The Japanese respiratory society guidelines for the management of cough and sputum (digest edition)

Viscoelastic characteristics of spontaneous sputum obtained from patients with chronic productive cough in comparison to bronchial asthma

BACKGROUND

Chronic respiratory diseases are known to be associated with alterations in mucus rheology, but limited information is available regarding chronic cough. The aim of this study was to determine the sputum rheology in chronic productive cough (CPC) in comparison to bronchial asthma (BA).

METHODS

The viscoelasticity profiles of spontaneous sputum obtained from 26 patients with CPC (10 sinobronchial syndrome [SBS], 16 non-SBS) and 25 patients with BA (12 mild-persistent, 7 moderate, and 6 severe) were analyzed by rheometry in a single center. The non-SBS group included fungus-associated chronic cough, post-COVID-19 cough, bronchorrhea, and unexplained chronic cough.

RESULTS

Viscoelastic modulus (G∗) and viscous modulus (G″) of the SBS group were similar to those of the total BA group. Although critical strain (γC) and critical stress (σC) tended to be larger in the BA group, and the former was comparable between the non-SBS group and the moderate or severe BA group. In the non-SBS group, G″ was closely correlated with FeNO, and γC was inversely correlated with respiratory function, as in the BA group, but no such correlations were observed in the SBS group.

CONCLUSIONS

Quantitative rheological analysis revealed unique viscoelastic characteristics of spontaneous sputum and altered association with clinical biomarkers in the non-SBS group, in which the profile was more similar to BA than SBS in CPC. This new rheometer can identify features of sputum in patients with CPC that cannot be detected by conventional methods. Further investigations of sputum rheology in CPC are warranted to understand its pathogenesis.

Practical Guidelines for Asthma Management (PGAM): Digest edition

The international and national guidelines for asthma management are typically comprehensive and designed for respiratory specialists, making them less practical for primary care physicians who handle most asthma cases. Recognizing the need for more accessible guidelines, the Japan Asthma Society developed the Practical Guidelines for Asthma Management (PGAM). PGAM aims to provide a concise summary of key asthma management principles, increasing awareness, education, and support among nonspecialists and patients alike. It includes user-friendly tables and lists outlining common symptoms, triggers, diagnostic criteria, and basic management strategies, along with frequently encountered treatable traits and comorbidities. These elements are presented through simple, clinically relevant algorithms. A notable feature of PGAM is the "Basic Roadmap for Asthma Management," which outlines a clear sequence for patient assessment, diagnosis, and treatment from initial consultation onward, offering an easy-to-follow visual guide. Additionally, the guidelines include methods for assessing airway inflammation, enabling patient phenotyping and endotyping. This supports a personalized treatment approach, particularly with biologics, aimed at achieving clinical remission.

Phase 3 Trial of the DPP-1 Inhibitor Brensocatib in Bronchiectasis

BACKGROUND

In bronchiectasis, neutrophilic inflammation is associated with an increased risk of exacerbations and disease progression. Brensocatib, an oral, reversible inhibitor of dipeptidyl peptidase 1 (DPP-1), targets neutrophil serine proteases, key mediators of neutrophilic inflammation.

METHODS

In a phase 3, double-blind trial, we randomly assigned patients with bronchiectasis (in a 1:1:1 ratio for adults and a 2:2:1 ratio for adolescents) to receive brensocatib (10 mg or 25 mg once per day) or placebo. The primary end point was the annualized rate of adjudicated pulmonary exacerbations over a 52-week period. The secondary end points, listed in hierarchical testing order, were the time to the first exacerbation during the 52-week period; the percentage of patients remaining exacerbation-free at week 52; the change in forced expiratory volume in 1 second (FEV1); the annualized rate of severe exacerbations; and change in quality of life.

RESULTS

A total of 1721 patients (1680 adults and 41 adolescents) underwent randomization and received brensocatib or placebo. The annualized rate of pulmonary exacerbations was 1.02 in the 10-mg brensocatib group, 1.04 in the 25-mg brensocatib group, and 1.29 in the placebo group (rate ratio, brensocatib vs. placebo, 0.79 [95% confidence interval {CI}, 0.68 to 0.92; adjusted P = 0.004] with the 10-mg dose and 0.81 [95% CI, 0.69 to 0.94; adjusted P = 0.005] with the 25-mg dose). The hazard ratio for the time to the first exacerbation was 0.81 (95% CI, 0.70 to 0.95; adjusted P = 0.02) with the 10-mg dose and 0.83 (95% CI, 0.70 to 0.97; adjusted P = 0.04) with the 25-mg dose. In each brensocatib group, 48.5% of patients remained exacerbation-free at week 52, as compared with 40.3% in the placebo group (rate ratio, 1.20 [95% CI, 1.06 to 1.37; adjusted P = 0.02] with the 10-mg dose and 1.18 [95% CI, 1.04 to 1.34; adjusted P = 0.04] with the 25-mg dose). At week 52, FEV1 had declined by 50 ml with the 10-mg dose, 24 ml with the 25-mg dose, and 62 ml with placebo (least-squares mean difference vs. placebo, 11 ml [95% CI, -14 to 37; adjusted P = 0.38] with the 10-mg dose and 38 ml [95% CI, 11 to 65; adjusted P = 0.04] with the 25-mg dose). The incidence of adverse events was similar across groups, except for a higher incidence of hyperkeratosis with brensocatib.

CONCLUSIONS

Among patients with bronchiectasis, once-daily treatment with brensocatib (10 mg or 25 mg) led to a lower annualized rate of pulmonary exacerbations than placebo, and the decline in FEV1 was less with the 25-mg dose of brensocatib than with placebo. (Funded by Insmed; ASPEN ClinicalTrials.gov number, NCT04594369; EudraCT number, 2020-003688-25.).

Effectiveness of ensitrelvir for cough caused by COVID-19 Omicron variant in patients with asthma

In the post-acute coronavirus disease 2019 (COVID-19) period, patients with asthma had a significantly higher risk of cough than patients without a history of asthma. In particular, cases with persistent cough were increased during the Omicron variant epidemic. In this study, we evaluated the efficacy of ensitrelvir for the treatment of cough associated with COVID-19 Omicron variants in patients with asthma. This follows the Strengthening the Reporting of Observational Studies in Epidemiology statement. A total of 223 patients were registered in this study: 121 patients chose ensitrelvir, and 102 patients chose symptomatic treatment. Cough severity, frequency, and cough-specific quality of life were evaluated using the Japanese version of the Leicester Cough Questionnaire (J-LCQ). J-LCQ documented at baseline on days 4, 7, and 14 for all patients showed a steady improvement over time in both groups. In the mixed model for repeated measures model, which accounts for repeated measurements, the change in J-LCQ score from baseline was 2.1 points higher in the ensitrelvir group (P <0.001). Additionally, patients who were using triple inhaled therapy at baseline showed a 2.3-point higher change in J-LCQ score from baseline (P <0.001). Multiple regression analysis was performed at days 4, 7, and 14, with the change in J-LCQ score from baseline as the dependent variable. Ensitrelvir was associated with scores that were 3.1 points higher on day 4, 3.5 points higher on day 7, and 2.0 points higher on day 14 compared with symptomatic treatment (P <0.001 for all). In conclusion, our results demonstrated that early administration of ensitrelvir may be effective as a treatment for cough due to the COVID-19 Omicron variant.

