Clinical Practice Guidelines for Diagnosis and Management of Cough-Chinese Thoracic Society (CTS) Asthma Consortium

Potassium-Competitive Acid Blocker Versus Proton Pump Inhibitor: A Pilot Study on Comparable Efficacy in the Treatment of Gastroesophageal Reflux-Related Cough

Acid inhibitors have been considered in treating gastroesophageal reflux-related cough (GERC). Compared to proton pump inhibitors (PPIs), potassium-competitive acid blockers (P-CABs) have more potent and durable effects on anti-acid secretion. However, whether vonoprazan and esomeprazole have different therapeutic effects on GERC remains unknown. Patients diagnosed with GERC were enrolled in our study and randomly treated with vonoprazan (20 mg, once daily, P-CAB) or esomeprazole (20 mg, twice daily, PPI) for two months. A prokinetic agent was also administered. Patients were followed up once a month. Cough severity visual analogue scale (VAS) was measured as the primary outcome, while cough symptom score (CSS) and scores for cough-related quality-of-life or reflux-related symptoms were the secondary endpoints. A total of 50 patients completed the study, with 25 patients in each group. P-CAB and PPI groups showed similar decreases in cough severity VAS and CSS scores after the 2-month treatment (all P < 0.001). For quality-of-life, the Leicester Cough Questionnaire (LCQ) score increased significantly from baseline in both groups, but the P-CAB group had greater improvement and a higher LCQ score in month 2 (all P ≤ 0.05). For reflux-related symptoms, the Hull Airway Reflux Questionnaire (HARQ) score declined substantially over time in the P-CAB group, while the reflux symptom index (RSI) score decreased in both groups. The P-CAB group tended to have a lower HARQ (P = 0.051) and RSI (P = 0.069) scores in month 2. In conclusion, vonoprazan may be comparable to esomeprazole in cough symptom relief in GERC during the 2-month treatment period, but possibly provides better gains on classic reflux symptoms and quality-of-life. The long-term efficacy of P-CABs on GERC may be worth further exploration. Trial Registration: Chinese Clinical Trial Registry Identifier: ChiCTR2200067089.

Efficacy and safety of Tanreqing injection for cough caused by acute trachea-bronchitis disease: A systematic review and meta-analysis of randomized controlled trials

ETHNOPHARMACOLOGICAL RELEVANCE

Tanreqing injection (TRQI) is an intravenous herbal preparation derived from 5 types of traditional Chinese medicines including Scutellariae Radix, Lonicerae Japonicae Flos, Forsythiae Fructus, bear bile powder and goral horn, incorporating baicalin, chlorogenic acid, ursodeoxycholic acid, and goose deoxycholic acid and other compounds known for anti-inflammatory properties, is widely used in China to treat cough caused by acute trachea-bronchitis disease (ATB).

AIM OF THE STUDY

To investigate the clinical efficacy and safety of Tanreqing injection (TRQI) with and without Western medicine (WM) for cough caused by acute trachea-bronchitis (ATB).

MATERIALS AND METHODS

We systematically searched eight databases, including CENTRAL, Embase, PubMed, Science Direct, Wiley, China National Knowledge Infrastructure, Chinese Biomedical Literature Database and WanFang, from inception to August 2023 for randomized clinical trials (RCTs) on TRQI for cough caused by ATB. The critical outcomes of interest were time to symptom disappearance, including time for cough symptom to disappear and time to improve cough and sputum production. Important outcomes included symptom disappearance rate, adverse events (AEs) and lung function. We carried out random-effects meta-analysis using Review Manager 5.4 and assessed the certainty of evidence utilizing the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

A total of 2872 citations were identified by our search, of which 26 eligible RCTs enrolled 2731 participants. Low to moderate certainty evidence showed that when compared with WM, TRQI plus WM treatment was associated with a favorable effect on the time for cough symptom to disappear (MD -2.21 d, 95% CI -2.64 to -1.78), time to improve cough and sputum production (MD -0.68 d, 95% CI -0.83 to -0.53), symptom disappearance rate (RR 1.37, 95% CI 1.20 to 1.55), forced vital capacity, and forced expiratory volume in 1 s (MD 0.38 L, 95% CI 0.26 to 0.50; MD 2.92%, 95% CI 1.29 to 4.56, respectively). In terms of AEs, there was no association between TRQI plus WM and WM (RR 0.55, 95% CI 0.14 to 2.21; low-certainty evidence). Very low certainty evidence showed that TRQI alone was associated with reduced time to improve cough and sputum (MD -0.14 d, 95% CI -0.26 to -0.02) and increased symptom disappearance rate (RR 1.89, 95% CI 1.24 to 2.88; low certainty evidence) compared to WM.

CONCLUSIONS

The overall efficacy of TRQI or WM for ATB cough is better than that of WM, and TRQI also effectively improve symptoms in patients with similar adverse events. However, due to the lack of methodological rigor of included studies, the present findings should be interpreted with caution. We advocate better high-quality and convincing clinical studies to be performed to prove the effectiveness and safety of TRQIs.

Improving TB Case Detection Through Active Case-Finding: Results of Multiple Intervention Strategies in Hard-to-Reach Riverine Areas of Southern Nigeria

BACKGROUND

A major challenge to TB control globally is low case detection, largely due to routine health facility-based passive case-finding employed by national TB control programs. Active case-finding is a risk-population-based screening approach that has been established to be effective in TB control. This intervention aimed to increase TB case detection in hard-to-reach areas in southern Nigeria.

METHODS

Using a descriptive cross-sectional design, we conducted implementation research in 15 hard-to-reach riverine local government areas with historically recognized low TB case notification rates. Individuals with TB symptoms were screened using multiple strategies. Data were collected quarterly over a 4-year period using reporting tools and checklists. Descriptive analysis was done with Microsoft Excel spreadsheet 2019.

RESULTS

A total of 1,089,129 individuals were screened: 16,576 in 2017; 108,102 in 2018; 697,165 in 2019; and 267,286 in 2020. Of those screened, 24,802 (2.3%) were identified as presumptive TB, of which 88.8% were tested and 10% were diagnosed with TB (0.23% of those screened). TB notifications more than doubled, increasing by 183.3% and 137.5% in the initial implementation and scale-up, respectively. On average, 441 individuals needed to be screened to diagnose 1 TB case. The cases, predominantly males (56.1%) and aged 15 years and older (77.4%), comprised 71.9% bacteriologically confirmed drug-sensitive TB, 25.8% clinically diagnosed drug-sensitive TB, and 2.3% drug-resistant cases. Detection sources included community outreach (1,786), health facilities (505), people living with HIV (57), and household contacts of bacteriologically confirmed TB cases (123). Remarkably, 98.1% of diagnosed TB cases commenced treatment.

CONCLUSIONS

We found a significant yield in TB case notifications, more than doubling the baseline figures. Given these successful results, we recommend prioritizing resources to support active case-finding strategies in national programs, especially in hard-to-reach areas with high-risk populations, to address TB more comprehensively.

Profiles of Cough and Associated Risk Factors in Nonhospitalized Individuals With SARS-CoV-2 Omicron Variant Infection: Cross-Sectional Online Survey in China

BACKGROUND

Cough is a common symptom during and after COVID-19 infection; however, few studies have described the cough profiles of COVID-19.

OBJECTIVE

The aim of this study was to investigate the prevalence, severity, and associated risk factors of severe and persistent cough in individuals with COVID-19 during the latest wave of the Omicron variant in China.

METHODS

In this nationwide cross-sectional study, we collected information of the characteristics of cough from individuals with infection of the SARS-CoV-2 Omicron variant using an online questionnaire sent between December 31, 2022, and January 11, 2023.

RESULTS

There were 11,718 (n=7978, 68.1% female) nonhospitalized responders, with a median age of 37 (IQR 30-47) years who responded at a median of 16 (IQR 12-20) days from infection onset to the time of the survey. Cough was the most common symptom, occurring in 91.7% of participants, followed by fever, fatigue, and nasal congestion (68.8%-87.4%). The median cough visual analog scale (VAS) score was 70 (IQR 50-80) mm. Being female (odds ratio [OR] 1.31, 95% CI 1.20-1.43), having a COVID-19 vaccination history (OR 1.71, 95% CI 1.37-2.12), current smoking (OR 0.48, 95% CI 0.41-0.58), chronic cough (OR 2.04, 95% CI 1.69-2.45), coronary heart disease (OR 1.71, 95% CI 1.17-2.52), asthma (OR 1.22, 95% CI 1.02-1.46), and gastroesophageal reflux disease (GERD) (OR 1.21, 95% CI 1.01-1.45) were independent factors for severe cough (VAS>70, 37.4%). Among all respondents, 35.0% indicated having a productive cough, which was associated with risk factors of being female (OR 1.44, 95% CI 1.31-1.57), having asthma (OR 1.84, 95% CI 1.52-2.22), chronic cough (OR 1.44, 95% CI 1.19-1.74), and GERD (OR 1.22, 95% CI 1.01-1.47). Persistent cough (>3 weeks) occurred in 13.0% of individuals, which was associated with the risk factors of having diabetes (OR 2.24, 95% CI 1.30-3.85), asthma (OR 1.70, 95% CI 1.11-2.62), and chronic cough (OR 1.97, 95% CI 1.32-2.94).

