Clinical effect of montelukast in exercise-induced asthma / 천식및알레르기

BACKGROUND: Patients with bronchial asthma frequently have exercise-induced bronchocon striction. Exercise-induced bronchoconstriction limits the activities important for physical and social development in children. Leukotriene receptor antagonist has been shown to protect against exercise-induced bronchoconstriction. The purpose of this study is to determine the effect of montelukast in protecting or controlling exercise-induced asthma. METHOD: 22 patients were enrolled and received montelukast(5 mg/day) for 2 months. Exercise challenges were performed before and after treatment and medication was not given for at least 48 hours before follow-up test. The form of exercise was free running for 8 minutes. The respiratory symptom scores, maximum percent fall in FEV1 from pre-exercise baseline and time to recovery of FEV1 to within 10% of pre-exercise baseline were evaluated. RESULTS: The respiratory symptoms score was siginificantly improved after 2 months of therapy(p<0.05). The maximum percent fall in FEV1 after exercise and the time from maximum percent fall in FEV1 to return to within 10 precent of pre-exercise FEV1 were also siginificantly improved after 2 months of therapy(p<0.05). In 3 patients with exercise-induced asthma, the maximum percent fall in FEV1 was decreased after 2 months of therapy, but was increased after follow-up 2 months without therapy. CONCLUSION: Montelukast, a leukotriene-receptor antagonist, is effective for protection and control of exercise-induced asthma in children.

Beta2-adrenoceptor Polymorphisms between Asthmatic and Normal Children in Korea / 소아알레르기및호흡기학회지

BACKGROUND: The role of beta2-agonist is still important to control bronchoconstriction in asthma. Polymorphisms at aminoacid positions 16 and 27 of the beta2-adrenoceptor gene are associated with asthma phenotype. Glu 27 allele is associated with negatively with bronchial hyperresponsiveness(BHR) in asthmatic subjects and Gln 27 allele is associated positively with IgE levels, and Gly16 Gln27 haplotype is suggested to be positively associated with BHR in a population study. And Gly16 Gln27 haplotypes are positively associated with nocturnal cough in atopic subjects. To evaluate the association between beta2-adrenoceptor polymorphisms as asthmatic phenotypes, the frequency of beta2-adrenoceptor polymorphsisms at 2 sites(Arg16->Gly 16 and Gln 27 -> Glu 27) were examined in asthmatic and normal children. METHODS: Ninty nine asthmatic children and seventy three normal children were enrolled. Asthma phenotypes were determined by physician and bronchial responsiveness and genotypes of beta2-adrenoceptor polymorphisms were determined with PCR based methods. RESULTS: The polymorphisms at aminoacid 16 and 27 of beta2-adrenoceptor gene was not different between asthmatic and normal children. The haplotype frequency of aminoacid 16 and 27 polymorphisms of beta2-adrenoceptor gene was not different between asthmatic and normal children. Haplotypes of aminoacid 16 and 27 was not associated with total eosinophil count, eosinophil %, and total IgE in asthmatic children. Haplotypes of aminoacid 16 and 27 was not associated with PC20, and response of FEV1 after beta2-agonist in asthmatic children. CONCLUSION: beta2-adrenoceptor polymorphisms is not associated with the expression of asthma, atopy, bronchial hyperresponsiveness, and response to beta2-agonist in Korean children.