IMPORTANCE

We evaluated the efficacy of ensitrelvir for the treatment of cough due to coronavirus disease 2019 (COVID-19) Omicron variant in patients with asthma. A total of 223 patients were registered in this study: 121 patients chose ensitrelvir, and 102 patients chose symptomatic treatment. Cough severity, frequency, and cough-specific quality of life were evaluated using the Japanese version of the Leicester Cough Questionnaire (J-LCQ). Multiple regression analysis was performed at days 4, 7, and 14, with the change in J-LCQ score from baseline as the dependent variable. Ensitrelvir was associated with scores that were 3.1 points higher on day 4, 3.5 points higher on day 7, and 2.0 points higher on day 14 compared with symptomatic treatment (P <0.001 for all). Our results demonstrated that early administration of ensitrelvir may be effective as a treatment for cough due to the COVID-19 Omicron variant.

Clinical manifestations of COVID-19 Omicron variants in medical healthcare workers: Focusing on the cough

INTRODUCTION

Important points in cough management are that it is necessary to be familiar with the characteristic medical history for each disease, such as infection and cough variant asthma. To clarify whether cough due to SARS-CoV-2 has any characteristics or not, we investigated the clinical manifestations of COVID-19 Omicron variant focused especially on infectious cough.

METHODS

We enrolled adult patients consecutively diagnosed with mild COVID-19 who were medical healthcare workers in our five hospitals. A total of 2449 patients were analyzed: 300 patients with BA.1 subvariant, 202 patients with BA.2 subvariant, 1030 patients with BA.5 subvariant, 413 patients with XBB lineage, 103 patients with BA.2.86, and 401 patients with JN.1 subvariant.

RESULTS

Among the clinical symptoms, cough was most frequent symptom in all Omicron subvariants groups and all age groups. The most frequent pattern of symptoms was cough appearing after pharyngeal symptoms in 38 % of patients, with cough appearing after fever observed in 25.1 % of patients. The pattern in which cough and pharyngeal symptoms were the initial symptoms was observed in 19.6 % of cases, and where cough and fever were the initial symptoms was observed in 14.9 % of cases.

CONCLUSIONS

Cough was the most frequent symptom in patients with COVID-19 Omicron variant and cough was the initial symptom in 1/3 of cases, and 2/3 of cases were preceded by symptoms other than cough. There were few cases of cough only or paroxysmal cough. However, it is considered difficult to differentiate between sources of infectious cough based on symptoms alone.

The Perception of Asthma, Chronic Obstructive Pulmonary Disease, Asthma and Chronic Obstructive Pulmonary Disease Overlap, and Cough Variant Asthma: A Retrospective Observational Study

Objective The prevalence rates of bronchial asthma (BA) and chronic obstructive pulmonary disease (COPD) are 3%-11% and 8%-16%, respectively, in the general Japanese adult population. Few reports on patients' perceptions of BA, cough variant asthma (CVA), COPD, and asthma and COPD overlap (ACO) are available in Japan, and we aimed to investigate the agreement between the perception and diagnosis of BA and COPD-related diseases. Methods The subjects were 229 datasets matched to the sex and age distribution of the Japanese population of 1,000 adult patients who underwent respiratory function tests and screening for each disease at Nagasaki University Hospital between July 2014 and July 2017. The patients' self-perceptions of diagnosed BA, CVA, COPD, emphysema, chronic bronchitis, and ACO were determined. Results In total, 229 datasets were included in this study. The prevalence of BA was 10.0% (23 cases, including 2 CVA and 6 ACO cases) and 11.8% (27 cases, including 6 ACO cases). The prevalence of ACO was 2.6% (28.6% of BA and 22.2% of COPD), and that of CVA was 0.9% (8.7% of BA). The perception of COPD-related diseases had a much lower sensitivity than that of asthma-related diseases (0.481 vs. 0.995, p<0.0001). Cohen's kappa for asthma-related disease was 0.976, and that for COPD-related disease was 0.621. Conclusion Self-perception of asthma-related disease was adequately high, whereas that of COPD-related disease was low. The prevalence rates of BA, COPD, ACO, and CVA in our study were 10.0%, 11.8%, 2.6%, and 0.9%, respectively. An increase in the perception of COPD may help improve community healthcare for respiratory diseases.

The efficacy and safety of Fluticasone Furoate/Umeclidinium/vilanterol (FF/UMEC/VI) on cough symptoms in adult patients with asthma, a randomized double-blind, placebo-controlled, parallel group study: Chronic Cough in Asthma (COCOA) study

BACKGROUND

Persistent cough bothers many patients with asthma because it worsens their quality of life; therefore, it must be remedied immediately. The efficacy of triple therapy as a first-line treatment for cough remains unclear. To evaluate the effectiveness and safety of the triple therapy against persistent cough, the clinical effect of regular treatment with fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) or placebo in adult patients with asthma was investigated.

METHODS

This randomized, double-blind, placebo-controlled, parallel-group multicenter trial recruited asthma patients with persistent cough from hospitals and primary care clinics between June 2022 and December 2023. Participants were randomly given FF/UMEC/VI 200/62.5/25 µg or placebo for 6 wk. The primary endpoint was the average change in the cough symptom score from baseline to week 6. Secondary outcomes were effectiveness on cough-related disease burdens (asthma control questionnaire [ACQ]-5, Leicester cough questionnaire [LCQ] and nighttime awakening). Furthermore, lung function and adverse events were evaluated.

RESULTS

The decrease from baseline in the cough symptom score at week 6 was significantly greater in the FF/UMEC/VI group than in the placebo group (p = 0.006). The ACQ-5 scores showed a greater decrease in the FF/UMEC/VI group than in the placebo group. The change from baseline in morning and evening FEV1 increased in the FF/UMEC/VI group as with the results of peak expiratory flow. No significant adverse events associated with FF/UMEC/VI were noted.

CONCLUSIONS

In asthma patients with persistent cough, FF/UMEC/VI showed an early response and a significant effect on cough and lung function for 6 wk of treatment.

This study is registered with jRCTs031210412.

Causative diseases of bloody sputum and hemoptysis in respiratory clinics in Japan

BACKGROUND

No previous studies have compared respiratory clinics and respiratory specialized facilities regarding causative diseases for bloody sputum and hemoptysis in Japan.

METHODS

We retrospectively compared causative diseases for bloody sputum and hemoptysis between 3 respiratory clinics (clinic group) and 7 departments of respiratory medicine at hospitals (hospital group) in Japan.

RESULTS

We collected data from 231 patients (median age, 51 years; age range, 24-96 years; 109 men (47.2%)) in the clinic group and 556 patients (median age, 73 years; age range, 21-98 years; 302 men (54.3%)) in the hospital group. In the former group, the main causative disease was acute bronchitis (91 patients, 39.4%), acute upper respiratory tract infection (34 patients, 14.7%), and bronchiectasis (BE) (29 patients, 12.6%). In the latter group, the main causative diseases were BE (102 patients, 18.3%), lung cancer (97 patients, 17.4%), and non-tuberculous mycobacterial disease (NTM) (89 patients, 16%). In particular, in patients ≥60 years old, BE was an important causative disease for bloody sputum and hemoptysis in both groups.

CONCLUSIONS

The present study is the first to compare respiratory clinics and respiratory specialized facilities. Depending on the facility in which the patient is examined, lung cancer, BE, and NTM were identified as diseases requiring special attention as causes of bloody sputum and hemoptysis.