CONCLUSIONS

Cough is the most common symptom in nonhospitalized individuals with Omicron SARS-CoV-2 variant infection. Being female, having asthma, chronic cough, GERD, coronary heart disease, diabetes, and a COVID-19 vaccination history emerged as independent factors associated with severe cough, productive cough, and persistent cough.

Prevalence of chronic cough, its risk factors and population attributable risk in the Burden of Obstructive Lung Disease (BOLD) study: a multinational cross-sectional study

Background

Chronic cough is a common respiratory symptom with an impact on daily activities and quality of life. Global prevalence data are scarce and derive mainly from European and Asian countries and studies with outcomes other than chronic cough. In this study, we aimed to estimate the prevalence of chronic cough across a large number of study sites as well as to identify its main risk factors using a standardised protocol and definition.

Methods

We analysed cross-sectional data from 33,983 adults (≥40 years), recruited between Jan 2, 2003 and Dec 26, 2016, in 41 sites (34 countries) from the Burden of Obstructive Lung Disease (BOLD) study. We estimated the prevalence of chronic cough for each site accounting for sampling design. To identify risk factors, we conducted multivariable logistic regression analysis within each site and then pooled estimates using random-effects meta-analysis. We also calculated the population attributable risk (PAR) associated with each of the identifed risk factors.

Findings

The prevalence of chronic cough varied from 3% in India (rural Pune) to 24% in the United States of America (Lexington,KY). Chronic cough was more common among females, both current and passive smokers, those working in a dusty job, those with a history of tuberculosis, those who were obese, those with a low level of education and those with hypertension or airflow limitation. The most influential risk factors were current smoking and working in a dusty job.

Interpretation

Our findings suggested that the prevalence of chronic cough varies widely across sites in different world regions. Cigarette smoking and exposure to dust in the workplace are its major risk factors.

Funding

Wellcome Trust.

Role of alveolar nitric oxide in gastroesophageal reflux-associated cough: prospective observational study

BACKGROUND

Fractional exhaled nitric oxide (FeNO) measured at multiple exhalation flow rates can be used as a biomarker to differentiate central and peripheral airway inflammation. However, the role of alveolar nitric oxide (CaNO) indicating peripheral airway inflammation remains unclear in gastroesophageal reflux-associated cough (GERC).

OBJECTIVES

We aimed to characterize the changes in alveolar nitric oxide (CaNO) and determine its clinical implication in GERC.

DESIGN

This is a single-center prospective observational study.

METHODS

FeNOs at exhalation flow rates of 50 and 200 ml/s were measured in 102 patients with GERC and 134 patients with other causes of chronic cough (non-GERC). CaNO was calculated based on a two-compartment model and the factors associated with CaNO were analyzed. The effect of anti-reflux therapy on CaNO was examined in 26 GERC patients with elevated CaNO.

RESULTS

CaNO was significantly elevated in GERC compared with that in non-GERC (4.6 ± 4.4 ppb versus 2.8 ± 2.3 ppb, p < 0.001). GERC patients with high CaNO (>5 ppb) had more proximal reflux events (24 ± 15 versus 9 ± 9 episodes, p = 0.001) and a higher level of pepsin (984.8 ± 492.5 versus 634.5 ± 626.4 pg/ml, p = 0.002) in sputum supernatant than those with normal CaNO. More GERC patients with high CaNO required intensified anti-reflux therapy (χ2 = 3.963, p = 0.046), as predicted by a sensitivity of 41.7% and specificity of 83.3%. Cough relief paralleled a significant improvement in CaNO (8.3 ± 3.0 versus 4.8 ± 2.6 ppb, p < 0.001).

CONCLUSION

Peripheral airway inflammation can be assessed by CaNO measurement in GERC. High CaNO indicates potential micro-aspiration and may predict a necessity for intensified anti-reflux therapy.

A comparison between a gastroesophageal reflux disease questionnaire-based algorithm and multichannel intraluminal impedance-pH monitoring for the treatment of gastroesophageal reflux-induced chronic cough

BACKGROUND

Empiric therapy with multichannel intraluminal impedance-pH monitoring (MII-pH) has been used for the initial treatment of gastroesophageal reflux-induced chronic cough (GERC). However, an algorithm based on the gastroesophageal reflux disease questionnaire (GerdQ) has the potential to achieve a simple, structured, and effective treatment approach for patients with GERC.

OBJECTIVES

This study compared the efficacy of anti-reflux therapy based on GerdQ (new structured pathway, NSP) with medical treatment after MII-pH examination (ordinary clinical pathway, OCP) in the management of GERC.

DESIGN

For the NSP, we adapted the GerdQ score to establish the basis for a treatment algorithm. For the OCP, treatment was determined using the MII-pH examination results.

METHODS

The non-inferiority (NI) hypothesis was used to evaluate NSP versus OCP.

RESULTS

Overall, the NSP and OCP-based therapeutic algorithms have similar efficacy for GERC [NI analysis: 95% confidence interval (CI), -4.97 to 17.73, p = 0.009; superiority analysis: p = 0.420]. Moreover, the cough symptom scores and cough threshold improved faster in the NSP group than in the OCP group at week 8 (p < 0.05). In the subgroup analyses using the GerdQ and GerdQ impact scale (GIS) scores, patients with low-likelihood GERC (GerdQ < 8) were more likely to benefit from OCP (NI analysis: 95% CI, -19.73 to 18.02, p = 0.213). On the other hand, in patients with high-likelihood and low-reflux impact GERC patients (GerdQ > 8 and GIS < 4), the NSP arm was not inferior to the standard treatment of OCP (NI analysis: 95% CI, -8.85 to 28.21%, p = 0.04; superiority analysis: p = 0.339), indicating that GerdQ- and GIS-guided diagnosis and management of patients with GERC could be an alternative to MII-pH management, especially in settings with reduced medical resources.

CONCLUSIONS

The use of the GerdQ algorithm should be considered when handling patients with GERC in the primary care setting.

TRIAL REGISTRATION

This research was registered in the Chinese Clinical Trials Registry (ChiCTR-ODT-12001899).

Sputum Transcriptomics Reveals FCN1+ Macrophage Activation in Mild Eosinophilic Asthma Compared to Non-Asthmatic Eosinophilic Bronchitis

PURPOSE

Eosinophilic asthma (EA) and non-asthmatic eosinophilic bronchitis (EB) share similar eosinophilic airway inflammation. Unlike EA, EB did not present airway hyperresponsiveness or airflow obstruction. We aimed to compare the mechanism underlying the different manifestations between EA and EB via sputum transcriptomics analysis.

METHODS

Induced-sputum cells from newly physician-diagnosed EA, EB patients, and healthy controls (HCs) were collected for RNA sequencing.

RESULTS

Bulk RNA sequencing was performed using sputum cells from patients with EA (n = 18), EB (n = 15) and HCs (n = 28). Principal component analysis revealed similar gene expression patterns in EA and EB. The most differentially expressed genes in EB compared with HC were also shared by EA, including IL4, IL5 IL13, CLC, CPA3, and DNASE1L3. However, gene set enrichment analysis showed that the signatures regulating macrophage activation were enriched in EA compared to EB. Sputum cells were profiled using single-cell RNA sequencing. FABP4+ macrophages, SPP1+ macrophages, FCN1+ macrophages, dendritic cells, T cells, B cells, mast cells, and epithelial cells were identified based on gene expression profiling. Analysis of cell-cell communication revealed that interactions between FCN1+ macrophages and other cells were higher in EA than in EB. A wealth of transforming growth factor beta (TGF-β) and vascular endothelial growth factor (VEGF) interactions between FCN1+ macrophages and other cells have been shown in EA. The gene expression levels of EREG, TGFBI, and VEGFA in FCN1+ macrophages of EA were significantly higher than those of EB. Furthermore, signatures associated with the response to TGF-β, cellular response to VEGF stimulus and developmental cell growth were enriched in FCN1+ macrophages of EA compared to those of EB.

CONCLUSIONS

FCN1+ macrophage activation associated with airway remodeling processes was upregulated in EA compared to that in EB, which may contribute to airway hyperresponsiveness and airflow obstruction.

