual analog scale, rhinoconjunctivitis quality of life questionnaire, and asthma control test scores relative to baseline values in experimental group and control group patients (p < 0.05), and this remained true upon 12- and 24-month follow-up. No significant differences in visual analog scale, rhinoconjunctivitis quality of life questionnaire, or asthma control test scores were observed between the two treatment groups at any postoperative follow-up time point (p > 0.05), while coughing severity was found to be significantly reduced in the experimental group relative to the control group (p < 0.05).

CONCLUSION

posterior nasal neurectomy can be safely implemented with or without pharyngeal neurectomy in order to effectively treat allergic rhinitis. Combined posterior nasal neurectomy and pharyngeal neurectomy treatment may offer greater value than posterior nasal neurectomy alone for the treatment of allergic rhinitis patients with chronic cough.

Impaired small airway function in non-asthmatic chronic rhinosinusitis with nasal polyps

BACKGROUND

There is clinical evidence for impaired lung function in chronic rhinosinusitis with nasal polyps (CRSwNP) patients, which may be due to a high incidence of asthma comorbidity. The lung function characteristics of non-asthmatic CRSwNP patients are not known. Small airway dysfunction (SAD) is involved in the pathogenesis of asthma. However, whether SAD is detected in non-asthmatic patients with CRSwNPs remains unclear.

OBJECTIVE

This study analysed the lung function of non-asthmatic patients with CRSwNPs and evaluated its clinical relevance in CRSwNPs.

METHODS

The clinical data for 191 consecutive CRSwNP patients (73 asthmatic and 118 non-asthmatic) and 30 control subjects were prospectively collected. The patients were followed up for at least 3 years (mean [standard deviation], 42.47 ± 8.38 months). Serum and tissue total IgE levels were measured in 95 and 93 patients, respectively. Tissue eosinophil counts were documented in 63 patients.

RESULTS

Non-asthmatic CRSwNP patients had decreased forced expiratory flow at 75% of the FVC (FEF₇₅ ) and FEF₅₀ compared to the control subjects, and this difference was related to the severity of CRSwNP. The risk factors for impaired lung function in asthmatic and non-asthmatic patients were duration of asthma and smoking. A multivariate logistic analysis showed that decreased FEF₅₀ was associated with the recurrence of non-asthmatic CRSwNPs. The lung function of CRSwNP patients negatively correlated with the degree of type-2 inflammation, which was defined by the levels of Eos and IgE in polyp tissues and blood. The SAD of non-asthmatic CRSwNP patients was related to serum IgE levels.

CONCLUSIONS AND CLINICAL RELEVANCE

This study provides evidence that non-asthmatic CRSwNP patients may have SAD, which correlated with the severity and recurrence of CRSwNP. The decreased lung function of patients with CRSwNP was related to the degree of type-2 inflammation.