Prevalence and causes of subacute cough in Japan

BACKGROUND

Subacute cough is subdivided and distinguished from chronic cough, because post-infectious cough is considered to be the main cause of subacute cough and differs from acute and chronic cough. However, the details of the spectrum and frequency of causes of subacute cough remain unclear because only two studies on subacute cough have been published.

METHODS

Patients who presented with cough that lasted for 3-8 weeks and visited respiratory clinics or hospitals affiliated with the Japan Cough Society during 2 years were studied.

RESULTS

A total of 148 patients were prospectively enrolled, and those who did not meet the definition of subacute cough were excluded. Ninety-seven (68.3%) patients with subacute cough progressed to chronic cough, and the main causative diseases were cough variant asthma in 44 patients, atopic cough in 24 patients, sinobronchial syndrome in 13 patients, and post-infectious cough in seven patients. Patients with cough variant asthma complicated by atopic cough and those in whom the cause of subacute cough was unknown tended to develop chronic cough.

CONCLUSIONS

This study shows that post-infectious cough is less common than previously thought and the main causes of subacute cough are cough variant asthma, atopic cough, and sinobronchial syndrome and their complications. Cough variant asthma in combination with atopic cough also can be a precursor of refractory chronic cough. The careful diagnosis and treatment of two or more causative diseases is required in patients with subacute cough.

Unravelling vagal hypersensitivity in chronic cough: A distinct disease

Chronic cough (CC) is a common but poorly understood disease that has a negative impact on quality of life. For years, clinicians have been trying to find the underlying diagnosis and using existing disease models to describe the patients' illness. This presents a confusing picture of CC. Most patients with CC present with hypersensitivity of the cough reflex, which is characterised by laryngeal paraesthesia and an increased response to the tussive stimuli or an innocuous stimulus that would not trigger coughing in healthy people. Recently, it has been proposed that CC is a unique disease characterised by vagal hypersensitivity that projects to the central nervous system altering responsiveness. The evidence supports the hypothesis that CC is primarily a neurological disorder, consisting of different phenotypes.

Multidisciplinary team discussion based on etiological treatment improves refractory chronic cough outcomes

BACKGROUND

Refractory chronic cough (RCC) causes significant impairments in the life quality of patients. Further research into the identification of etiologies and development of the treatment schedules for RCC is needed.

PATIENTS AND METHODS

We established an multidisciplinary team (MDT) clinic, by integrating respiratory medicine, otorhinolaryngology, and gastroenterology departments, to investigate cough etiologies and the effectiveness of treatment. The therapeutic effect was assessed quantitatively using the Cough Visual Analog Scales (VAS), Leicester Cough Questionnaire (LCQ), and Reflux Symptoms Index (RSI) scores.

RESULTS

In total, 213 patients attending the MDT outpatient clinic were examined, and 115 patients with RCC were included for analysis. The RCC diagnosis rate among the outpatient was 88.7%. Common causes of RCC included gastroesophageal reflux cough (63.5%), upper airway cough syndrome (UACS) (43.5%), and cough variant asthma (CVA) (14.8%). After an average treatment period of 2.17 ± 1.06 weeks (wk), 73.9% of the patients had partial cough remission, and 6.1% had complete cough remission. The cough VAS score before and after treatment was 6.11 ± 2.02 vs. 3.66 ± 2.22 (P < 0.05), respectively; LCQ total score before and after treatment was 10.24 ± 3.11 vs. 13.16 ± 3.59 (P < 0.05), respectively; and RSI score before and after treatment was 15.82 ± 7.01 vs. 10.71 ± 6.64 (P < 0.05), respectively.

CONCLUSION

The etiologies of most patients with RCC could be identified in the MDT clinic, and the cough-related symptoms of a significant number of patients with RCC improved in a short period.

Prevalence and clinical relevance of comorbid pertussis infection in adult patients with asthma: A prospective, cross-sectional study

BACKGROUND

Viral or atypical bacterial respiratory infections are involved in the new development and the pathogenesis of asthma. Though an association between pertussis and asthma has been expected, few studies have reported it consistently. We assessed the prevalence and clinical relevance of pertussis infection in adult patients with asthma.

METHODS

In this prospective, cross-sectional study, newly referred, adult patients with asthma (n = 107) and with non-asthmatic subacute/chronic cough (n = 31) were enrolled. The prevalence of pertussis in patients with asthma and in those with non-asthmatic subacute/chronic cough was assessed. Next, the prevalence of newly diagnosed asthma was compared between asthmatic patients with and without pertussis. Finally, demographic characteristics of patients, blood test results, pulmonary function test results, and questionnaire scores were compared between the two patient groups.

RESULTS

The prevalence of pertussis infection was significantly higher in patients with asthma than in those with non-asthmatic subacute/chronic cough (36% vs 10%; P = 0.004). The prevalence of newly diagnosed asthma was significantly higher in asthmatic patients with pertussis than in those without (74.4% vs 50.0%; P = 0.014). The physical, psychological, and total scores of the Leicester Cough Questionnaire were significantly lower in asthmatic patients with pertussis than in those without (all P < 0.05). The acid-reflux, dyspeptic, and total scores of the Frequency Scale for Symptoms of Gastroesophageal Reflux Disease (GERD) (FSSG) were significantly higher in asthmatic patients with pertussis than in those without (all P ≤ 0.05). The FSSG acid-reflux score was negatively correlated with the cough-specific quality of life (QOL) score only in asthmatic patients with pertussis (rho = -0.68, P = 0.01).

CONCLUSIONS

The prevalence of pertussis infection was significantly higher in adult patients with asthma than in those with non-asthmatic subacute/chronic cough. In patients with asthma, comorbid pertussis infection may play a role in newly diagnosed asthma and may contribute to impaired cough-specific QOL partly due to worsening acid-reflux symptoms of GERD.

Prevalence of refractory and unexplained chronic cough in adults treated in cough centre

Background

Refractory chronic cough and unexplained chronic cough pose significant clinical challenges, impairing patients' quality of life. However, a precise definition of refractory chronic cough remains elusive. This study aimed to assess the prevalence of refractory and unexplained chronic cough among patients referred to our cough centre and to analyse the prevalence of refractory chronic cough relative to its definition.

Methods

This prospective cohort study included all patients who were diagnosed at a cough clinic between 2018 and 2022. The response to therapy was measured based on reduction in cough severity (via a visual analogue scale) and improvement in cough-related quality of life (via the Leicester Cough Questionnaire). Refractory chronic cough was defined as persistent cough severity, with no or minimal improvement (change in visual analogue scale <30 mm) after two or more treatment attempts and cough severity ≥40 out of 100 mm on the visual analogue scale.

Results

Of 201 patients treated for chronic cough, only three (1.5%) were diagnosed with unexplained chronic cough. Among 166 patients monitored for therapy response, 71 (42.8%) experienced a cough severity reduction of ≥30 mm on the visual analogue scale, while 100 (60.2%) showed an improvement of ≥1.5 points on the Leicester Cough Questionnaire. Based on the basic refractory chronic cough definition, 51 of 166 patients (30.7%) were diagnosed with refractory chronic cough. If applying stricter criteria (persistent severe cough (≥40 mm on the visual analogue scale), insufficient therapy response (<30 mm reduction on the visual analogue scale) and <1.5-point improvement on the Leicester Cough Questionnaire), 45 of 166 patients (27.1%) would be diagnosed with refractory chronic cough.

