Study subject
A total of 393 bronchial asthmatic children aged between 5 and 12 years, consisting of 318 stable asthmatics and 75 acute asthma attack sufferers (47 males and 28 females), were recruited from the pediatric clinics of the Chang Gung Memorial Hospital, Taiwan, as a part of the ongoing PATCH study (Prediction of Allergies in Taiwanese Children). A total of 97 (59 males and 38 females) age-matched healthy subjects were enrolled from an elementary school in Taoyuan City, Taiwan. The diagnosis and classification of the clinical severity of asthma followed the published guidelines12. Asthma severity was categorized as mild (intermittent), moderate and severe, based on the previously described criteria11. An acute asthma attack was defined as a patient with dyspnea symptoms and audible expiratory wheeze accompanied by a 20% reduction in FEV1. Levels of EBC eicosanoids, FEV1, and FeNO were measured during acute asthma attack episodes and at two weeks after the acute asthma attacks. For the management of acute asthma exacerbation, all of the asthmatic children received terbutaline inhalation and oral prednisolone 1 mg/kg/day for 3 days. In the two weeks prior to EBC collection, none of the patients took medication containing antipyretics or anti-platelet agents. The healthy, non-asthmatic, and non-allergic subjects served as normal controls. This study was approved by the Humane Research Committee of the Chang Gung Memorial Hospital and informed consents were obtained from patients’ parents or guardians prior to the start of the study. Additional phenotypes included BMI, serum IgE levels, FEV1, and FeNO measured as previously described13.