Inducing Cough Reflex by Capsaicin Spray Stimulation in Patients with Acquired Brain Injury: A Preliminary Test and Proof of Concept

Individuals with acquired brain injuries (ABIs) may experience various complications related to poor coughing or impaired cough reflex (including risk of aspiration pneumonia or respiratory infections). For this reason, cough assessment is an important component in the clinical evaluation since patients with ABI are not able to cough voluntarily due to severe motor deficits. When voluntarily coughing is not possible, it is essential for clinical practices to find a quick and minimally invasive way to induce a cough reflex. In the present study, we evaluated the cough reflex in ABI patients using a new method based on a capsaicin spray stimulation test. In total, 150 healthy controls demographically matched with 50 ABI patients were included in this study. Clinical observations demonstrated robust cough response in both healthy controls and ABI patients, as well as the safety and tolerability of capsaicin spray stimulation. ABI patients with dysphagia were characterized by slower and delayed cough responses. Further studies are needed to validate this feasible, less-invasive, and simple-to-comprehend technique in inducing cough reflex. According to this preliminary evidence, we believe that this test might be translated into a simple and effective treatment to improve reflexive cough modulation in ABI patients.

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.

Exhaled Nitric Oxide as Biomarker of Type 2 Diseases

Nitric oxide (NO) is a short-lived gas molecule which has been studied for its role as a signaling molecule in the vasculature and later, in a broader view, as a cellular messenger in many other biological processes such as immunity and inflammation, cell survival, apoptosis, and aging. Fractional exhaled nitric oxide (FeNO) is a convenient, easy-to-obtain, and non-invasive method for assessing active, mainly Th2-driven, airway inflammation, which is sensitive to treatment with standard anti-inflammatory therapy. Consequently, FeNO serves as a valued tool to aid the diagnosis and monitoring of several asthma phenotypes. More recently, FeNO has been evaluated in several other respiratory and/or immunological conditions, including allergic rhinitis, chronic rhinosinusitis with/without nasal polyps, atopic dermatitis, eosinophilic esophagitis, and food allergy. In this review, we aim to provide an extensive overview of the current state of knowledge about FeNO as a biomarker in type 2 inflammation, outlining past and recent data on the application of its measurement in patients affected by a broad variety of atopic/allergic disorders.

Bacterial Etiology in Subacute Cough

Although postinfectious etiology is the most common cause of subacute cough, there are insufficient data on the epidemiology of associated bacterial infections. We aimed to identify the etiology of bacterial detection in subjects with subacute cough. A multicenter prospective observational study of 142 patients with postinfectious subacute cough was performed between August 2016 and December 2017 in Korea. We obtained 2 nasal swabs from each patient and used a multiplex bacterial polymerase chain reaction (PCR) kit that simultaneously detects Bordetella pertussis, Chlamydophila pneumoniae, Haemophilus influenzae, Legionella pneumophilia, Mycoplasma pneumoniae, and Streptococcus pneumoniae. About 29% (n = 41) of patients with subacute cough were positive for bacterial PCR in nasal swabs. The most common bacteria detected by bacterial PCR was H. influenzae (n = 19, 13.4%), followed by S. pneumoniae (n = 18, 12.7%), B. pertussis (n = 7, 4.9%), M. pneumoniae (n = 3, 2.1%), L. pneumophilia (n = 2, 1.4%), and C. pneumoniae (n = 1, 0.7%). Nine patients had dual positivity for the PCR. In conclusion, bacterial PCR was positive in the nasal swabs of about 29% of subjects with subacute cough, including 5% of positive PCR results for B. pertussis.

Diagnostic accuracy of blood eosinophils in comparison to other common biomarkers for identifying sputum eosinophilia in patients with chronic cough

Background

Sputum eosinophilia is a treatable trait for chronic cough. It is currently not clear whether the blood eosinophil counts could be used to identify sputum eosinophilia in patients with chronic cough. This study aimed to evaluate the diagnostic accuracy of blood eosinophils in comparison to other common type 2 biomarkers for identifying sputum eosinophilia in patients with chronic cough.

Methods

In this prospective study, a total of 658 patients with chronic cough were enrolled. Induced-sputum test, routine blood test, total immunoglobulin E (TIgE), and fractional exhaled nitric oxide (FeNO) level were measured. The percentage of sputum eosinophils (Eos%) ≥ 2.5% was defined as sputum eosinophilia. The area under the curve (AUC) of blood eosinophil counts, TIgE, and FeNO alone or in combination for predicting sputum eosinophilia were analyzed.

Results

The AUC of blood eosinophil counts for predicting sputum eosinophilia in chronic cough patients was moderate [0.826 (0.767-0.885)], as compared to that of FeNO [0.784 (0.720-0.849), P = 0.280] and TIgE [0.686 (0.613-0.760), P = 0.001]. When combining blood eosinophil counts and FeNO for detecting sputum eosinophilia, a significantly larger AUC [0.868 (0.814-0.923), with a sensitivity of 84.2% and a specificity of 82.8%] was yielded, as compared to each single marker alone (all P < 0.05).

Conclusions

Blood eosinophil counts have a moderate diagnostic value for identifying sputum eosinophilia in patients with chronic cough, while a combination of blood eosinophil counts and FeNO measurement can provide additional predictive value.

Effects of bepotastine, a nonsedating H1-antihistamine, for the treatment of persistent cough and allergic rhinitis: a randomised, double-blind, placebo-controlled trial

Background

Empirical therapy with oral histamine-1 receptor antagonists (H1RAs) is often used for patients with suspected upper airway cough syndrome. No placebo-controlled trials with nonsedating H1RAs (nsH1RAs) have evaluated validated cough outcomes. The objective of the present study was to assess the effect of an nsH1RA, bepotastine, on cough outcomes in patients with allergic rhinitis and persistent cough.

Methods

A randomised, double-blind, placebo-controlled trial was conducted. Adult patients with persistent cough (>3 weeks in duration) and symptomatic allergic rhinitis were recruited and randomly assigned to receive either bepotastine or placebo at a 1:1 ratio. The primary outcome was cough-specific quality of life assessed using the Leicester Cough Questionnaire (LCQ). Secondary outcomes included cough severity visual analogue scale (VAS), throat VAS, Cough Hypersensitivity Questionnaire, Sinonasal Outcome Test-22 score and drug adverse events.

Results

Between October 2021 and September 2022, 50 participants (43 females; mean age 46.28 years; median cough duration 3 months) were assigned to either the bepotastine 10 mg twice daily or placebo group in a 1:1 ratio. After 2 weeks of treatment, both bepotastine and placebo groups showed significant improvements in the LCQ scores, but there was no significant difference in the magnitude of change between the groups (3.45±2.10 versus 3.04±2.94, p=0.576). Secondary outcomes were also comparable.

Conclusions

Despite the relatively small sample size, our study clearly demonstrated that a 2-week treatment with bepotastine did not provide therapeutic benefits for cough outcomes. These findings suggest against the use of nsH1RAs with the intention of improving cough outcomes, even in patients with persistent cough and allergic rhinitis.

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.

β-Hydroxybutyric acid upregulated by Suhuang antitussive capsule ameliorates cough variant asthma through GSK3β/AMPK-Nrf2 signal axis

ETHNOPHARMACOLOGICAL RELEVANCE

Cough variant asthma (CVA) is a chronic inflammatory disease characterized by cough as the main symptom. Suhuang antitussive capsule (Suhuang), one of traditional Chinese patent medicines, mainly treats CVA clinically. Previous studies have shown that Suhuang significantly improved CVA, post-infectious cough (PIC), sputum obstruction and airway remodeling. However, the effect of Suhuang on ovalbumin-induced (OVA-induced) metabolic abnormalities in CVA is unknown.

AIM OF THE STUDY

This study aimed to identify potential metabolites associated with efficacy of Suhuang in the treatment of CVA, and determined how Suhuang regulates metabolites, and differential metabolites reduce inflammation and oxidative stress.

MATERIALS AND METHODS

Rats were given 1 mg OVA/100 mg aluminum hydroxide in the 1st and 7th days by intraperitoneal injection and challenged by atomizing inhalation of 1% OVA saline solution after two weeks to establish the CVA model. Rats were intragastrically (i.g.) administrated with Suhuang at 1.4 g/kg and β-hydroxybutyric acid (β-HB) were given with different concentrations (87.5 and 175 mg/kg/day) by intraperitoneal injection for 2 weeks. After 26 days, GC-MS-based metabolomic approach was applied to observe metabolic changes and search differential metabolites. The number of coughs, coughs latencies, enzyme-linked immunosorbent assay (ELISA), histological analysis and quantitative-polymerase chain reaction (Q-PCR) were used to investigate the effects of Suhuang. Then β-HB on CVA rats, NLRP3 inflammasome and GSK3β/AMPK/Nrf2 signalling pathway were detected by western blotting.