Conclusions

Refractory chronic cough is common in patients referred to cough clinics. The prevalence of refractory chronic cough differs slightly depending on the diagnostic criteria. Therefore, the definition of refractory chronic cough used in routine practice needs to be clarified.

Analysis of the relationship between comorbid obstructive sleep apnea and clinical outcomes in patients with asthma in Japan

BACKGROUND

Asthma and obstructive sleep apnea (OSA) are prevalent chronic respiratory disorders, which often coexist and interact with each other. Obesity is an important risk factor shared by them. The rate of obesity is lower in Japan versus Western countries. Hence, the co-existence of asthma and OSA has not been investigated in Japan.

METHODS

Ninety-seven outpatients with asthma were recruited. Patients wore a portable monitor for sleep study. Background data, pulmonary function, blood tests, and patient-reported outcomes including gastroesophageal reflux disease, sleepiness, sleep quality, asthma control, cough and respiratory symptoms, and health status, were assessed.

RESULTS

Of the patients, 19 (19.6 %), 40 (41.2 %), 24 (24.7 %), and 14 (14.4 %) were classified into non-, mild, moderate, and severe OSA groups. Non-OSA patients were younger than those in other groups (p < 0.05). The BMI of patients with moderate and severe OSA, was higher than that of non-OSA patients (p < 0.05). Pulmonary function, FeNO, serum IgE, and the number of peripheral eosinophils were not significantly different between groups. Nonetheless, compared with the other groups, treatment step was the highest, and the Asthma Control Test, Leicester Cough Questionnaire, COPD Assessment Test, and Asthma Health Questionnaire-33 yielded worst scores in the severe OSA group, and predicted the severe OSA after adjustment by BMI.

CONCLUSIONS

Moderate and severe OSA are highly prevalent among patients with asthma in Japan. Pulmonary function did not differ between groups. However, patients with asthma and severe OSA were linked to more asthma treatment, worse asthma control, more symptoms and cough, and worse health status.

Nationwide survey in Japan of the causative diseases of bloody sputum and hemoptysis in departments of respiratory medicine at university hospitals and core hospitals

BACKGROUND

The Guidelines for the Management of Cough and Sputum (2019) of the Japanese Respiratory Society (JRS) were the first internationally published guidelines for the management of sputum. However, the data used to determine the causative diseases of bloody sputum and hemoptysis in these guidelines were not obtained in Japan.

METHODS

A retrospective analysis was performed using the clinical information of patients with bloody sputum or hemoptysis who visited the department of respiratory medicine at a university or core hospital in Japan.

RESULTS

Included in the study were 556 patients (median age, 73 years; age range, 21-98 years; 302 males (54.3%)). The main causative diseases were bronchiectasis (102 patients (18.3%)), lung cancer (97 patients (17.4%)), and non-tuberculous mycobacterial disease (89 patients (16%)). Sex and age differences were observed in the frequency of causative diseases of bloody sputum and hemoptysis. The most common cause was lung cancer in males (26%), bronchiectasis in females (29%), lung cancer in patients aged <65 years (19%), and bronchiectasis in those aged >65 years (20%).

CONCLUSIONS

The present study is the first to investigate the causative diseases of bloody sputum and hemoptysis using data obtained in Japan. When investigating the causative diseases of bloody sputum and hemoptysis, it is important to take the sex and age of the patients into account.

Prevalence and causes of chronic cough in Japan

BACKGROUND

Chronic cough is one of the most common symptoms of respiratory diseases and can adversely affect patients' quality of life and interfere with social activities, resulting in a significant social burden. A survey is required to elucidate the frequency and treatment effect of chronic cough. However, clinical studies that cover all of Japan have not yet been conducted.

METHODS

Patients who presented with a cough that lasted longer than 8 weeks and visited the respiratory clinics or hospitals affiliated with the Japan Cough Society during the 2-year study period were registered.

RESULTS

A total of 379 patients were enrolled, and those who did not meet the definition of chronic cough were excluded. A total of 334 patients were analyzed: 201 patients had a single cause, and 113 patients had two or more causes. The main causative diseases were cough variant asthma in 92 patients, sinobronchial syndrome (SBS) in 36 patients, atopic cough in 31 patients, and gastroesophageal reflux (GER)-associated cough in 10 patients. The time required to treat undiagnosed patients and those with SBS was significantly longer and the treatment success rate for GER-associated cough was considerably poor.

CONCLUSIONS

We confirmed that the main causes of chronic cough were cough variant asthma, SBS, atopic cough, and their complications. We also showed that complicated GER-associated cough was more likely to become refractory. This is the first nationwide study in Japan of the causes and treatment effects of chronic cough.

Enhancement of Classifier Performance with Adam and RanAdam Hyper-Parameter Tuning for Lung Cancer Detection from Microarray Data-In Pursuit of Precision

Microarray gene expression analysis is a powerful technique used in cancer classification and research to identify and understand gene expression patterns that can differentiate between different cancer types, subtypes, and stages. However, microarray databases are highly redundant, inherently nonlinear, and noisy. Therefore, extracting meaningful information from such a huge database is a challenging one. The paper adopts the Fast Fourier Transform (FFT) and Mixture Model (MM) for dimensionality reduction and utilises the Dragonfly optimisation algorithm as the feature selection technique. The classifiers employed in this research are Nonlinear Regression, Naïve Bayes, Decision Tree, Random Forest and SVM (RBF). The classifiers' performances are analysed with and without feature selection methods. Finally, Adaptive Moment Estimation (Adam) and Random Adaptive Moment Estimation (RanAdam) hyper-parameter tuning techniques are used as improvisation techniques for classifiers. The SVM (RBF) classifier with the Fast Fourier Transform Dimensionality Reduction method and Dragonfly feature selection achieved the highest accuracy of 98.343% with RanAdam hyper-parameter tuning compared to other classifiers.

Safety and efficacy of P2X3 receptor antagonist for the treatment of refractory or unexplained chronic cough: A systematic review and meta-analysis of 11 randomized controlled trials

BACKGROUND AND OBJECTIVES

Chronic refractory cough is a challenging condition that requires a thorough evaluation and management approach. P2X3 receptors that are ATP-dependent play an important part in nerve fiber sensitization and pathological pain pathways. We conducted this systematic review and meta-analysis to determine the long-term safety and efficacy of P2X3 receptor antagonist drugs in chronic cough.

METHODS

We systematically searched PubMed, Scopus, Web of Science, and Embase to identify all relevant published studies through January 15, 2023 that assessed P2X3 antagonists in chronic cough. The protocol was registered in the PROSPERO database with ID: CRD42023422408. Efficacy outcomes were awake (daytime) cough frequency, night cough frequency, 24-h cough frequency, Cough Severity Diary, and total Leicester Cough Questionnaire score. We used the random-effect model to pool the data using RStudio and CMA software.

RESULTS

A total of 11 randomized controlled trials comprising 1350 patients receiving a p2x3 antagonist compared to the placebo group were included in this meta-analysis. A significant decrease in 24-h cough frequency (MD = -4.99, 95% CI [-7.15 to -2.82], P < 0.01), awake (daytime) cough frequency (MD = -7.18, 95% CI [-9.98 to 4.37], P < 0.01), and total Leicester Cough Questionnaire score (MD = 1.74, 95% CI [1.02 to 2.46], P < 0.01) exhibited between the P2X3 antagonist and placebo groups. The frequency of the night cough showed an insignificant difference between the two groups. According to the safety, drug-related adverse events, dysgeusia, hypogeusia, and ageusia significantly increased between the P2X3 antagonist and placebo groups.

