A comprehensive analysis of the components of common weed pollen and related allergens in patients with allergic diseases in southern China.

BACKGROUND: Pollen allergens are vital contributors to allergic diseases. The frequency and coreactivity pattern of allergens are closely related to geographical distribution. OBJECTIVE: In this study, we aimed to characterize the prevalence of the molecular components of the common weed pollen allergens, birch pollen, walnut, and cross-reactive carbohydrate determinant (CCD), as well as investigate the relationship between the allergens and CCD in Chinese pollen-sensitized patients with allergic diseases. METHODS: Based on previous vegetation surveys, serum samples from 165 pollen-sensitized patients with allergic diseases in Guangdong Province in southern China were used to test 19 crude allergen extracts, their components, and CCD using component-resolved diagnosis (CRD). Moreover, the potential associations among CCD, allergens, and their components were described. RESULTS: In the 165 samples, the most common sensitized allergens were goosefoot (43.0%), ragweed (40.6%), walnut (37.6%), walnut tree (37.6%), and mugwort (37.0%), followed by platane (35.2%), cocklebur (27.9%), and birch (24.2%). The positivity rate of CCD was 39.4%. Among the samples positive for mugwort, 11 (18.0%), 15 (24.6%), and 15 (24.6%) were positive for Art v 1, Art v 2, and Art v 3, respectively. Among the 67 patients sensitized to ragweed, only five (7.5%) were positive for Amb a 1. In the 40 patients sensitized to birch, Bet v 2 had the highest positivity rate (40.0%). There were 62 patients who were sensitized to walnut. Their components had a lower positivity rate (less than 15%). The hierarchical clustering and optimal scale analysis showed that Art v 4 and Bet v 2 were closely related, and 91.9% of CCD-positive samples were polysensitized. Meanwhile, Spearman's rank correlation method showed that CCD was closely correlated with the sensitization of crude allergen extracts, and there was a low correlation between CCD and allergen components. CCD was highly correlated with goosefoot, ragweed, and walnut trees (r＞0.8). Moreover, there was a strong relationship between the levels of Jug r 3 and Art v 3 (r = 0.78; P < 0.001). CONCLUSIONS: In southern China, the weed pollens (ragweed, cocklebur, and goosefoot) exhibited higher positivity rates in adults and had a stronger relationship with CCD but not with mugwort. The positivity rate of allergen components was not high. CCD-positive samples were always polysensitized.

Fractional Exhaled Nitric Oxide (FeNO) Integrating Airway Hyperresponsiveness (AHR) Examination Promotes Etiologic Diagnosis and Treatment for Children with Chronic Cough.

BACKGROUND Chronic cough is the main reason why parents seek medical treatment for their children. This study aimed to evaluate changes in airway function and inflammation levels and associated values in diagnosing and treating chronic cough. MATERIAL AND METHODS This study involved 118 children with chronic cough, including 45 cough-variant asthma (CVA) patients, 53 upper-airway cough syndrome (UACS) patients, and 20 post-infection cough (PIC) patients. Chronic cough was diagnosed as described by guidelines of the American College of Chest Physicians for evaluating chronic cough. Pulmonary ventilation function and airway hyperresponsiveness (AHR) were evaluated. Fractional exhaled nitric oxide (FeNO) levels and eosinophilic airway inflammation were measured. Eosinophil (EOS) count in sputum was also examined. CVA patients were treated with inhaled glucocorticoids, which have anti-inflammatory effects. RESULTS FeNO and sputum EOS levels were higher in CVA patients compared with UACS and PIC patients (P<0.05). CVA patients demonstrated significantly higher small airway indexes, including 25% forced expiratory flow (FEF), 50% FEF, and 75% FEF, compared with UACS and PIC patients (P<0.05). FeNO level was positively correlated with EOS in sputum (r=0.468, P=0.0001) and cough symptom scores (r=0.402, P<0.05). FeNO, EOS, and cough symptoms were significantly improved in CVA patients after glucocorticoid treatment. AHR was improved in all chronic cough patients after treatment. Cough-relief CVA patients demonstrated significantly higher FeNO levels compared with those without cough relief (P<0.05). CONCLUSIONS FeNO integrating pulmonary function and AHR examination can improve etiologic diagnosis and treatment for chronic cough in children.

Etiologies associated with chronic cough and its clinical characteristics in school-age children.

