Ruchong Chen

A Prospective, Multicenter Survey on Causes of Chronic Cough in China

BACKGROUND The causes of chronic cough in China and its relations with geography, seasonality, age, and sex are largely uncertain. METHODS A prospective, multicenter survey was conducted to evaluate patients with chronic cough across five regions in China by using a modified diagnostic algorithm. The effects of geography, seasonality, age, and sex on spectrum of chronic cough were also investigated. RESULTS The current study evaluated 704 adult patients, including 315 men (44.7%) and 389 women (55.3%). The causes of chronic cough were determined in 640 subjects (90.9%). Common causes included cough variant asthma (CVA) (32.6%), upper airway cough syndrome (UACS) (18.6%), eosinophilic bronchitis (EB) (17.2%), and atopic cough (AC) (13.2%). Collectively, these four causes accounted for 75.2% to 87.6% across five different regions without significant difference (P > .05), although there was variation on single causes. Gastroesophageal reflux-related cough was identified in 4.6% of causes. Seasonality, sex, and age were not associated with the spectrum of chronic cough (all P > .05). CONCLUSION CVA, UACS, EB, and AC were common causes of chronic cough in China. Geography, seasonality, age, and sex were not associated with the spectrum of chronic cough.

Will Nonasthmatic Eosinophilic Bronchitis Develop Into Chronic Airway Obstruction?: A Prospective, Observational Study

OBJECTIVE The long-term prognosis of nonasthmatic eosinophilic bronchitis (NAEB) is still unclear. The aim of this study was to observe the frequency of relapse among patients with NAEB and the likelihood of NAEB developing into chronic airflow obstruction over time. METHODS Patients with NAEB were followed for at least 1 year between 2003 and 2013. During this period, we evaluated clinical symptoms, sputum eosinophil count, spirometry, and bronchial hyperresponsiveness. A linear mixed model was adopted to determine the relationship between time and lung function. RESULTS A total of 234 patients with NAEB were identified, of whom 141 were followed for > 1 year (median, 4.1 years). Up to 59.6% of patients had a relapse after treatment. Both allergic rhinitis (OR, 4.37; 95% CI, 1.049-18.203; P = .043) and sputum eosinophilia after 4 weeks of treatment with inhaled corticosteroids (OR, 9.493; 95% CI, 2.381-37.850; P = .001) were risk factors for relapse. Among the 141 patients, mild asthma developed in eight (5.7%). During the follow-up period, no progressive decline in FVC, FEV1, and FEV1/FVC were observed (P > .05). Although the proportion of small airway dysfunction (maximum midexpiratory flow [MMEF] < 65%) significantly increased at the last visit in all groups (all P < .05), only the relapse group showed an MMEF decline at the end of follow-up (P < .05) in the linear mixed model. CONCLUSIONS More than 50% of patients with NAEB have repeated episodes associated with persistent sputum eosinophilia after treatment and allergic rhinitis. In the current cohort, chronic airway obstruction does not develop despite small airway dysfunction increases over time.

Epidemiology of cough in relation to China.

Cough is one of the most common complaints for which patients seek medical attention. Misdiagnosis and mistreatment of cough exist commonly in China. The prevalence of acute cough caused by upper airway infection fluctuates between 9% and 64% in the community, for chronic cough, the prevalence >10% in most surveys, ranging from 7.2%-33%. The common causes of chronic cough are upper airway cough syndrome (previously called as post nasal drip syndrome [PNDS]), cough variant asthma (CVA), gastroesophageal reflux related cough (GERD) and eosinophilic bronchitis (EB). There is a regional discrepancy regarding the prevalence of common causes of cough and distribution of gender among China, UK, USA, the most common cause of chronic cough in China are CVA, followed by UACS, EB and atopic cough (AC), the male is almost equal to female in numbers in China. The risk factors for cough includes cold air, smoking, environmental pollutants, noxious substances and allergens, and unreasonable diet habits.

Validity of Fractional Exhaled Nitric Oxide in Diagnosis of Corticosteroid-Responsive Cough

BACKGROUND Whether fractional exhaled nitric oxide (FeNO) measurement alone or combined with sputum eosinophil and atopy is useful in predicting corticosteroid-responsive cough (CRC) and non-CRC (NCRC) is not clear. METHODS A total of 244 patients with chronic cough and 59 healthy subjects as control were enrolled. The causes of chronic cough were confirmed according to a well-established diagnostic algorithm. FeNO measurement and induced sputum for differential cell were performed in all subjects. RESULTS CRC occurred in 139 (57.0%) patients and NCRC occurred in 105. The FeNO level in CRC significantly correlated with sputum eosinophils (rs = 0.583, P < .01). The median (quarter) of FeNO level in CRC was significantly higher than NCRC (32.0 ppb [19.0-65.0 ppb] vs 15.0 ppb [11.0-22.0 ppb], P < .01). FeNO of 31.5 ppb had a sensitivity and specificity of 54.0% and 91.4%, respectively, in predicting CRC from chronic cough, with a positive predictive value of 89.3% and a negative predictive value of 60.0%. If the patients had a combination of low level of FeNO ( < 22.5 ppb), normal sputum eosinophil ( < 2.5%), and absence of atopy, the sensitivity and specificity would be 30.3% and 93.5% for predicting NCRC. CONCLUSIONS In our cohort, a high level (≥ 31.5 ppb) of FeNO indicates more likelihood of CRC, but the sensitivity is insufficient to rule out a diagnosis of CRC. A combination of low-level FeNO, normal sputum eosinophil, and absence of atopy suggests a lower likelihood of CRC.