CONCLUSION

P2X3 receptor antagonists are promising drugs for treating chronic cough by significantly reducing the frequency, severity, and quality. Some potential side effects may include drug-related adverse events such as hypogeusia, ageusia, and dysgeusia.

Recurrent Cough in the Elderly: A Forgotten Entity

INTRODUCTION

Recurrent cough is little researched in adults. We investigated the prevalence, risk factors, and consequences of recurrent cough, and compared the results to those of isolated chronic cough.

METHODS

Cross-sectional email survey in an elderly community-based population. Recurrent cough was defined as ≥ 3 cough episodes within one year (each lasting ≥ 1 week) and no current chronic cough. Isolated chronic cough was defined as current cough lasting ≥ 8 weeks and no recurrent cough.

RESULTS

The prevalence of recurrent cough was 3.8% among all respondents (n = 5983). Recurrent cough was associated with asthma (aOR 3.32 (95% CI 2.13-5.18)), chronic rhinosinusitis (2.91 (1.89-4.46)), family history of chronic cough (2.59 (1.88-3.56)), analgesic intolerance (2.13 (1.27-3.57)), male gender (1.92 (1.39-2.66)), gastro-esophageal reflux disease (1.73 (1.21-2.47)), obstructive sleep apnoea (1.69 (1.23-2.32)), symptom sum (1.12 per symptom (1.03-1.22)), and younger age (0.96 per year (0.93-1.00)). Isolated chronic cough was associated with chronic rhinosinusitis (3.45 (2.39-4.97)), asthma (2.17 (1.38-3.41), gastro-esophageal reflux disease (1.80 (1.32-2.47)), family history of chronic cough (1.80 (1.35-2.41)), obstructive sleep apnoea (1.49 (1.12-2.00)), symptom sum (1.18 per symptom (1.10-1.27)), and body mass index (0.96 per unit (0.93-1.00)). Among subjects with recurrent and isolated chronic cough, the prevalence of depressive symptoms were 7.7% and 4.2%, p = 0.11, the Leicester Cough Questionnaire total scores 15.2 (14.6-15.8) and 16.3 (16.0-16.6), P = 0.001, and the mean number of yearly cough-related doctor`s visits 0.58 (0.45-0.71) and 0.36 (0.19-0.53), P = 0.007, respectively.

CONCLUSION

The risk factors and consequences of recurrent and isolated chronic cough were comparable. Recurrent cough seems beneficial to address in cough evaluation.

Consensus goals and standards for specialist cough clinics: the NEUROCOUGH international Delphi study

Background

Current guidelines on the management of chronic cough do not provide recommendations for the operation of specialist cough clinics. The objective of the present study was to develop expert consensus on goals and standard procedures for specialist cough clinics.

Methods

We undertook a modified Delphi process, whereby initial statements proposed by experts were categorised and presented back to panellists over two ranking rounds using an 11-point Likert scale to identify consensus.

Results

An international panel of 57 experts from 19 countries participated, with consensus reached on 15 out of 16 statements, covering the aims, roles and standard procedures of specialist cough clinics. Panellists agreed that specialist cough clinics offer optimal care for patients with chronic cough. They also agreed that history taking should enquire as to cough triggers, cough severity rating scales should be routinely used, and a minimum of chest radiography, spirometry and measurements of type 2 inflammatory markers should be undertaken in newly referred patients. The importance of specialist cough clinics in promoting clinical research and cough specialty training was acknowledged. Variability in healthcare resources and clinical needs between geographical regions was noted.

Conclusions

The Delphi exercise provides a platform and guidance for both established cough clinics and those in planning stages.

Efficacy of Gefapixant, a P2X3 Antagonist, for Refractory Atopic Cough

Cough, a frequent symptom encountered in clinical practice, often has a considerable impact on patients' lives. There is an urgent need to investigate more potent antitussive treatments for chronic refractory cough, particularly atopic cough, which is a major cause of chronic refractory cough in Japan. Previous studies have shown that eosinophilic tracheobronchitis with hypersensitivity to sensory nerve C-fibers is the pathophysiology of atopic cough. Gefapixant is a first-in-class P2X3 antagonist that has recently become available for clinical use in patients with refractory coughs. A 64-year-old female non-smoker presented to our hospital with a complaint of chronic intractable cough due to atopic cough. Addition of gefapixant (90 mg/day) to her previous treatment improved her distressing cough, despite the partial efficacy of many other drugs. The findings of this case demonstrate that P2X3 inhibition is a viable therapeutic option for patients with chronic refractory cough caused by atopic cough. This case report offers valuable information regarding currently available treatment options for refractory chronic refractory cough caused by atopic cough. There remains an urgent need to clarify the disease entities presenting with chronic cough that can be effectively treated by inhibiting P2X3.

Association of lower plasma citric acid with prolonged cough: the Nagahama study

Little is known about the association of prolonged cough, a common and troublesome symptom, with metabolic pathways. We aimed to clarify this association using data from the Nagahama cohort, a prospective study of participants from the general population. Self-report questionnaires on prolonged cough were collected at baseline and 5-year follow-up assessments. Blood tests at follow-up were used for gas chromatography-mass spectrometry-based metabolomics. The association between metabolites and prolonged cough was examined using the partial least squares discriminant analysis and multiple regression analysis. Among the 7432 participants, 632 had newly developed prolonged cough at follow-up, which was defined as "new-onset prolonged cough". Low plasma citric acid was significantly associated with new-onset prolonged cough, even after the adjustment of confounding factors including the presence of asthma, upper airway cough syndrome (UACS), and gastroesophageal reflux disease (GERD). A similar association was observed for isocitric acid, 3-hydroxybutyric acid, and 3-hydroxyisobutyric acid. The analysis of these four metabolites revealed that citric acid had the strongest association with new-onset prolonged cough. This significant association remained even when the analysis was confined to participants with UACS or GERD at baseline or follow-up, and these associations were also observed in participants (n = 976) who had prolonged cough at follow-up regardless of baseline status. In conclusion, low blood citric acid may be associated with prolonged cough.

Efficacy of gefapixant, a P2X3 antagonist, for lung cancer-related cough: a case report

Cough is a frequent symptom accompanied by lung cancer. More potent antitussive treatment for this complex and distressing symptom is required, but anti-cancer chemotherapy cannot fully manage the cough. Inhibition of vagal nerves might control coughing in patients with troublesome lung cancer-related cough and P2X3 inhibitory therapy may be useful for targeting neuronal function. We report the case of a woman in her late 70s who never smoked and had advanced lung cancer. She visited our hospital complaining of serious deterioration of a non-productive cough. She was diagnosed with relapse of lung cancer, but she requested 2-week anti-tussive therapy before second-line chemotherapy. Gefapixant (P2X3 antagonist) add-on at a dose of 90 mg/day (45 mg twice daily as the usual dosage in Japan) improved her cough as indicated by an improvement in the visual analog scale for cough from 70 to 20 mm and in the Japanese version of the Leicester Cough Questionnaire from 8.2 to 16.3, despite a deterioration in lung cancer after 2 weeks. There are no current guidelines for cough accompanied by lung cancer; however, our findings suggest that P2X3 inhibition is a potent therapeutic option for lung cancer-related cough.