BACKGROUND: To comprehensively evaluate the etiology of chronic cough and the value of clinical feature in school age children in Suzhou, China. METHODS: School-age (6-14 years) children newly referred with chronic cough (>4 weeks) were prospectively evaluated by utilizing a diagnostic algorithm in this study. Clinical features of different etiologies of chronic cough were also investigated. RESULTS: In total, 118 patients were enrolled in the study. The cough duration ranged from 1 to 76 months. Upper airway cough syndrome (UACS) was found in 77 (65.3%) patients with chronic cough, cough-variant asthma (CVA) in 57 (48.3%) patients, protracted bronchitis (PB) in 15 (12.7%) patients, gastroesophageal reflux disease (GERD) in 7 (5.9%) patients, tic disorders (TD) in 3 (2.5%) patients and eosinophilic bronchitis (EB) in 2 (1.7%) patients. A single etiology was present in 75 patients and multiple etiologies were present in 43 patients. The three most common single etiologies were UACS (31.4%), CVA (14.4%), and PB (10.2%), followed by GERD (5.9%), and EB (1.7%). The most common multiple etiology was CVA + UACS (31.4%), followed by CVA + PB (2.5%), and TD + UACS (2.5%). CONCLUSIONS: The common etiologies of chronic cough in school-age children were UACS, CVA, and PB, while EB and GERD were rare.

Fractional Exhaled Nitric Oxide (FeNO) Combined with Pulmonary Function Parameters Shows Increased Sensitivity and Specificity for the Diagnosis of Cough Variant Asthma in Children.

BACKGROUND Cough variant asthma in children presents with a dry nonproductive cough. This study aimed to investigate the diagnostic value of fractional exhaled nitric oxide (FeNO) combined with small airway functional parameters in cough variant asthma. MATERIAL AND METHODS Children with asthma (n=136) were divided into a cough variant asthma (CVA) group (n=57; mean age, 8.03±2.1 years) and a non-cough variant asthma (nCVA) group (n=79; mean age, 8.61±1.7 years). In both groups, FeNO and other pulmonary function parameters were measured including forced expiratory volume in one second (FEV1), forced vital capacity (FVC), peak expiratory flow (PEF), maximum mid-expiratory flow (MMEF), forced expiratory flow (FEF), and maximum expiratory flow at 25%, 50%, and 75% expired volume (MEF25, MEF50, and MEF75). Receiver-operating characteristic (ROC) curve analysis compared the sensitivity and specificity between the diagnostic parameters. RESULTS The FeNO values were significantly increased in the CVA group compared with the nCVA group (Z=6.890, p<0.001). The MMEF, MEF25, MEF50, and MEF75 values were significantly lower in the CVA group compared with the nCVA group (p=0.000, p=0.014, p=0.000, and p=0.000, respectively). The FeNO values were negatively correlated with MEF25, MEF50, and MMEF (ρ=-0.334, ρ=-0.257 and ρ=-0.276, respectively). FeNO was significantly more efficient diagnosing cough variant asthma comparing with pulmonary parameters (p<0.05), and was most sensitive and specific when combined with MMEF/MEF50 compared with single diagnostic parameters (p<0.05). CONCLUSIONS FeNO combined with pulmonary function parameters of MMEF/MEF50 showed increased sensitivity and specificity for the diagnosis of cough variant asthma.

Values of fractional exhaled nitric oxide for cough-variant asthma in children with chronic cough.

BACKGROUND: Chronic cough is a common symptom in children. We wished to explore the value of fractional exhaled nitric oxide (FeNO) for cough-variant asthma (CVA) in children with chronic cough. METHODS: This prospective cohort study was conducted in the Children's Hospital of Soochow University from January 2012 to December 2014. Children aged 6-14 years with a cough of duration >4 weeks were enrolled. They underwent FeNO measurement, sputum cytology and pulmonary function tests. RESULTS: A total of 115 patients and 25 healthy controls were evaluated. For the diagnosis of CVA, the optimal FeNO cutoff value was 25 ppb with a sensitivity of 84.0%, specificity of 97.1%, positive predictive value of 97.5%, and negative predictive of being 81.4%. The FeNO level had a significant correlation with eosinophil count in sputum (P<0.05). FeNO level in CVA was decreased significantly after treatment (P=0.001). CONCLUSIONS: In children, FeNO measurement might be an excellent method for diagnosing CVA with high sensitivity and specificity.

[The diagnostic value of the fractional exhaled nitric oxide for cough variant asthma in children].

