Study subject
A total of 393 bronchial asthmatic children aged between 5 and 12 years, consisting of 318 stable asthmatics (205 males and 113 females) 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 with no history of bronchial asthma, allergic, or immunological diseases) 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. The mild-asthma group exhibited a symptom frequency of less than once a day and nocturnal symptoms of less than once a week, with an FEV1 > 80% of predict as well as those experiencing minor limitations in their daily activities. The inclusion criteria for the children with severe asthma consisted of frequent daytime symptoms and night waking maybe every night, an FEV1 <60% of predicted and experienced major limitations in their daily activities. Patients with moderate asthma had features between these two extremes. 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 that would have suppressed platelet function. The healthy, non-asthmatic, and non-allergic subjects served as normal controls. This study was approved by the Humane Research Committee and informed consents were obtained from patients’ parents or guardians prior to the start of the study. Additional phenotypic characterization for participants with asthma included assessment for BMI and measurement of serum IgE levels (UniCap 100, Pharmacia, Uppsala, Sweden), FEV1, and fraction of exhaled nitric oxide (FeNO) levels.