Guidelines for the management of chronic cough in adults. Endorsed by the French speaking society of respiratory diseases (Société de Pneumologie de Langue Française, SPLF), the Société Française d'Oto-Rhino-Laryngologie et de Chirurgie de la Face et du Cou (SFORL), the Société Française de Phoniatrie et de Laryngologie (SFPL), the Société Nationale Française de Gastro-entérologie (SNFGE)

Patients with chronic cough experience a high alteration of quality of life. Moreover, chronic cough is a complex entity with numerous etiologies and treatments. In order to help clinicians involved in the management of patients with chronic cough, guidelines on chronic cough have been established by a group of French experts. These guidelines address the definitions of chronic cough and the initial management of patients with chronic cough. We present herein second-line tests that might be considered in patients with cough persistence despite initial management. Experts also propose a definition of unexplained or refractory chronic cough (URCC) in order to better identify patients whose cough persists despite optimal management. Finally, these guidelines address the pharmacological and non-pharmacological interventions useful in URCC. Thus, amitryptilline, pregabalin, gabapentin or morphine combined with speech and/or physical therapy are a mainstay of treatment strategies in URCC. Other treatment options, such as P2 × 3 antagonists, are being developed.

[Guidelines for the management of chronic cough in adults]

Patients with chronic cough experience major alteration in their quality of life. Given its numerous etiologies and treatments, this disease is a complex entity. To help clinicians involved in patient management of patients, guidelines have been issued by a group of French experts. They address definitions of chronic cough and initial management of patients with this pathology. We present herein the second-line tests that might be considered in patients whose coughing has persisted, notwithstanding initial management. The experts have also put forward a definition of unexplained or refractory chronic cough (URCC), the objective being to more precisely identify those patients whose cough persists despite optimal management. Lastly, these guidelines indicate the pharmacological and non-pharmacological interventions of use in URCC. Amitriptyline, pregabalin, gabapentin or morphine combined with speech and/or physical therapy are mainstays in treatment strategies. Other treatment options, such as P2X3 antagonists, are being developed and have generated high hopes among physicians and patients alike.

Usefulness of simultaneous impulse oscillometry and spirometry with airway response to bronchodilator in the diagnosis of asthmatic cough

Objective: Some of the most common causes of chronic cough include cough variant asthma (CVA), bronchial asthma (BA), and asthma-COPD overlap (ACO). Although there is some overlap in the etiology of these diseases, it is clinically important to attempt an early differential diagnosis due to treatment strategies and prognoses.Methods: Spirometry and impulse oscillometry (IOS) before and after bronchodilator inhalation were analyzed for clinically diagnosed CVA (cCVA, n = 203), BA (cBA, n = 222), and ACO (cACO, n = 61).Results: A significant difference in ΔFEV₁ was observed between cBA and cCVA (ΔFEV₁ improvement of 122.5 mL/5.4% and 65.7 mL/2.2%, respectively), but no difference was observed in ΔPEF, ΔV50, or ΔV25. Except for R20 (resistance at 20 Hz), significant differences between the three groups were observed in IOS. In IOS, cCVA and cBA showed comparable peripheral airway response to bronchodilator which was thought to be commensurate with changes in V50 and V25. cACO improved ΔFEV₁ improvement of 81.0 mL/6.2% and was distinguished by a downward respiratory system reactance (Xrs) waveform with a limited bronchodilator response. FEV₁/FVC, %FEV₁, and %V25 had relatively strong correlations with the three IOS parameters, X5 (reactance at 5 Hz), resonant frequency (Fres), and low-frequency reactance area (ALX), in the correlation between IOS and spirometers.Conclusion: Changes in IOS parameters were more sensitive in this study than changes in FEV₁ or the flow-volume curve. Considering the benefits and relevance of the two different tests, simultaneous IOS and spirometry testing were useful in the diagnosis of asthmatic cough.

Executive summary: Japanese guidelines for adult asthma (JGL) 2021

Asthma is characterized by chronic airway inflammation, variable airway narrowing, and sensory nerve irritation, which manifest as wheezing, dyspnea, chest tightness, and cough. Longstanding asthma may result in airway remodeling and become intractable. Despite the increased prevalence of asthma in adults, asthma-associated deaths have decreased in Japan (0.94 per 100,000 people in 2020). The goals of asthma treatment include the control of symptoms and reduction of future risks. A functional partnership between physicians and patients is indispensable for achieving these goals. Long-term management with medications and the elimination of triggers and risk factors are fundamental to asthma treatment. Asthma is managed via four steps of pharmacotherapy ("controllers"), ranging from mild to intensive treatments, depending on disease severity; each step involves daily administration of an inhaled corticosteroid, which varies from low to high dosage. Long-acting β₂ agonists, leukotriene receptor antagonists, sustained-release theophylline, and long-acting muscarinic antagonists are recommended as add-on drugs. Allergen immunotherapy is a new option that is employed as a controller treatment. Further, as of 2021, anti-IgE antibody, anti-IL-5 and anti-IL-5 receptor α-chain antibodies, and anti-IL-4 receptor α-chain antibodies are available for the treatment of severe asthma. Bronchial thermoplasty can be performed for asthma treatment, and its long-term efficacy has been reported. Algorithms for their usage have been revised. Comorbidities, such as allergic rhinitis, chronic rhinosinusitis, chronic obstructive pulmonary disease, and aspirin-exacerbated respiratory disease, should also be considered during the treatment of chronic asthma. Depending on the severity of episodes, inhaled short-acting β₂ agonists, systemic corticosteroids, short-acting muscarinic antagonists, oxygen therapy, and other approaches are used as needed ("relievers") during exacerbation.

A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Phase 2b Trial of P2X3 Receptor Antagonist Sivopixant for Refractory or Unexplained Chronic Cough

INTRODUCTION

To determine the optimal dose of sivopixant, a highly selective P2X3 receptor antagonist, for refractory or unexplained chronic cough (RCC/UCC).

METHODS

In this phase 2b, randomized, double-blind, placebo-controlled, parallel-group, multicenter trial, patients received sivopixant 50, 150, or 300 mg or placebo once daily for 4 weeks. The primary endpoint was a change from baseline in 24-h cough frequency (coughs/h) with sivopixant vs placebo.

RESULTS

Overall, 390/406 randomized patients completed the study. Placebo-adjusted changes in hourly cough count over 24 h were 13.17% (P = 0.3532), - 1.77% (P = 0.8935), and - 12.47% (P = 0.3241) and in cough severity (visual analog scale) were 1.75 mm (P = 0.5854), - 1.21 mm (P = 0.7056), and - 6.55 mm (P = 0.0433) with sivopixant 50, 150, and 300 mg, respectively. Placebo-adjusted changes from baseline in Leicester Cough Questionnaire total scores were - 0.37 (P = 0.4207), - 0.07 (P = 0.8806), and 0.69 (P = 0.1473) with sivopixant 50, 150, and 300 mg, respectively. Additionally, 61.3%, 78.3%, 86.8%, and 71.4% of patients receiving sivopixant 50, 150, and 300 mg and placebo, respectively, reported any improvements in Patient Global Impression of Change. The incidence of treatment-emergent adverse events (TEAEs) was 25.7%, 32.0%, 49.0%, and 20.6% in sivopixant 50, 150, and 300 mg and placebo groups, respectively; all TEAEs in the sivopixant group were mild-to-moderate.

