THE PRESENCE OF AIRWAY REACTIVITY BEFORE THE DEVELOPMENT OF ASTHMA
THE PRESENCE OF AIRWAY REACTIVITY BEFORE THE DEVELOPMENT OF ASTHMA
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DOI：
10.1164/ajrccm/141.1.2
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发表时间：
1990-01-01
期刊：
影响因子：
--
通讯作者：
NAIR, NM
中科院分区：
文献类型：
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作者：
HOPP, RJ;TOWNLEY, RG;NAIR, NM
过度的气道反应性是当前哮喘的一个重要组成部分。然而，尚不清楚气道反应性是由遗传决定还是后天获得的。为了检验哮喘发生前支气管反应性增加的可能性，我们报告了 20 名受试者，他们在临床哮喘发作之前和之后进行了研究。受试者是正在进行的一项更大规模的哮喘自然史研究的一部分。十三名受试者对国家心肺血液研究所呼吸问卷的回答表明，他们在初次就诊时没有哮喘。七名受试者在初次就诊时出现肺部症状，但并未被诊断为哮喘。使用标准化乙酰甲胆碱激发评估支气管反应性。对于这 20 名受试者，初次就诊和诊断出哮喘之间的平均间隔为 3.5 年。 13 名非哮喘受试者中有 10 名在哮喘发作前对醋甲胆碱有中度或强阳性反应（208 个呼吸单位或更少）。将这 13 名受试者与年龄和性别匹配的对照组（来自哮喘和非哮喘家庭，但未患哮喘）进行了比较。初次就诊时，13 名研究对象和来自非哮喘家庭的对照对象之间的支气管反应存在差异，但这些对象和来自哮喘家庭的对照对象之间没有差异。 7 名患有肺部症状的受试者中有 5 名的反应为 100 呼吸单位或更少。总体而言，在哮喘诊断确定后，20 名受试者中有 19 名对醋甲胆碱产生了强烈的阳性反应。结果表明，气道反应性增强通常先于哮喘的发生，这可能支持哮喘的遗传基础。
Exaggerated airway reactivity is an essential component of the current asthmatic. It is not clear, however, if airway reactivity is genetically determined or acquired. To examine the possibility that increased bronchial reactivity exists prior to the development of asthma, we report on 20 subjects who were studied before and after the onset of clinical asthma. Subjects were part of a larger on-going study of the Natural History of Asthma. Thirteen subjects indicated by their answers to the National Heart, Lung, and Blood Institute respiratory questionnaire that they were not asthmatic at their initial visit. Seven subjects had pulmonary symptoms on their initial visit, but had not been diagnosed as asthmatic. Bronchial reactivity was assessed using a standardized methacholine challenge. For the 20 subjects, there was a mean interval of 3.5 yr between the initial visit and the diagnosis of asthma. Ten of 13 nonasthmatic subjects had moderate or strongly positive responses (208 breath units or less) to methacholine prior to onset of asthma. These 13 subjects were compared to age- and sex-matched controls, from both asthmatic and nonasthmatic families, who had not become asthmatic. There was a difference in bronchial responses at the initial visit between the 13 study subjects and their control subjects from nonasthmatic families, but not between the subjects and their controls from asthmatic families. Five of 7 subjects with pulmonary symtoms had responses of 100 breath units or less. Overall, 19 of 20 subjects had strongly positive repsonses to methacholine after the diagnosis of asthma was established. The results show that enhanced airway reactivity usually precedes the development of asthma, which could support a genetic basis for it.