RESULTS

The results showed that Suhuang treatment significantly enhanced the serum level of β-HB. Interestingly, exposure to exogenous β-HB was also protective against OVA-induced CVA. β-HB significantly reduced the number of coughs and lengthened coughs latencies, improved lung injury, reduced the secretion of various cytokines, and directly inhibited the NLRP3 inflammasome. In addition, β-HB increased the nuclear accumulation of Nrf2 by activating the GSK3β/AMPK signaling axis, and then inactivating the NF-κB signaling pathway, effectively protecting OVA-induced CVA from oxidative stress and inflammation.

CONCLUSIONS

The results of this study shows that β-HB can reduce inflammation and oxidative stress, the increased production of β-HB in serum might be the crucial factor for Suhuang to exert its effect in the treatment of CVA.

Exposure to second-hand smoke is an independent risk factor of small airway dysfunction in non-smokers with chronic cough: A retrospective case-control study

Objectives

This study aimed to identify the potential risk factors for small airway dysfunction (SAD) in non-smokers with chronic cough.

Methods

Non-smokers with chronic cough who underwent lung function tests at Xiangya Hospital from May 2019 to May 2020 were enrolled, and divided into the derivation and validation cohorts based on their hospital admission time. SAD was determined based on the presence of at least two of the following three indicators of lung function being less than 65% of predicted: maximal mid-expiratory flow, forced expiratory flow at 50% of forced vital capacity (FVC), and forced expiratory flow at 75% of FVC. Clinical data of these patients were collected. Risk factors for SAD were identified by logistic regression analysis in the derivation cohort and further confirmed in the validation cohort.

Results

In total, 316 patients (152 in the non-SAD group and 164 in the SAD group) were included in the derivation cohort. Compared with the non-SAD group, the SAD group had a higher proportion of female patients (82.3 vs. 59.2%, P < 0.001), was more commonly exposed to second-hand smoke (SHS) (61.6 vs. 27.6%, P < 0.001), and tended to be older (median age, 45.5 vs. 40.0 years old, P = 0.004). The median FVC, forced expiratory volume in one second (FEV₁) % pred, FEV₁/FVC ratio, and peak expiratory flow (PEF) % pred were slightly lower in the SAD group. Multivariable logistic analysis showed that exposure to SHS was an independent risk factor (OR 4.166 [95% CI 2.090–8.302], P < 0.001) for SAD in non-smokers with chronic cough after adjusting for related variables. In the validation cohort (n = 146), patients with SHS exposure had a relative risk of 1.976 (95% CI 1.246–3.135, P = 0.004) for SAD compared to those without SHS exposure. Multivariable logistic analysis consistently confirmed that exposure to SHS was an independent risk factor (OR 3.041 [95% CI 1.458–6.344], P = 0.003) for SAD in non-smokers.

Conclusions

Exposure to SHS is independently associated with a higher risk of SAD in non-smokers with chronic cough. Reduction in SHS exposure may ameliorate lung function, thus lowering the risk of irreversible airway obstruction.

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

OBJECTIVES

Risk factors of chronic cough in China have not been systematically analyzed and we hypothesized that risk factors of chronic cough might have distinct characteristics in China. Hence, we performed this meta-analysis focusing on the potential risk factors of chronic cough in China.

METHODS

We searched 7 databases for studies published before May 8, 2021. This systematic review was performed in accordance with the PRISMA checklist.

RESULTS

A total of 33 eligible articles were identified and included in this systematic review, and 28 studies were included in the meta-analysis. Our results showed that allergy (OR: 3.72; 95% CI: 1.85-7.47), nasal/sinusitis diseases (OR: 3.56; 95% CI: 2.02-6.29), family history of allergy (OR = 1.74; 95% CI: 1.59-1.90), family history of chronic respiratory diseases (OR = 1.67; 95% CI: 1.47-1.91), exposure to pollutants (OR = 1.60; 95% CI: 1.26-2.04), passive smoking (OR = 1.44; 95% CI: 1.32-1.57), and exposure to pets (OR = 1.37; 95% CI: 1.18-1.58) were risk factors for chronic cough in China.

CONCLUSIONS

Our study indicated some potential risk factors of chronic cough in China, which provides useful epidemiological information for managing chronic cough in China and is worthy as a reference for future global investigations.

The efficacy of gabapentin for the treatment of refractory cough associated with interstitial lung disease: study protocol for a randomized, double-blind and placebo-controlled clinical trial

Introduction

Gabapentin, a neurotransmitter modulator, is thought to treat refractory cough associated with interstitial lung disease by improving cough hypersensitivity.

Methods/design

This is a single-center, prospective, randomized, double-blind, placebo-controlled trial. The trial will investigate the effect of a 10-week course of oral gabapentin 900 mg/day on refractory cough associated with interstitial lung disease (ILD) and explore the possible mechanisms involved in improving cough symptoms. A total of 84 individuals will be randomized in a 1:1 ratio to two treatment groups and will be followed for a total of 14 weeks from the first dose. The primary endpoint of the study will be the change in cough symptom scores at 14 weeks. The secondary endpoints include the change in Leicester Quality of Life Questionnaire (LCQ), Gastroesophageal Reflux Disease Questionnaire (Gerd Q), and Hull Airway Reflux Questionnaire (HARQ) scores; cough sensitivity (C2 and C5) values; and safety.

Discussion

This study will be the first randomized, controlled clinical trial to investigate gabapentin for the treatment of refractory cough associated with interstitial lung disease and provide data on efficacy, safety, and quality of life. If the study confirms that gabapentin is effective in improving refractory cough associated with interstitial lung disease, it will indicate that a deeper understanding of its mechanisms may reveal new therapeutic targets.

Trial registration

Chinese Clinical Trial Registry ChiCTR2100045202. Registered on 8 April 2021, www.chictr.org.cn

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06059-5.

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.

Distribution, biotransformation, pharmacological effects, metabolic mechanism and safety evaluation of Platycodin D：A comprehensive review

Platycodonis Radix (Jiegeng), the dried root of Platycodon grandiflorum, is a traditional herb used as both medicine and food. Its clinical application for the treatment of cough, phlegm, sore throat, pulmonary and respiratory diseases has been thousands of years in China. Platycodin D is the main active ingredient in Platycodonis Radix, which belongs to the family of pentacyclic triterpenoid saponins because it contains an oleanolane type aglycone linked with double sugar chains. Modern pharmacology has demonstrated that Platycodin D displays various biological activities, such as analgesics, expectoration and cough suppression, promoting weight loss, anti-tumor and immune regulation, suggesting that Platycodin D has the potential to be a drug candidate and an interesting target as a natural product for clinical research. In this review, the distribution and biotransformation, pharmacological effects, metabolic mechanism and safety evaluation of Platycodin D are summarized to lay the foundation for further studies.

Suhuang antitussive capsule ameliorates post-infectious cough in mice through AhR-Nrf2 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Suhuang antitussive capsule (SH capsule), a typical traditional Chinese medicines (TCMs) compound, is widely used for the treatment of post-infectious cough (PIC) in the clinic. Our previous studies have demonstrated that SH capsule possesses significant ameliorative effects on cough variant asthma (CVA), sputum obstruction and airway remodeling.

AIM OF THE STUDY

This study is designed to investigate the ameliorative effects and potential mechanisms of SH capsule on PIC in mice.

MATERIALS AND METHODS

To establish the PIC model, ICR mice were induced by lipopolysaccharide (LPS) (3 mg/kg) once, followed by cigarettes smoke (CS) exposure for 30 min per day for 30 days. Mice were intragastrically (i.g.) administrated with SH capsule at the doses of 3.5, 7, 14 g/kg each day for 2 weeks since the 24th day. The number of coughs, coughs latencies, enzyme-linked immunosorbent assay (ELISA) and histological analysis were used to investigate the effects of SH capsule on PIC mice. Quantitative-polymerase chain reaction (Q-PCR) and western blotting were conducted to evaluate the levels of mRNA and proteins associated with Aryl hydrocarbon receptor (AhR)-NF-E2-related factor 2 (Nrf2) pathway. Superoxide dismutase (SOD), glutathione (GSH) and total antioxidant capacity (T-AOC) assays were performed to evaluate the oxidative stress. A549 cells were used to investigate the ameliorative effects of SH capsule in vitro.

RESULTS

SH capsule effectively diminished the number of coughs and extended coughs latencies in PIC mice. The airway inflammation was alleviated by decreasing the expression levels of inflammatory mediators including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6). Moreover, SH capsule dose-dependently activated AhR-Nrf2 pathway and induced the nuclear translocation in vitro and in vivo. Besides, SH capsule significantly increased the levels of SOD, GSH and T-AOC in mice.

CONCLUSION

Our study demonstrates that SH capsule ameliorates airway inflammation-associated PIC in mice through activating AhR-Nrf2 pathway and consequently alleviating inflammatory responses and oxidative stress.