CONCLUSION

Sivopixant did not demonstrate a statistically significant difference vs placebo in change from baseline in 24-h cough frequency. The dose of 300 mg has potential for RCC/UCC, showing the greatest improvements in cough frequency and patient-reported outcomes and dose-related mild to moderate reversible taste disturbance, although further trials are needed.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT04110054; registered September 26, 2019.

Clinical characteristics and drug utilisation patterns in patients with chronic cough: a retrospective cohort study using a Japanese claims database

BACKGROUND

Although unmet medical needs for better care of patients with chronic cough exist in Japan, epidemiological information about these patients and their treatments is very limited.

OBJECTIVES

To describe patient characteristics, underlying cough-related diseases and drug utilisation patterns in patients with chronic cough, and their changes over time.

METHODS

This large retrospective claims database study enrolled subjects with chronic cough, identified either by a specific diagnostic cough code for chronic cough (Population 1) or by multiple cough-related diagnostic codes spanning > 8 weeks (Population 2). Within Population 2, patients with each of the three most frequent diagnostic cough codes were analysed as subgroups. Patient characteristics, underlying cough-related diseases and utilisation patterns for drugs used for cough were documented at the index date, during the 6-month pre-index period and during the 12-month post-index period.

RESULTS

6,038 subjects were enrolled in the cohort (Population 1: N = 3,500; Population 2: N = 2,538). The mean age was 43.7 ± 12.2 years and 61.8% were women. The largest cough diagnosis subgroups in Population 2 were 'other coughs' (N = 1,444), 'cough-variant asthma' (N = 1,026) and 'atopic/allergic cough' (N = 105). At the index date, the most frequent underlying cough-related diseases were allergic rhinitis/nasal inflammation (N = 3,132; 51.9%), asthma (N = 2,517; 41.7%) and gastro-esophageal reflux disease (N = 829; 13.7%). At the index date, 4,860 participants (80.5%) were prescribed at least one cough-related treatment. 194 participants (4.0% of medication users) were prescribed central antitussives alone, principally in Population 1, and 2,331 (48.0%) were prescribed expectorants. Other frequently prescribed medications were antiallergic drugs (N = 2,588; 53.3%), antimicrobials (N = 1,627; 34.4%) and inhaled corticosteroids with long-acting beta-agonists (N = 1,404; 28.9%). Over time, cough diagnoses tended to be lost, with only 470 participants in Population 1 retaining a diagnostic code for chronic cough one year later. The frequency of underlying cough-related diseases was stable over time.

CONCLUSIONS

Patients in this cohort with chronic cough are most frequently identified by a diagnostic cough code for chronic cough, followed by codes for other coughs, cough-variant asthma and atopic cough. Chronic cough frequently presents with an underlying cough-related disease, most frequently allergic rhinitis/nasal inflammation, asthma or GERD. Medication prescription for the underlying cough-related diseases was generally appropriate.

A phase 3, randomized, double-blind, clinical study to evaluate the long-term safety and efficacy of gefapixant in Japanese adult participants with refractory or unexplained chronic cough

BACKGROUND

In two phase 3, global clinical trials (COUGH-1 and COUGH-2), the P2X3-receptor antagonist gefapixant significantly reduced objective 24-h cough frequency in participants with refractory or unexplained chronic cough (RCC or UCC) at a dosage of 45 mg twice daily (BID), with an acceptable safety profile. The primary objective of this phase 3, randomized, double-blind, parallel-group study was to assess the safety and tolerability of gefapixant in Japanese participants with RCC or UCC (ClinicalTrials.gov, NCT03696108; JAPIC-CTI, 184154).

METHODS

Participants aged ≥20 years with chronic cough lasting ≥4 months and a diagnosis of RCC or UCC despite treatment in accordance with Japanese Respiratory Society guidelines were randomized 1:1 to receive gefapixant 15 or 45 mg BID for 52 weeks. The primary objective was to evaluate the safety and tolerability of gefapixant, including adverse events (AEs) and discontinuations due to AEs. Cough-specific quality of life was assessed using the Leicester Cough Questionnaire as a secondary objective.

RESULTS

Of 169 randomized and treated participants, 63% were female and mean age was 58 years. Adverse events were reported by 79 (94%) and 82 (96%) participants in the 15- and 45-mg BID groups, respectively. Most treatment-related AEs were taste related. Discontinuations due to AEs occurred in 6 (7%) and 17 (20%) participants receiving gefapixant 15 or 45 mg BID, respectively. There were no serious treatment-related AEs or deaths. Leicester Cough Questionnaire total scores improved from baseline through Week 52.

CONCLUSIONS

Gefapixant had an acceptable safety profile, with no serious treatment-related AEs in Japanese participants.

Non-pharmacological Management of Non-productive Chronic Cough in Adults: A Systematic Review

Background

Chronic cough is a common reason for medical referral and its prevalence is on the rise. With only one pharmaceutical therapy currently under review for the treatment of refractory chronic cough, exploring non-pharmacological chronic cough management therapies is important. This systematic review summarizes the effectiveness of non-pharmacological chronic cough therapies in adults with non-productive refractory chronic cough or cough due to chronic respiratory diseases.

Methods

We searched Medline, Embase, Cochrane, CINAHL, and Scopus from inception to September 2021. Randomized controlled trials published in English, Portuguese, or French, and examining the effects of non-pharmacological therapies in adults with chronic non-productive cough (>8 weeks; <2 teaspoons sputum) were included. Mean differences, medians, and odds ratios were calculated as appropriate.

Results

16,546 articles were identified and six articles representing five unique studies were included. Studies evaluated 228 individuals with refractory chronic cough or chronic cough due to a chronic respiratory disease [162 women (71%); 52 ± 11 to 61 ± 8 years old]. Obstructive sleep apnea was the only chronic respiratory disease studied. Non-pharmacological therapies included education, cough suppression, breathing techniques, mindfulness, and continuous positive airway pressure. When standing alone, non-pharmacological cough therapies improved cough-specific health related quality of life when not associated with interventions (mean diff MD 1.53 to 4.54), cough frequency (MD 0.59 95%CI 0.36 to 0.95), and voice outcomes (MD 0.3 to 1) when compared to control interventions.

Conclusion

The evidence of non-pharmacological therapies for non-productive chronic cough is limited. Existing studies reflect the heterogeneity in study design, sample size, and outcome measures. Thus, clinical recommendations for using the most effective interventions remain to be confirmed.

A new method for objectively evaluating nocturnal cough in adults

BACKGROUND

For the management of cough diseases in adults, an objective method of evaluating nocturnal cough is required.

METHODS

In Study 1, a cough monitoring system was evaluated using 25 adult volunteers. In Study 2, the cough monitoring system was validated using 20 samples from 10 adult patients with cough diseases obtained overnight. In hospitalized patients, our original cough monitoring system with a microphone and accelerometer was used. At the same time, coughs were recorded using a video camera with digital sound recording. The number of coughs in each 8-h video-audio recording was counted manually by three trained observers. All cough data were printed out, and the basal number of cough events, using both the printed-out data and video-audio recordings, were then calculated by three observers.

RESULTS

In Study 1, the cough monitoring system demonstrated good agreement with the number of coughs counted by examiners (sensitivity 99.2%, specificity 98.9%). In Study 2, there was significant agreement in the counts of natural coughs between our system and the video-audio method (p < 0.0001) and between our system and the basal cough events (p < 0.0001).