Cough reflex sensitivity is increased in guinea pigs with parainfluenza virus infection

ABSTRACT The purpose of this study was to investigate for the change in cough reflex sensitivity (CRS) caused by parainfluenza virus type 3 (PIV3) infection. Guinea pigs were randomized into a vehicle control, an asthma control, or 1 of 4 PIV3-inoculated groups (referred to as postinfection day [PID] 6, 12, 28, and 42 groups). Evidence of viral protein and nucleic acid within the lung confirmed successful PIV3 infection. Plethysmography was used to assess CRS and airway reaction and airway inflammation was assessed via bronchoalveolar lavage fluid cytology and lung histopathology. Compared with the vehicle control group, CRS was significantly increased in all PID groups (P <.05) in concert with an obvious airway hyperresponsiveness in the PID 6 group. Though a small increase in CRS in the asthma control group was noted, it was not significant compared to the vehicle control group. Total cell counts from the bronchoalveolar lavage fluid of all PIV3-inoculated groups increased markedly and the number of lymphocytes was significantly increased in the PID 6 and PID 12 groups. The lung pathology of PIV3-inoculated animals showed airway inflammation without pneumonia in the acute infectious phase. The temporal and spatial variation of CRS may be the essential mechanism of cough caused by PIV3.

Eosinophilic airway inflammation is common in subacute cough following acute upper respiratory tract infection.

Patients presenting with refractory postinfectious cough may respond to glucocorticosteroids but it is unclear whether airway eosinophilic inflammation exists in those patients. We aimed to determine the airway inflammation and causes of subacute cough following acute upper respiratory tract infection (AURTI).

Eotaxin and Il-4 levels are increased in induced sputum and correlate with sputum eosinophils in patients with nonasthmatic eosinophilic bronchitis

Abstract Nonasthmatic eosinophilic bronchitis (NAEB) is characterized by chronic cough and airway eosinophilic inflammation. Airway and systemic inflammation cytokine profile have not been comprehensively described in patients with NAEB. The aim of the study was to identify the cytokine profile in sputum and serum of NAEB patients. Furthermore, the relationship between cytokines and clinical features would be evaluated. Induced sputum and serum were collected from untreated NAEB patients and healthy subjects. The cytokine profile in sputum and serum was analyzed by a bead-based multiplex cytokine assay including 21 cytokines. The levels of EGF, eotaxin, GM-CSF, GRO, IFN-&ggr;, IL-1&bgr;, IL-4, IL-6, IL-17A, IP-10, MIP-1&agr;, and TNF-&agr; in sputum were significantly higher in NAEB patients than that in healthy subjects (all P < 0.05). Values of area under the receiver operating characteristic curve (AUROC) of these cytokines were all above 0.750. The concentrations of eotaxin and IL-4 were positively correlated with sputum eosinophil percentage (r = 0.726, P = 0.002; r = 0.511, P = 0.043; respectively). No significant correlations between other cytokines (EGF, GM-CSF, GRO, IFN-&ggr;, IL-1&bgr;, IL-6, IL-17A, IP-10, MIP-1&agr;, and TNF-&agr;) in sputum and sputum eosinophil percentage were found. The level of IL-4 in serum was slightly higher in NAEB patients than in healthy subjects. However, there was no correlation between serum IL-4 levels and sputum eosinophil percentage. We identified the cytokine profile in sputum and serum from NAEB patients. Sputum eotaxin and IL-4 could have the potential to become the biomarkers for NAEB and might be useful to assist in the diagnosis of NAEB.

Reference Values of Induced Sputum Cytology in Healthy Children in Guangzhou, Southern China

OBJECTIVE: To establish normal reference values of induced sputum cytology in healthy children in southern China. METHODS: During a period from January 2010 to December 2011, a total of 580 healthy children (5–16 years of age) were approached. A total of 266 children (137 boys and 129 girls) participated in the study. Sputum induction was carried out by using 5% hypertonic saline. Cell types in the sputum were examined by using routine methods. RESULTS: Sputum induction was completed in 175 of the 266 subjects (65.79%), but 16 sputum samples were disqualified. The overall success rate was 59.77% (159/266). Macrophages and neutrophils were the predominant cell types: macrophages: median, 76.14%; interquartile range (IQR), 32.68%; and 2.5% to 97.5% percentile, 1.00% to 94.50%; neutrophils: median, 20.67%; IQR, 33.0%; and 2.5% to 97.5% percentile, 4.00% to 92.75%; eosinophils: median, 0.39%; IQR, 1.93%; and 2.5% to 97.5% percentile, 0.00% to 6.50%; and lymphocytes: median, 1.22%; IQR, 2.04%; and 2.5% to 97.5% percentile, 0.00% to 5.00%. The cell types did not differ among different age, gender, and passive smoking groups. Adverse events occurred in 4.4% (7/159) of the participants who completed the procedures but required no specific treatment to dissipate. Peak expiratory flow did not differ between those who completed the procedures compared with those who did not, suggesting that the procedure is safe and feasible in children. CONCLUSIONS: The current study represents the first attempt to develop normal reference values of induced sputum cytology in Chinese children, and could be used as a control for future studies.

The duration of cough in patients with H1N1 influenza

Cough is one of common symptoms of influenza, the cough duration and prevalence of postinfectious cough (PIC) after viral upper respiratory tract infection has not been well described.

Reference value of induced sputum cell counts and its relationship with age in healthy adults in Guangzhou, Southern China

To establish the reference value of total and differential cell counts in induced sputum in healthy adults in Guangzhou, and to explore the relationship of age and gender with sputum cell counts.