Leukotrienes C4 synthase와 cysteinyl leukotriene receptor 1 유전자 다형성과 한국 소아 천식 표현형 및 임상 지표와의 연관성 연구

Purpose : Cysteinyl leukotrienes are important proinflammatory mediators in asthma. Recently, it was suggested that a promoter polymorphism in the genes encoding for leukotriene C4 synthase (LTC4S), a key enzyme in the leukotriene synthetic pathway, and cysteinyl leukotriene receptor 1 (CysLTR1) might be associated with aspirin-intolerant asthma. We investigated whether polymorphisms in LTC4S and CysLTR1 genes or their interactions were associated with the asthma phenotype, lung function, or bronchial hyperreactivity (BHR) in Korean children. Methods : A total of 856 asthmatic children and 254 non-asthmatic controls were enrolled; a skin prick test, lung function test and bronchial provocation test were performed. Of those enrolled, 395 children underwent exercise challenge tests. The LTC4S A(-444)C and CysLTR1 T(＋927)C were genotyped by polymerase chain reaction-restriction fragment length polymorphism analysis. Results : Of those enrolled, 699 children were classified as having atopic asthma and 277 children, as having exercise-induced asthma (EIA). LTC4S and CysLTR1 polymorphisms were not associated with atopic asthma, EIA, or asthma per se. Lung function and BHR were not significantly different between the wild type (AA or TT) and the variant (AC＋CC or TC＋CC) genotypes in asthmatics, atopic asthmatics, and EIA (＋) asthmatics, while total eosinophil counts were higher in the variant type of LTC4S than in the wild type in atopic asthmatics. There were no associations between the gene-gene interactions of LTC4S and CysLTR1 genotypes and the asthma phenotypes. Conclusion : LTC4S A(-444)C and CysLTR1 T(＋927)C polymorphisms and their gene-gene interactions are not associated with asthma phenotype, lung function, or BHR in Korean children. 목 적 : 류코트리엔은 천식의 병태생리에 중요한 향염증성 매개체이며, 천식이나 운동유발성 천식에서 증가되어 있다. Leukotriene C4 synthase (LTC4S)의 A(-444)C 유전자 다형성과 cysteinyl leukotriene receptor 1 (CysLTR1) T(＋927)C 유전자 다형성이 한국 소아의 천식, 아토피 천식 및 운동유발성 천식과 연관이 있는지 알아보고, 폐기능, 기관지과민성, 총IgE 치에 영향을 미치는지 알아보고자 하였다. 방 법 : 총 856명의 천식 환자와 254명의 천식이 없는 정상아를 대상으로 하여 피부반응검사, 폐기능, 메타콜린 기관지 유발검사, 총 IgE 검사를 실시하였고, 천식 환자를 아토피 천식(699명), 운동유발성 천식(277명)으로 나누어 유전자 다형성과의 연관성을 조사하였다. LTC4S A9-444)C, CysLTR1 T(＋927)C 유전자형은 PCR-restriction fragment length polymorphism 방법으로 분석하였다. 결 과 : LTC4S A(-444)C 및 CysLTR1 T(＋927)C 유전자 다형성은 천식, 아토피 천식, 운동유발성 천식과의 연관성이 없었고, 폐기능, $PC_{20}$, 총IgE에도 차이를 보이지 않았다. 아토피 천식에서 총 호산구수는 변종형 LTC4S 유전자형에서 야생형 보다 높았다. LTC4S A(-444)C와 CysLTR1 T(＋927)C의 유전자-유전자 상호 작용도 천식, 아토피