Small Airway Dysfunction in Cough Variant Asthma: Prevalence, Clinical, and Pathophysiological Features

Introduction: Small airway dysfunction (SAD) commonly presents in patients with classic asthma, which is associated with airway inflammation, disease severity, and asthma control. However, the prevalence of SAD, its relationship with cough severity and airway inflammation, and its development after antiasthmatic treatment in patients with cough variant asthma (CVA) need to be clarified. This study aimed to investigate the prevalence of SAD and its relationship with clinical and pathophysiological characteristics in patients with CVA and the change in small airway function after antiasthmatic treatment.

Methods: We retrospectively analyzed 120 corticosteroid-naïve patients with CVA who had finished a standard questionnaire and relevant tests in a specialist cough clinic, such as cough visual analog scale (VAS), differential cells in induced sputum, fractional exhaled nitric oxide (FeNO) measurement, spirometry, and airway hyper-responsiveness. Information of 1-year follow-up was recorded in a part of patients who received complete cough relief after 2 months of treatment. SAD was defined as any two parameters of maximal mid-expiratory flow (MMEF)% pred, forced expiratory flow at 50% of forced vital capacity (FEF50%) pred, and forced expiratory flow at 75% of forced vital capacity (FEF75%) pred measuring <65%.

Results: SAD occurred in 73 (60.8%) patients with CVA before treatment. The patients with SAD showed a significantly longer cough duration (24.0 vs. 6.0, p = 0.031), a higher proportion of women (78.1 vs. 59.6%, p = 0.029), older mean age (41.9 vs. 35.4, p = 0.005), and significantly lower forced expiratory volume in 1 s (FEV₁%) pred, FEV₁/FVC, MMEF% pred, FEF50% pred, FEF75% pred, PEF% pred, and PD20 (all p < 0.01) as compared with patients without SAD. There were no significant differences in cough VAS, sputum eosinophils count, FeNO, and TIgE level between patients with SAD and those without SAD. Among 105 patients who completed 2 months of antiasthmatic treatment and repeatedly experienced spirometry measurement, 57 (54.3%) patients still had SAD, despite a significant improvement in cough VAS, sputum eosinophils, FeNO, FEF50% pred, and PEF% pred (all p < 0.01). As compared with patients without SAD, patients with SAD showed no significant differences in the relapse rate (50.0 vs. 41.9%, p = 0.483) and wheeze development rate (10.4 vs. 0%, p = 0.063) during the follow-up.

Conclusions: Small airway dysfunction occurred in over half of patients with CVA and persisted after short-term antiasthmatic treatment, which showed distinctive clinical and pathophysiological features.

Expression of interferon-γ and its effect on cough hypersensitivity in chronic refractory cough patients

Chronic refractory cough (CRC) is characterised by cough hypersensitivity. Interferon-γ (IFN-γ) has been reported to induce calcium influx, action potentials of vagal neurons in vitro and cough response in guinea pigs. While the effect of IFN-γ in CRC patients remains unknown. Here, via flow-cytometry and inhalation cough challenge, we found CRC patients had significantly increased levels of sputum IFN-γ⁺CD4⁺ T cells, IFN-γ⁺CD8⁺ T cells as well as supernatant of IFN-γ. The average number of coughs in CRC patients increased as the concentration of inhaled IFN-γ went up in IFN-γ cough challenge. Two or more coughs and five or more coughs elicited by inhaled IFN-γ in CRC patients occurred in 7 of 10 and 2 of 10, respectively. Preinhaled IFN-γ (100 µg/mL) increased the capsaicin cough sensitivity in CRC patients but not healthy volunteers. Targeting IFN-γ may be a potential effective anti-tussive strategy in CRC patients.

Chronic cough: new insights and future prospects

Chronic cough is defined in adults as a cough that lasts for ≥8 weeks. When it proves intractable to standard-of-care treatment, it can be referred to as refractory chronic cough (RCC). Chronic cough is now understood to be a condition of neural dysregulation. Chronic cough and RCC result in a serious, often unrecognized, disease burden, which forms the focus of the current review.The estimated global prevalence of chronic cough is 2-18%. Patients with chronic cough and RCC report many physical and psychological effects, which impair their quality of life. Chronic cough also has a significant economic burden for the patient and healthcare systems. RCC diagnosis and treatment are often delayed for many years as potential treatable triggers must be excluded first and a stepwise empirical therapeutic regimen is recommended.Evidence supporting most currently recommended treatments is limited. Many treatments do not address the underlying pathology, are used off-label, have limited efficacy and produce significant side-effects. There is therefore a significant unmet need for alternative therapies for RCC that target the underlying disease mechanisms. Early clinical data suggest that antagonists of the purinergic P2X3 receptor, an important mediator of RCC, are promising, though more evidence is needed.

Addressing constraints to informal providers' involvement in tuberculosis control: a qualitative study of patent medicine dealers and tuberculosis programme managers

BACKGROUND

A major constraint to tuberculosis control is low case finding with under-reporting to national authorities. Evidence shows that Patent Medicine Dealers are first port of call for most people with symptoms of tuberculosis, yet there is poor referral of such clients to tuberculosis treatment facilities for further evaluation. This study investigated constraints to involvement of Patent Medicine Dealers in tuberculosis control.

METHODS

This was a cross-sectional qualitative study among Patent Medicine Dealers and Tuberculosis Control Programme Managers in Ebonyi State Nigeria. Sixty-four Patent Medicine Dealers and five Tuberculosis Control Programme Managers were interviewed using Focus Group Discussion and In-Depth Interview respectively. Data was collected with electronic audio-recording device and analyzed using thematic approach.

RESULTS

There are some knowledge gaps about tuberculosis signs, symptoms, free-treatment policy and mode of operation of care service among Patent Medicine Dealers. Patent Medicine Dealers and Tuberculosis Control Programme Managers are willing to collaborate in tuberculosis control effort but constant demand for incentives by Patent Medicine Dealers and inability of National Tuberculosis Control Programme to keep up with such demands are obvious constraints.

CONCLUSIONS

Knowledge gaps in tuberculosis, its control, constant demand for incentives by Patent Medicine Dealers and inability of National Tuberculosis Control Programme to satisfy such demands are constraints to involvement of Patent Medicine Dealers in tuberculosis control. More robust engagement of Patent Medicine Dealers in tuberculosis control with clear job description through tuberculosis education and provision of incentives to support them are recommended policy approaches to improve linkage of clients to tuberculosis treatment facilities.

Analysis of the application and efficacy of "Trinity" rehabilitation nursing in management of bronchial asthma

OBJECTIVE

To investigate the application and clinical efficacy of "Trinity" nursing mode in bronchial asthma health management.

METHODS

A total of 100 patients with bronchial asthma admitted to our hospital from June 2017 to June 2020 were divided into a reference group and a research group according to the order of admission (50 cases in each group). The reference group received conventional nursing, while the research group received "Trinity" nursing. The control of asthma, health literacy, hospitalization, treatment compliance and disease recurrence rate were compared between the two groups.

RESULTS

The asthma control test (ACT) score of the research group was higher than that of the reference group; the health literacy score of the research group was higher than that of the reference group; the hospitalization time and treatment cost of the research group were less compared to the reference group. After 1 month of treatment, there was no significant difference between the two groups, and the compliance of the research group was significantly higher than that of the latter after 3 months and 6 months of treatment. The disease recurrence of the research group was significantly lower compared to the reference group 1 month, 3 months, and 6 months after treatment, respectively (P<0.05).

CONCLUSION

"Trinity" nursing mode has a positive clinical effect in the health management of bronchial asthma, which can promote respiratory function and health literacy of patients, help patients save hospitalization expenses, improve treatment compliance and control the recurrence of asthma diseases. Therefore, it is worthy of promotion.

Limited Clinical Utility of Lipid-Laden Macrophage Index of Induced Sputum in Predicting Gastroesophageal Reflux-Related Cough

Gastroesophageal reflux disease (GERD) is a common cause of chronic cough (CC). However, the diagnosis of GERD associated with CC based on 24-hour esophageal pH-monitoring or favorable response to empirical anti-reflux trials is invasive and time-consuming. Lipid-laden macrophages (LLMs) are supposed to be a biomarker for micro-aspiration of gastric content in the respiratory tract. This study was conducted to collect LLMs by the sputum induction technique and observe the relationship among the amount of LLMs, cough severity, parameters of 24-hour esophageal pH-monitoring and therapeutic response. The 24-hour esophageal pH-monitoring and sputum induction were performed on 57 patients with suspected GERD associated with CC. Thirty-four patients were followed up after empirical anti-reflux trials of 8 weeks to record the therapeutic response. Lipid-laden macrophage index (LLMI), a semiquantitative counting of LLMs, showed no significant correlation with the values of 24-hour esophageal pH monitoring at the proximal or remote electrode. No difference in LLMI or DeMeester score, as well as cough symptom association probability, were found between the responders and the non-responders. Reflux symptoms were more common in the responders (50%) compared to the non-responders (6%) (P < 0.05). Our study suggests that LLMI shows limited utility in clinically diagnosing GERD associated with CC as an underlying etiology or in predicting response to anti-reflux therapy. Anti-reflux therapy is more effective for CC patients with reflux symptoms than for those without.

