• Clinical and Experimental Pediatrics
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• v.49 no.11
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• pp.1216-1222
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• 2006

Purpose : Though atopic and nonatopic asthma have different clinical manifestations, bronchial hyperresponsiveness (BHR) and airway inflammations are common characteristics of them. We investigated BHR to both methacholine and adenosine 5'-monophosphate (AMP), and their relationships with blood eosinophil markers in nonatopic asthma as well as atopic asthma. Methods : We studied 116 children (82 atopics; 34 nonatopics) with mild to moderate asthma. Methacholine and AMP challenge tests were performed and bronchial responsiveness was expressed as $PC_{20}$ (provocative concentration causing a 20 percent fall in $FEV_1$); blood eosinopil counts (ETCs) and serum eosinophil cationic protein (ECP) levels were gauged. Results : In atopics, 95.1 percent and 90.2 percent showed hyperreactivity to methacholine ($PC_{20}$<16 mg/mL) and AMP ($PC_{20}$<200 mg/mL), respectively. Meanwhile, in nonatopics, 94.1 percent and 52.9 percent displayed hyperreactivity to methacholine and AMP, respectively. The geometric mean of AMP $PC_{20}$ was lower in atopics (31.6 mg/mL) than in nonatopics (125.9 mg/mL); that of methacholine $PC_{20}$ was similar in the two groups. AMP $PC_{20}$ correlated with blood ETCs in both atopics(r=-0.30, P<0.01) and nonatopics (r=-0.57, P<0.01), and correlated with serum ECP levels (r=-0.23, P<0.01) in atopics, but not in nonatopics. Apart from AMP, methacholine $PC_{20}$ was not associated with blood eosinophil markers in either group. Conclusion : Atopics more frequently displayed BHR to AMP than nonatopics. Furthermore, BHR to AMP was associated with not only blood ETCs, but serum ECP levels in atopics but was correlated with only blood ETCs in nonatopics. Those results suggest that BHR to AMP reflects airway inflammation in asthma and is more related to atopy.

• Clinical and Experimental Pediatrics
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• v.57 no.1
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• pp.29-34
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• 2014

Purpose: In this study, we aimed to investigate the prevalence of year-round respiratory viral infection in children with lower respiratory tract infection (LRTI) and the relationship between respiratory viral infection and allergen sensitization in exacerbating asthma. Methods: We investigated the sources for acute LRTIs in children admitted to our hospital from May 2010 to April 2011. The 6 most common respiratory viruses were isolated from nasopharyngeal aspirate using multiplex reverse transcription-polymerase chain reaction in 309 children; respiratory syncytial virus (RSV), adenovirus (AV), parainfluenza virus (PIV), influenza virus (IFV), human metapneumovirus (hMPV), rhinovirus (RV). Atopic sensitization was defined if more than 1 serum specific Immunoglobulin E level measured using UniCAP (Pharmacia) was over 0.35 IU/mL. Results: RSV was the most common pathogen of bronchiolitis in hospitalized children through the year. RV or IFV infection was more prevalent in asthma exacerbations compared to other LRTIs. AV and hMPV were more likely to cause pneumonia. RV and IFV were associated with asthma exacerbations in children with atopic sensitization, but not in nonatopic children. Conclusion: RV and IFV are associated with hospitalization for asthma exacerbation in children with atopic sensitization.

• Clinical and Experimental Pediatrics
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• v.46 no.3
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• pp.284-290
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• 2003

Purpose : A new airway inflammatory marker, exhaled nitric oxide(ENO) has been reported to correlate with bronchial hyperresponsiveness(BHR) and atopy. The purpose of this study was to analyze the relationship of ENO with BHR or atopy in patients with asthma and with allergic rhinitis. Methods : The subjects consisted of 55 children with asthma, 17 with allergic rhinitis, and 14 healthy controls. The asthma group was subdivided into the atopic asthma group(n=37) and the nonatopic asthma group(n=18) and the allergic rhinitis group into BHR group(n=7) and non-BHR group(n=10). All were investigated with spirometry and measurements of ENO concentration. The correlations between ENO concentration and both methacholine $PC_{20}$(provocative concentration causing a 20% decrease in forced expiratory volume in one second) and the number of allergen skin test positivity were analyzed. Results : ENO concentrations of both asthma and allergic rhinitis groups were significantly greater than that of control(P<0.01). ENO concentration of atopic asthma was significantly greater than that of nonatopic asthma(P<0.01). In allergic rhinitis, ENO concentration did not differ according to the presence or absence of BHR(P=0.50). ENO concentrations correlated significantly with the number of skin test positivity(r=0.32, P=0.02) or methacholine $PC_{20}$(r=-0.38, P<0.01) in asthma group, but not in the allergic rhinitis group(r=0.42, P=0.09; r=-0.06, P=0.83). Conclusion : In asthma patients, some pathogenetic mechanisms associated with atopy and BHR seem to influence ENO concentration. In allergic rhinitis patients, some factors other than BHR may be important in determining ENO concentration.