Mai Xiao-Mei, Nilsson Lennart, Kjellman N-I Max, Björkstén Bengt
Department of Health and Environment, Division of Paediatrics, Faculty of Health Sciences, Linköping University, Sweden.
Pediatr Allergy Immunol. 2002 Oct;13(5):361-7. doi: 10.1034/j.1399-3038.2002.01011.x.
The hypertonic saline challenge test is the recommended method to assess bronchial hyperresponsiveness in the International Study of Asthma and Allergies in Childhood (ISAAC). The sensitivity of this procedure to assess asthma symptoms, however, has been reported to vary among study centers. The purpose of our study was to evaluate the value of this provocation test in an epidemiological survey in children, and to relate the degree of bronchial hyperresponsiveness to the severity of asthma symptoms. All 11-13-year-old children from 16 randomly selected schools in Linköping, Sweden received a questionnaire regarding respiratory symptoms and allergic disease. Skin prick tests with eight inhalant allergens were performed. In addition, all children with wheeze over the past 12 months (current wheeze) and a random sample of children without current wheeze were invited to perform hypertonic saline provocation tests. A complete data set was available for 170 children, including 50 with and 120 without current wheeze. Bronchial hyperresponsiveness (BHR) was defined as at least 15% decline in FEV1. The degree of BHR was represented by the response/dose ratio, i.e. the fall in FEV1 divided by total dose of inhaled saline. The severity of asthma symptoms was classified by the number of wheezing episodes over the past 12 months. 'Asthma ever' was defined by a combination of symptoms in the questionnaires. Children with 'asthma ever' and current wheeze were considered as having current asthma. Current atopic asthma was defined as current asthma with at least one positive skin prick test. The sensitivity of the procedure to detect 'asthma ever', current asthma and current atopic asthma was 62, 61 and 83%, and the specificity 83, 81 and 60%, respectively. The positive challenge rate was 52, 34, 13 and 7% among current wheezers, previous wheezers, non-wheezers with a history of allergy and healthy children. The degree of bronchial hyperresponsiveness increased with the number of wheezing episodes. Thus, the median and range of the response/dose ratio were 4.8%/ml (2.1-14.8), 2.6%/ml (0.7-8.6) and 1.3%/ml (0.8-2.7), respectively, for children with >/= 4 episodes, 1-3 episodes and no wheezing episodes over the past 12 months (p<0.001). In conclusion, hypertonic saline provocation test is useful as a tool to detect asthma in epidemiological studies in children. The degree of bronchial hyperresponsiveness, as represented by the response/dose ratio, reflects the severity of asthma symptoms.
高渗盐水激发试验是《儿童哮喘与过敏国际研究》（ISAAC）中推荐的评估支气管高反应性的方法。然而，据报道，该方法评估哮喘症状的敏感性在各研究中心之间存在差异。我们研究的目的是评估这种激发试验在儿童流行病学调查中的价值，并将支气管高反应性程度与哮喘症状的严重程度相关联。瑞典林雪平16所随机选取学校中所有11 - 13岁的儿童都收到了一份关于呼吸道症状和过敏性疾病的问卷。对8种吸入性变应原进行了皮肤点刺试验。此外，所有在过去12个月内有喘息（当前喘息）的儿童以及无当前喘息的儿童随机样本被邀请进行高渗盐水激发试验。170名儿童有完整的数据集，包括50名有当前喘息和120名无当前喘息的儿童。支气管高反应性（BHR）定义为FEV1至少下降15%。BHR的程度由反应/剂量比表示，即FEV1的下降值除以吸入盐水的总剂量。哮喘症状的严重程度根据过去12个月内喘息发作的次数进行分类。“曾经患哮喘”由问卷中的症状组合定义。有“曾经患哮喘”且当前喘息的儿童被视为患有当前哮喘。当前特应性哮喘定义为当前哮喘且至少有一次皮肤点刺试验呈阳性。该方法检测“曾经患哮喘”、当前哮喘和当前特应性哮喘的敏感性分别为62%、61%和83%，特异性分别为83%、81%和60%。当前喘息者、既往喘息者、有过敏史的非喘息者和健康儿童的阳性激发率分别为52%、34%、13%和7%。支气管高反应性程度随喘息发作次数增加。因此，对于在过去12个月内喘息发作次数≥4次、1 - 3次和无喘息发作的儿童，反应/剂量比的中位数及范围分别为4.8%/ml（2.1 - 14.8）、2.6%/ml（0.7 - 8.6）和1.3%/ml（0.8 - 2.7）（p<0.001）。总之，高渗盐水激发试验在儿童流行病学研究中作为检测哮喘的工具是有用的。以反应/剂量比表示的支气管高反应性程度反映了哮喘症状的严重程度。