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.

Prevalence, aetiologies and prognosis of the symptom cough in primary care: a systematic review and meta-analysis

Background

Cough is a relevant reason for encounter in primary care. For evidence-based decision making, general practitioners need setting-specific knowledge about prevalences, pre-test probabilities, and prognosis. Accordingly, we performed a systematic review of symptom-evaluating studies evaluating cough as reason for encounter in primary care.

Methods

We conducted a search in MEDLINE and EMBASE. Eligibility criteria and methodological quality were assessed independently by two reviewers. We extracted data on prevalence, aetiologies and prognosis, and estimated the variation across studies. If justifiable in terms of heterogeneity, we performed a meta-analysis.

Results

We identified 21 eligible studies on prevalence, 12 on aetiology, and four on prognosis. Prevalence/incidence estimates were 3.8–4.2%/12.5% (Western primary care) and 10.3–13.8%/6.3–6.5% in Africa, Asia and South America. In Western countries the underlying diagnoses for acute cough or cough of all durations were respiratory tract infections (73–91.9%), influenza (6–15.2%), asthma (3.2–15%), laryngitis/tracheitis (3.6–9%), pneumonia (4.0–4.2%), COPD (0.5–3.3%), heart failure (0.3%), and suspected malignancy (0.2–1.8%). Median time for recovery was 9 to 11 days. Complete recovery was reported by 40.2- 67% of patients after two weeks, and by 79% after four weeks. About 21.1–35% of patients re-consulted; 0–1.3% of acute cough patients were hospitalized, none died. Evidence is missing concerning subacute and chronic cough.

Conclusion

Prevalences and incidences of cough are high and show regional variation. Acute cough, mainly caused by respiratory tract infections, is usually self-limiting (supporting a “wait-and-see” strategy). We have no setting-specific evidence to support current guideline recommendations concerning subacute or chronic cough in Western primary care. Our study presents epidemiological data under non non-pandemic conditions. It will be interesting to compare these data to future research results of the post-pandemic era.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-021-01501-0.

Ayurvedic management of pregnant woman infected with coronavirus disease 2019 ((SARS-CoV-2) - A Case Report

Since 2020, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread globally and is the most threatening health crisis of our time. In this scenario, pregnant women represent a frail category of patients, as they are systematically excluded from trials and thus, a candidate for focused evidence-based care. The Ayurvedic management of second trimester pregnant woman having diagnosed with COVID-19 is reported in this paper. The serologically confirmed COVID–19 pregnant woman was symptomatic and was managed in a tertiary COVID health centre of Ayurveda. The patient became asymptomatic on the 5th day of treatment and on the 7th day, nasopharyngeal swab sample was taken for RT-PCR, which was negative. The patient was followed up to assess the obstetric and neonatal outcomes. The findings of this case report can be useful for understanding the possible clinical pathology of COVID-19 infection in pregnant woman and the holistic care protocol for the management of similar cases.

Coughing children in family practice and primary care: a systematic review of prevalence, aetiology and prognosis

BACKGROUND

For evidence-based decision making, primary care physicians need to have specific and reliable information on the pre-test probabilities of underlying diseases and a symptom's course. We performed a systematic review of symptom-evaluating studies in primary care, following three research questions: (1) What is the prevalence of the symptom cough in children consulting primary care physicians? (2) What are the underlying aetiologies of cough and the respective frequencies? (3) What is the prognosis of children with cough?

METHODS

Following a pre-defined algorithm and independent double reviewer ratings we searched MEDLINE and EMBASE. All quantitative original research articles in English, French or German were included if they focused on unselected study populations of children consulting a primary care physician for cough. We used the random effects model for meta-analysis in subgroups, if justifiable in terms of heterogeneity.

RESULTS

We identified 14 eligible studies on prevalence, five on aetiology and one on prognosis. Prevalence estimates varied between 4.7 and 23.3% of all reasons for an encounter, or up to estimates of 60% when related to patients or consultations. Cough in children is more frequent than in adults, with lowest prevalences in adolescents and in summer. Acute cough is mostly caused by upper respiratory tract infections (62.4%) and bronchitis (33.3%); subacute or chronic cough by recurrent respiratory tract infection (27.7%), asthma (up to 50.4% in cough persisting more than 3 weeks), and pertussis (37.2%). Potentially serious diseases like croup, pneumonia or tuberculosis are scarce. In children with subacute and chronic cough the total duration of cough ranged from 24 to 192 days. About 62.3% of children suffering from prolonged cough are still coughing two months after the beginning of symptoms.

CONCLUSION

Cough is one of the most frequent reasons for an encounter in primary care. Our findings fit in with current guideline recommendations supporting a thoughtful wait-and-see approach in acute cough and a special awareness in chronic cough of the possibility of asthma and pertussis. Further evidence of aetiological pre-test probabilities is needed to assess the diagnostic gain based on patient history and clinical signs for differential diagnoses of cough in children.

Pressure and length of the lower esophageal sphincter as predictive indicators of therapeutic efficacy of baclofen for refractory gastroesophageal reflux-induced chronic cough

BACKGROUND

Therapeutic efficacy of baclofen is suboptimal in the treatment of refractory gastroesophageal reflux-induced chronic cough (GERC). The purpose of the study is to identify its therapeutic predictors in a prospective clinical study.

METHODS

138 patients with suspected refractory GERC were treated with baclofen. Before the therapy, all the patients underwent esophageal manometry and multichannel intraluminal impedance-pH monitoring to establish the diagnosis. After the efficacy of baclofen was evaluated, a stepwise logistic regression analysis was performed to identify the therapeutic predictors of baclofen and to establish a regression prediction model.

RESULTS

The overall response rate of baclofen treatment was 52.2% (72/138). The lower esophageal sphincter pressure (LESP) (odds ratio (OR) = 0.592, P = 0.000) and lower esophageal sphincter length (LESL) (OR = 0.144, P = 0.008) were independent predictors of baclofen efficacy. The optimal cut-off point to predict baclofen efficacy for LESP was 11.00 mmHg, with a sensitivity of 83.7% and specificity of 79.1% while that for LESL was 2.35 cm, with a sensitivity of 81.6% and specificity of 72.1%. The highest predictive specificity (90.7%) was achieved when both LESP and LESL were jointly used.

CONCLUSIONS

LESP and LESL may be used to screen the patients with refractory GERC suitable for baclofen therapy and help improve the therapeutic precision.

CLINICAL TRIAL REGISTRATION

ChiCTR- ONC-13003123.

Addressing unmet needs for diagnosis and management of chronic cough in the primary care setting

Chronic cough (i.e. cough lasting >8 weeks) has a global prevalence of approximately 10% and is associated with substantial patient burden, including social, psychological, and physical impairments. This burden can be long-lasting, with some patients experiencing cough for many years. Although chronic cough is often a symptom of respiratory diseases (e.g. interstitial lung disease, chronic obstructive pulmonary disease) or is associated with comorbid conditions (e.g. asthma, gastroesophageal reflux disease) and may resolve after targeted treatment of these conditions, some patients continue to cough despite optimal treatment of associated conditions (refractory chronic cough (RCC)) or have no identifiable conditions presumed to be contributing to the cough (unexplained chronic cough (UCC)). As both RCC and UCC are diagnoses of exclusion, it is critical to perform a thorough initial patient assessment with adherence to diagnostic guidelines to accurately identify RCC and UCC and provide appropriate treatment. Primary care physicians may be in an important position to provide the initial diagnostic workup of patients with chronic cough as well as identify when referral to specialists (e.g. pulmonologists, allergists, otolaryngologists) is appropriate. In this narrative review, current diagnosis and management guidelines for chronic cough are summarized and recommendations for diagnostic workup in a primary care setting are provided. Increased appreciation of chronic cough as a distinct condition, rather than as only a symptom of other diseases, may help overcome current challenges in diagnosing and managing chronic cough and reduce patient burden.

Causes of chronic cough in adolescent and adult patients

Background: Adolescents differ from adults in certain aspects, but the differences in the etiology of chronic cough between adolescents and adults have not been specifically investigated. The purpose of this study is to evaluate the causes of chronic cough in adolescent patients in comparison with those in adult patients.