OBJECTIVE: To determine the diagnostic value of fractional exhaled nitric oxide (FeNO) measurement in diagnosis of Cough Variant Asthma (CVA) in children. METHODS: Outpatients with a cough > 4 weeks visiting The Children's Hospital Affiliated to Suzhou University from March 2012 to April 2013 were enrolled. FeNO was measured by a nitric oxide analyzer in accordance with American Thoracic Society guidelines. The levels of FeNO in CVA and other causes of chronic cough were compared. The value of FeNO was assessed and the optimal operating point of FeNO testing for the diagnosis of CVA was determined by the means of the receiver operating characteristic (ROC) curves. RESULTS: A total of 84 children with chronic cough were recruited, among whom 38 were diagnosed as having CVA. The levels of FeNO were not statistically different between patients with CVA [(37.2 ± 13.8) ppb] and patients with CVA combined with upper airway cough syndrome [UACS, (40.1 ± 13.8) ppb, P = 0.124], but were both significantly higher than those in patients with UACS or with postinfectious cough (PIC), and the normal control group (P < 0.01 respectively). There were 46 non-CVA patients, including 34 cases with UACS and 12 PIC, and their FeNO levels were not statistically different [(18.3 ± 7.6) to (19.2 ± 4.4) ppb, t = 2.580, P = 2.996]. The levels of FeNO declined rapidly in CVA patients after inhaled corticosteroids during the 4 week follow-up. The proportion of eosinophils in the sputum from CVA patients was higher than that from the non-CVA patients, consistent with the level of FeNO, which showed a positive linear correlation with sputum eosinophils. The area under ROC curve was 0.94.The optimal diagnostic cutoff point was 22.5 ppb which was capable of differentiating CVA and non-CVA with a sensitivity of 84%, and a specificity of 94.3%. CONCLUSIONS: The level of FENO was higher in CVA compared to other causes of chronic cough. FeNO, a marker of airway eosinophilic inflammation, may be helpful in the diagnosis of CVA in children with high sensitivity and specificity.

Clinical characteristics of protracted bacterial bronchitis in Chinese infants.

Protracted bacterial bronchitis (PBB) is the common cause of chronic cough in children worldwide, but its etiology has not been fully recognized in China. We retrospectively investigated a total of 66 hospitalized infants under the age of three years with chronic wet cough enrolled in the Affiliated Children's Hospital of Soochow University from October 2010 to March 2014. All patients underwent bronchoscopy and broncho-alveolar lavage (BAL) samples were processed for microbiological and cytological analysis. Of 66 patients with wet cough, 50 (75.8%) were diagnosed with PBB. In the PBB group, wet cough was accompanied by wheezing (90%). Airway malacia were identified in 22 cases (44%). The clinical manifestations of PBB with airway malacia did not differ from those without malacia. Haemophilus influenzae (47.4%) and Streptococcus pneumoniae (36.8%) were the most commonly identified pathogens. Furthermore, CD3(+) and CD3(+)CD4(+) cells were significantly lower in the PBB group (p < 0.01), while CD19(+), CD16(+)CD56(+) and CD23(+) cells were elevated (p < 0.01) in the PBB group. Our study revealed PBB is an important cause of chronic wet cough in Chinese infants, and that changes of lymphocyte subsets are observed in children with PBB. Airway malacia frequently co-existed with PBB, but did not exacerbate the disease.

[Characteristics of airway hyperresponsiveness in children with chronic cough of different causes].

OBJECTIVE: To study the characteristics of airway hyperresponsiveness in children with different causes of chronic cough. METHODS: A prospective study was conducted in children suffering from chronic cough caused by a single reason at the department of respirology of Children's Hospital of Soochow University from April 2012 to December 2013. Bronchial provocation test, induced sputum eosinophil count, and exhale nitric oxide were detected at beginning and 4 weeks later. The severity of the CVA was classified according to the integral dose of histamine which resulted in a 20% (PD20) fall in forced expiratory volume in 1 s (FEV1). All patients received treatment according to the recommended guidelines for chronic cough in children of China. According to the responses to the treatment and the results of physical examinations and laboratory findings, a final diagnosis was confirmed. RESULTS: A total of 66 children were enrolled in this study, including cough variant asthma (CVA)in 17, upper airway cough syndrome (UACS) in 37, and post infection cough (PIC) in 12 cases. Positive AHR in CVA, UACS, and PIC groups was found in 17, 13, and 9 cases respectively at the first visit, and after 4 weeks, it was found in 17, 5, and 2 cases respectively. The severity of AHR in CVA, UACS and PIC at beginning and after 4 weeks were moderate to severe in 5, 0, 0 cases and 1, 0, 0 case; Mild to very mild in 12, 13, 9 cases and 16, 5, 2 cases.Negative response was found in 0, 24, 3 cases and 0, 32, 10 cases, respectively. The values of PD20 in CVA group (0.47 ± 0.28) mg were statistically lower those in UACS group (1.8 ± 0.64) mg and PIC group (1.2 ± 0.80) mg (P < 0.01) . The sputum eosinophil count was > 3% in all cases of CVA but all <3% in UACS and PIC.FeNO and sputum eosinophil counts were positively correlated (r = 0.687, P = 0.000) . CONCLUSION: The characteristics of airway responsiveness of chronic cough caused by different causes were varied in different AHR severity and course. Bronchial provocation test combined with induced sputum showed certain values for confirming the cause of chronic cough in children.