CONCLUSIONS

Our method demonstrated excellent agreement with the video-audio recording method in adults and is considered extremely useful for the objective monitoring of overnight cough in adult patients with cough diseases.

Prevalence of chronic cough in China: a systematic review and meta-analysis

Background

Individual studies have indicated variable prevalence for chronic cough, but thus far, there has been no systematic report on the prevalence of this condition.

Methods

In this study, we performed a systematic review and meta-analysis by searching databases including PubMed, Cochrane Library, Web of Science, China National Knowledge Infrastructure, Chinese biomedical literature service system, Wanfang Database, and VIP database, for studies on chronic cough in China published before December 28, 2020. A random effects model was used to calculate pooled prevalence estimates with 95% confidence interval [95%CI], weighted by study size.

Results

Fifteen studies with 141,114 community-based adults were included in the study, showing a prevalence of 6.22% (95% CI 5.03–7.41%). And 21 studies with 164,280 community-based children were included, presenting a prevalence of 7.67% (95% CI 6.24–9.11%). In subgroup meta-analyses, the prevalence in adults was 4.38% (95% CI 2.74–6.02%) in southern China and 8.70% (95% CI 6.52–10.88%) in northern China. In the children population, the prevalence in northern China was also higher than in southern China (northern vs. southern: 7.45% with a 95% CI of 5.50–9.41%, vs. 7.86% with a 95% CI of 5.56–10.16%).

Conclusions

Our population-based study provides relatively reliable data on the prevalence of chronic cough in China and may help the development of global strategies for chronic cough management.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01847-w.

Clinical and Inflammatory Characteristics of the Chinese APAC Cough Variant Asthma Cohort

Background

The AtyPical Asthma in China (APAC) cohort is a multi-center prospective, observational cohort set-up to investigate the clinical, pathophysiological features, prognosis, and mechanisms of cough variant asthma (CVA).

Objectives

To present the characteristics of newly physician-diagnosed adults with CVA (n = 328) compared to mild-moderate classic asthma (CA, n = 206).

Methods and Main Results

CVA subjects showed a higher proportion of female (67.1 vs. 55.3%, P = 0.0084), abnormal laryngopharyngeal sensations (71 vs. 51%, p < 0.0001) than CA, but presented with near normal spirometry and higher methacholine PD20-FEV1 values [4.2 (1, 8.6) vs. 0.8 (0.4, 4.7), P < 0.0001]. Lower fractional exhaled nitric oxide (FENO) levels [38.5 (19.8, 72.5) vs. 53. (28.5, 92.2), P = 0.0019], blood eosinophil counts [0.2 (0.1, 0.4) vs. 0.3 (0.2, 0.5), P = 0.0014], and sputum eosinophils [2.3 (0.3, 8.0) vs. 12.2 (2, 34.5), p < 0.0001] were found in CVA. Despite lower total serum IgE levels in CVA, there was similar proportion of atopy in both groups. The prevalence of cough in CA was 86.4%, while CVA reported more severe cough on Visual Analog Scale, Cough Evaluation Test, and Leicester Cough Questionnaire, similar anxiety and depression scores but better asthma control scores as reflected by Asthma Control Test compared to CA. No correlation was found between cough assessment outcomes and sputum eosinophil count, blood eosinophil count, FENO, spirometry variables, or PD20-FEV1.

Conclusion

Cough variant asthma is distinctive from classic asthma in regard to clinical features, lung function, and airway inflammation. Quality of life is badly impaired as well in spite of better asthma control scores.

Randomised trial of the P2X3 receptor antagonist sivopixant for refractory chronic cough

Background

The purinoceptor subtype P2X₃ has been shown to have significant involvement in the cough reflex; the heterotrimer version of the purinoceptor (P2X_2/3) has been implicated in taste disturbance. The most advanced clinical candidate antagonist gefapixant has low selectivity among P2X₃ receptors and induced taste disturbance, whereas newly developed sivopixant has high selectivity towards P2X₃versus P2X_2/3.

Methods

In a phase 2a, randomised, double-blind, placebo-controlled, crossover, multicentre study, adult patients with refractory or unexplained chronic cough received oral sivopixant 150 mg or placebo once daily for 2 weeks, followed by a 2–3-week washout period, and then crossed over to placebo or sivopixant for 2 weeks. Efficacy and safety of sivopixant were evaluated.

Results

Of 31 randomised patients, 15 in the sivopixant-first group and 15 in the placebo-first group completed the study. After 2 weeks of treatment, the placebo-adjusted ratios of the average hourly number of coughs to baseline during daytime (primary end-point) and over 24 h (secondary end-point) were −31.6% (p=0.0546) and −30.9% (p=0.0386), respectively. Sivopixant also improved health-related quality of life. Treatment-related adverse events occurred in 12.9% and 3.2% of patients during sivopixant and placebo administration, respectively. Mild taste disturbance occurred in two patients (6.5%) during sivopixant administration.

Conclusions

Sivopixant reduced objective cough frequency and improved health-related quality of life, with a low incidence of taste disturbance, among patients with refractory or unexplained chronic cough.

This study shows the efficacy of a highly selective P2X₃ receptor antagonist to reduce cough frequency, with low incidence of taste disturbance. Sivopixant may be a promising therapeutic option for refractory or unexplained chronic cough.https://bit.ly/3awojQH

Efficacy of non-sedating H1-receptor antihistamines in adults and adolescents with chronic cough: A systematic review

Background

Nasal symptoms frequently coexist in patients with chronic cough, and non-sedating H1-receptor antihistamines (nsH1RAs) are often prescribed for cough management in several countries. However, recommendations on the use of nsH1RAs vary among chronic cough guidelines. This study aimed to examine the efficacy of nsH1RAs over placebos in adolescents or adults with chronic cough or allergic respiratory conditions that may present as chronic cough.

Methods

Electronic databases were searched for studies published until November 2020. Randomized placebo-controlled trials of nsH1RAs reporting cough endpoints in adolescents or adults with chronic cough or cough-associated allergic respiratory conditions (allergic rhinitis, allergic asthma, or atopic cough) were included.

Results

A total of 10 placebo-controlled trials were identified. Three studies (one study each involving allergic rhinitis, allergic rhinitis with comorbid asthma, and atopic cough) described baseline and post-treatment cough scores, and all reported significant improvements in subjective cough scores; however, the magnitude of improvement was greater in the 2 studies of patients with atopic cough (relative improvement in cough frequency score: −36.6 ± 8.4%) or seasonal allergic rhinitis-associated cough (cough frequency score: −44.0 ± 7.3% and cough intensity score: −65.7 ± 8.3%) than in the 1 study of allergic rhinitis patients with comorbid asthma (−4.0 ± 1.3%). Meanwhile, the other 7 trials found conflicting results but lacked information on the baseline cough score and did not use validated cough measurement tools; thus, their clinical relevance could not be determined.

Conclusion

Despite the widespread use of nsH1RAs in patients with chronic cough, only a few clinical trials examining their benefits on cough outcomes have been conducted. There may be a subgroup of patients, particularly those with seasonal allergic rhinitis-associated cough or atopic cough, whose cough may improve with nsH1RA treatment. However, adequately powered trials with validated cough measurement tools are warranted to confirm the role of nsH1RAs in the management of patients with allergic phenotypes of chronic cough.