Methods: The electronic medical records were retrospectively screened for patients with the initial diagnosis of chronic cough from 2016 to 2018. Clinical variables and the causes of chronic cough were collected in patients who met inclusion criteria. Patients were assigned to adolescent (13 to 18 years) and adult (> 18 years) group based on age. The distribution of causes of chronic cough was compared by t-test and χ2 tests between adolescent and adult groups using SPSS. Significant level was set at 0.05.

Results: The enrolled patients consisted of 16 adolescents and 73 adults with chronic cough. The most common causes of chronic cough were cough-variant asthma and upper airway cough syndrome in both adolescents and adults. The frequency of post infectious cough in adolescents was significantly higher than that in adults (12.5% vs. 1.36%; p= 0.024). Although no significant difference between the two groups was found, there was a trend that suggested that habitual cough was more common in the adolescent group (6.25%:1.36%); while gastroesophageal reflux disease (GERD) did not show similar results (6.25%:20.54%).

Conclusion: There are moderate differences in the causes of chronic cough between adolescent and adult patients. Realizing those differences would be helpful for clinicians to establish an appropriate differential diagnosis and make referral decisions.

In silico screening and molecular dynamics of phytochemicals from Indian cuisine against SARS-CoV-2 MPro

SARS-CoV-2 cause fatal infection in 213 countries accounting for the death of millions of people globally. In the present study, phytochemicals from spices were assessed for their ability to interact with SARS-CoV-2 M^Pro. Structure based virtual screening was performed with 146 phytochemicals from spices using Autodock Vina. Phytochemicals with binding energy ≥ -8.0 kcal/mol were selected to understand their interaction with M^Pro. Virtual screening was further validated by performing molecular docking to generate favorable docked poses and the participation of important amino acid residues. Molecular dynamics simulation for the docked poses was performed to study thermodynamic properties of the protein, ligand and protein-ligand complexes. The finding shows that cinnamtannin B2 and cyanin showed favorable binding affinity values with SARS-CoV-2 M^Pro. The results are comparable in terms of docked poses, important amino acid participation and thermodynamic properties with the standard control drugs remdesivir, benazepril and hydroxychloroquine diphosphate. Prime MM-GBSA was employed for end-point binding energy calculation. Binding to domain I and II of M^Pro were mediated through the OH, SH, NH₂ and non-polar side chain of amino acids. Cinnamtannin B2 and cyanin binds to M^Pro with many sub sites within the active site with RMSD and RMSF within 4 Å. The results computed using Prime MM-GBSA show that cinnamtannin B2 (-68.54940214 kcal/mol) and cyanin (-62.1902835 kcal/mol) have better binding affinity in comparison to hydroxychloroquine diphosphate (-54.00912412 kcal/mol) and benazepril (-53.70242369 kcal/mol). The results provide a basis for exploiting cinnamtannin B2 and cyanin as a starting point potential candidate for the development of drug against SARS-CoV-2.Communicated by Ramaswamy H. Sarma.

Methods for assessing cough sensitivity

Cough sensitivity can be described as the reaction intensity of the cough reflex to different stimuli which activate chemically and mechanically sensitive vagal afferent nerves innervating airways and lungs. Measurement of cough reflex sensitivity plays an important role in revealing the underlying mechanisms of cough and evaluating the effects of pharmacological interventions. Besides, different responses to cough suppression therapies indicate the existence of cough hypersensitivity. In consideration of these factors stated above, cough sensitivity should therefore be assessed with a variety of cough challenge tests. Based on the neuroanatomical characteristics of the cough reflex, chemical challenge tests have been developed to objectively assess cough sensitivity. In cough inhalation challenges, capsaicin and citric acid are commonly used as the tussive agents to induce cough, which are validated for describing a profile of cough sensitivity to chemical irritants. Recently, mechanical methodologies have also been tried to measure the mechanical sensitivity of the cough reflex. Methodological consideration and selection are necessary for the reasonable assessment of cough sensitivity while employing cough challenges in clinical trials. Thus, in this review, we will focus on describing various methodologies of cough sensitivity measurement and, detailing some factors influencing on the accuracy of outcomes in the experimentally induced cough.

Perspectives on chronic cough in Korea

Chronic cough is a common condition, and generally affects about 3% of Korean adults with a significant influence on quality of life (QoL). Despite continued clinical and academic efforts, there are unmet needs for chronic cough prevention and management in Korea. Epidemiologically, there are two major challenges: an aging population and air pollution. Korea is one of the most rapidly aging countries, and the relative proportion of elderly to younger people is expected to double within the next two decades. Air pollution is a major concern, but there is very limited evidence on the effects of air pollutant on cough in Korean patients. Clinically, upper and lower airway diseases, such as rhinitis/rhinosinusitis and cough variant asthma/eosinophilic bronchitis, are reported to account for about 75% of chronic cough in Korean adults, which formed the basis in formulating clinical practice guidelines. However, further studies are warranted to resolve clinical uncertainty, particularly for the evaluation and treatment of upper airway conditions in chronic cough. The prevalence of gastroesophageal reflux disease (GERD) is increasing, thus its relevance to cough among Koreans may warrant re-evaluation. Infection-associated chronic cough, such as tuberculosis, is another continuing concern. The proportion of chronic refractory or unexplained cough is assumed to be 10–20% among patients visiting referral clinics for chronic cough. This review presents our perspectives on current epidemiological and clinical issues of chronic cough in Korea, and addresses major knowledge gaps and future research priorities.

Gabapentin versus baclofen for treatment of refractory gastroesophageal reflux-induced chronic cough

Refractory gastroesophageal reflux-induced chronic cough (GERC) is a special type of gastroesophageal reflux disease (GERD) with predominant cough resistant to pragmatic standard anti-reflux therapy including antisecretory agents alone or in combination with promotility agents but with a favorable response to intensified anti-reflux treatment. The condition is not rare and is difficult to treat. Neuromodulators such as baclofen and gabapentin are considered potential therapeutic options for refractory GERC. Limited data indicate that gabapentin and baclofen could attenuate the cough symptom in patients with refractory GERC by blockade of gastroesophageal reflux or by direct antitussive effects. However, no study has compared the efficacy of these two drugs in treatment of refractory GERC. In an open-labeled randomized clinical study, we demonstrated that, as add-on therapy, gabapentin and baclofen had a similar prevalence of therapeutic success for suspected refractory GERC but gabapentin may be more preferable because of its fewer central side effects. The efficacy of baclofen and gabapentin was suboptimal, so further studies are needed to select the patients with refractory GERC suitable for precise treatment using these two neuromodulators.

The Predicative Clinical Features Associated with Chronic Cough That Has a Single Underlying Cause

Background

Few studies have investigated the usefulness of the clinical characteristics of cough in the diagnosis of chronic cough.

Objective

To evaluate the diagnostic value of clinical characteristics and concomitant symptoms of chronic cough in predicting its cause.

Methods

We recruited adult patients with chronic cough as a primary presenting symptom and identified those with a single underlying cause. Clinical features of cough were recorded with a custom-designed questionnaire and the relationships between clinical features and cause of cough were analyzed.

Results

A total of 1162 patients with a single underlying cause were enrolled. Nocturnal cough alone was a predictor of cough variant asthma (odds ratio [OR], 2.037; 95% CI, 1.003-4.139) with high specificity (97.6%) and low sensitivity (8.1%). Heartburn (OR, 2.671; 95% CI, 1.544-4.620), belching (OR, 2.536; 95% CI, 1.620-3.971), and acid regurgitation (OR, 2.043; 95% CI, 1.299-3.212) indicated gastroesophageal reflux–related cough with high specificity (85.5%-94.9%) and low sensitivity (22.8%-40.7%). Cough after meals had a high specificity (91.2%) and a low sensitivity (24.8%) for gastroesophageal reflux–related cough. Postnasal dripping (OR, 2.317; 95% CI, 1.425-3.767) and history of sinusitis (OR, 4.137; 95% CI, 2.483-6.892) were indicators for upper airway cough syndrome with high specificity (80.8% and 90.2%, respectively). Rhinitis/sinusitis-related symptoms showed moderate sensitivity (72.9%); however, they showed mild specificity (46.1%) for upper airway cough syndrome.

Conclusions

Cough timing, several concomitant symptoms associated with gastroesophageal reflux or rhinitis/sinusitis, and medical history are useful to indicate common causes of chronic cough.

Economic Burden of Pediatric Asthma in Turkey: A Cost of Illness Study from Payer Perspective

OBJECTIVES

To estimate economic burden of pediatric asthma in Turkey from payer perspective.

MATERIALS AND METHODS

This cost of illness study was based on identification of per patient annual direct medical costs for the management of pediatric asthma in Turkey from payer perspective. Average per patient direct medical cost was calculated based on cost items related to outpatient visits, laboratory and radiological tests, hospitalizations and interventions, drug treatment and equipment, and co-morbidities/complications.