[Clinical features of protracted bacterial bronchitis in children].

OBJECTIVE: To analyze the clinical characteristics of protracted bacterial bronchitis (PBB) in children. METHOD: The clinical data of patients seen from October, 2010 to March, 2014 in Department of Respiratory Diseases of our hospital were retrospectively analyzed. Inclusion criteria were over 4 weeks cough, receiving fiberoptic bronchoscopy, positive bacterial culture and (or) the increased percentage of neutral granulocytes in bronchoalveolar lavage fluid (BALF). RESULT: Twenty eight patients were involved, 26 were male (93%) and two were female (7%). The median age of patients was 8.5 months. The median duration of cough was four weeks. The average length of hospital stay was (8.3 ± 3.9)days. The main clinical feature was wet cough in 28 cases, wet cough with wheezing was seen in 21 cases. The wet cough phase distribution was irregular in 21 cases. The crackles with wheeze (in 21 cases) was main signs of PBB. The percentage of CD3⁻ CD16⁺ 56⁺ cells increased in peripheral blood. The fiberoptic bronchoscopic manifestations of PBB were luminal mucosal edema. Eleven patients also had airway malacia. The neutrophil median in BALF was 0.2. The positive rate of bacterial culture of BALF was 36%. The main bacteria were Streptococcus pneumoniae (50%) and Haemophilus influenzae (30%). The main treatment for PBB patients included amoxycillin/clavulanate potassium and second-generation cephalosporins. The average duration of treatment was (17.3 ± 3.2)days, the prognosis was good. CONCLUSION: PBB is common in male infants. Persistent wet cough with wheezing was the main characteristic of PBB. PBB is commonly accompanied by immune dysfunction and airway malacia, and the pathogens were Streptococcus pneumoniae and Haemophilus influenzae.

[Study on dynamic changes of airway hyperresponsiveness in children with cough variant asthma].

OBJECTIVE: To explore the dynamic changes of airway hyperresponsiveness (AHR) in children with cough variant asthma (CVA). METHODS: A prospective observational study was conducted at the Children's Hospital of Soochow University from April 2012 to March 2013. A total of 36 patients were diagnosed as CVA. According to the integral dose of histamine resulting in a 20% (PD20) fall in forced expiratory volume in 1 s (FEV1), the severity of CVA was graded. Corresponding treatment was administered and the dynamic changes of airway hyperresponsiveness were followed for 0, 1 and 6 months. RESULTS: Among them, 14 patients suffered from CVA only while another 22 cases had CVA plus upper airway cough syndrome (UACS). PD20 of CVA and CVA+UACS groups were (0.46 ± 0.26) and (0.58 ± 0.34) mg respectively. No statistically significance existed between two groups (t = -0.880, P > 0.05). According to the value of PD20, AHR in CVA patients was classified into four degrees of severe, moderate, mild and very mild. Initially there were moderate (n = 8), mild (n = 21) and very mild (n = 5). At 1 month follow-up, moderate (n = 1), mild (n = 28) and borderline (n = 7); At 6 month, moderate (n = 2), mild (n = 20) and very mild (n = 7). And 4 cases turned negative and another 3 cases became lost. Cough symptom score and PD20 showed no significant correlation (r = -0.086, P > 0.05). CONCLUSIONS: AHR in CVA patients is predominantly mild and very mild. And it decreases rapidly mostly during initial treatment phase. The proportion of conversion from CVA into negative and typical bronchial asthma is relatively low.