RESULTS

Based on total annual per patient costs calculated for outpatient admission ($113.14), laboratory-radiological tests ($35.94), hospitalizations ($725.92), drug treatment/equipment ($212.90) and co-morbidities/complications ($144.62) cost items, total per patient annual direct medical cost related to management of pediatric asthma was calculated to be $1,232.53 from payer perspective. Hospitalizations and interventions (58.9%) was the main cost driver. Direct cost for managing controlled and uncontrolled pediatric asthma were calculated to be $530.17 [key cost driver: drugs/equipment (40.0%)] and $1,023.16 [key cost driver: hospitalization/interventions (59.0%)], respectively.

CONCLUSION

Our findings indicate that managing patients with pediatric asthma pose a considerable burden to health economics in Turkey, with hospitalizations identified as the main cost driver and two-fold cost increment in case of uncontrolled disease.

Coronavirus Disease 2019 (COVID-19) and Transplantation: Pharmacotherapeutic Management of Immunosuppression Regimen

The 2019 novel coronavirus disease (COVID-19) was first detected in Wuhan, Hubei Province, China, in late 2019. Since then, COVID-19 has spread to more than 200 countries in the world, and a global pandemic has been declared by the World Health Organization (WHO). At present, no vaccines or therapeutic regimens with proven efficacy are available for the management of COVID-19. Hydroxychloroquine/chloroquine, lopinavir/ritonavir, ribavirin, interferons, umifenovir, remdesivir, and interleukin antagonists, such as tocilizumab, have been recommended as potential treatment options in COVID-19. Transplant patients receiving immunosuppressant medications are at the highest risk of severe illness from COVID-19. At the same time, with regard to receiving polypharmacy and immunosuppressants, treatment options should be chosen with more attention in this population. Considering drug-drug interactions and adverse effects of medications used for the treatment of COVID-19, such as QT prolongation, the dose reduction of some immunosuppressants or avoidance is recommended in transplant recipients with COVID-19. Thus, this narrative review describes clinically important considerations about the treatment of COVID-19 and immunosuppressive regimens regarding modifications, side effects, and interactions in adult kidney or liver allograft recipients.

Recent progress in the management of chronic cough

Chronic cough is a common clinical condition with significant impact on quality of life and for which effective therapy remains an unmet clinical need. Over the past decade, there has been a major shift in how we approach this problem, driven by better appreciation of the clinical manifestation of chronic cough and an improved understanding of the associated neurobiology. "Cough hypersensitivity syndrome" has been proposed as a new diagnostic term for chronic cough, encompassing different phenotypes of the condition. Accumulating evidence suggests that this new concept is clinically relevant. However, while it is gaining widespread endorsement within the allergy and respiratory community, raising its profile in routine clinical practice is a priority. Thus, the present paper reviews recent progress in our understanding and management of chronic cough, with focus on mechanistic and clinical studies. It also provides detail on knowledge gaps and future research directions.

Duration of treatment with inhaled corticosteroids in nonasthmatic eosinophilic bronchitis: a randomized open label trial

BACKGROUND

Nonasthmatic eosinophilic bronchitis (NAEB) responds well to inhaled corticosteroids (ICS), while recurrence is common after discontinuing treatment. There are no data available to show whether treatment duration of ICS in patients with NAEB is related to recurrence. We aim to evaluate the effect of different duration of treatment with ICS on relapse of NAEB.

METHODS

A total of 101 patients with NAEB were recruited to the open label, randomized, parallel-group trial. Patients were randomized to receive 1-month, 2-month, or 4-month treatment with inhaled budesonide (200 μg, twice daily). Sputum induction, cough visual analogue scale (VAS), and cough symptom score (CSS) were conducted at baseline and after completion of treatment. The patients were followed up for 1 year after treatment. The primary outcome was the relapse rate of NAEB in 1 year.

RESULTS

ICS significantly decreased cough VAS, CSS, and sputum eosinophilia among these groups. There were no statistically significant between-group differences in cough VAS, CSS scores, and sputum eosinophil counts at the end of treatment, and no significant between-group differences in those changes from baseline to post-treatment. Significantly, more participants in the 1-month treatment group experienced a recurring episode of NAEB than those in the 3-month treatment group (41.9% versus 12.0%, p = 0.0137) at 1-year follow-up. The 2-month treatment group showed a lower tendency, with a relapse rate of 20.0% (p = 0.0644).

CONCLUSIONS

Our results suggest that inhaled corticosteroids should be administrated for at least 2 months to reduce the relapse of NAEB.

CLINICAL TRIAL REGISTRATION

The study was registered on ClinicalTrials.gov (NCT02002715). The reviews of this paper are available via the supplemental material section.

In silico identification of potential inhibitors from Cinnamon against main protease and spike glycoprotein of SARS CoV-2

Cinnamon has been utilized to remedy a lot of afflictions of humans. Literary works illustrate that it possesses numerous biological activities. Our research study is intended to recognize the phyto-derived antiviral substances from Cinnamon against COVID-19 main protease enzyme and to understand the in silico molecular basis of its activity. In the present study, 48 isolates compounds from Cinnamon retrieved from the PubMed database, are subjected to docking analysis. Docking study was performed using Autodock vina and PyRx software. Afterwards, admetSAR, as well as DruLiTo servers, were used to investigate drug-likeness prophecy. Our study shows that the nine phytochemicals of Cinnamon are very likely against the main protease enzyme of COVID-19. Further MD simulations could identify Tenufolin (TEN) and Pavetannin C1 (PAV) as hit compounds. Utilizing contemporary strategies, these phyto-compounds from a natural origin might establish a reliable medication or support lead identification. Identified hit compounds can be further taken for in vitro and in vivo studies to examine their effectiveness versus COVID-19.

Diagnoses and management of adult cough: An Indian Environmental Medical Association (EMA) position paper

BACKGROUND

Cough is a common yet distressing symptom that results in significant health care costs from outpatient visits and related consultations.

OBJECTIVE

The understanding of the pathobiology of cough in recent times has undergone an evolution with Cough hypersensitivity syndrome (CHS) being suggested in most cases of dry cough. However, in the case of productive cough, ancillary mechanisms including impaired Mucociliary clearance, in addition to hypermucosecretory bronchospastic conditions of Smoker's cough, asthma-COPD overlap, bronchiectasis, and allergic bronchopulmonary aspergillosis, need to be critically addressed while optimizing patient care with symptomatic therapy in outpatient settings of India.

METHODS

In this review, evidence-based graded recommendations on use of antitussives - & protussives as a Position Paper were developed based on the Level and Quality of Scientific evidence as per Agency for Health Care and Quality (AHRQ) criteria listing and Expert opinions offered by a multidisciplinary EMA panel in India.

RESULTS

Management of acute or chronic cough involves addressing common issues of environmental exposures and patient concerns before instituting supportive therapy with antitussives or bronchodilatory cough formulations containing mucoactives, anti-inflammatory, or short-acting beta-2 agonist agents.

CONCLUSION

The analyses provides a real world approach to the management of acute or chronic cough in various clinical conditions with pro- or antitussive agents while avoiding their misuse in empirical settings.

Elevated Circulating CD4+CD25+CD127-/low Regulatory T Cells in Patients with Non-asthmatic Eosinophilic Bronchitis

PURPOSE

Non-asthmatic eosinophilic bronchitis (NAEB) is a common cause of chronic cough. It is characterized by sputum eosinophilia like asthma but lacks airway hyperresponsiveness. Regulatory T cells (Tregs) are recognized as immune suppressors and are involved in the pathogenesis of asthma. However, the relationship between Tregs and NAEB remains unknown. This study aimed to preliminarily explore the role of Tregs in NAEB by comparing circulating Tregs levels to asthma and healthy controls.

METHODS

Fractional exhaled nitric oxide (FeNO), spirometry with bronchial provocation test, sputum induction and blood routine test were performed in all subjects. Peripheral blood mononuclear cells were used to detect the Tregs (CD4⁺CD25⁺CD127^-/low) by flow cytometry. Relationship between the levels of circulating Tregs and clinical indexes was also observed.

RESULTS

A total of 15 patients with NAEB, 20 patients with asthma and 11 healthy controls were included. The absolute numbers of circulating Tregs in the NAEB group (49.8 ± 18.9 × 10³ cells/ml) and asthma group (53.3 ± 18.7 × 10³ cells/ml) were higher than that in healthy control group (32.7 ± 11.6 × 10³ cells/ml) (both P < 0.01). In total, the level of circulating Tregs showed positive correlation with FeNO (r = 0.30, P < 0.05).

CONCLUSION

Tregs may play a key role not only in asthmatic patients, but also in patients with NAEB, as reflected by the elevated Tregs in peripheral blood.