Lemanske Robert F
Departments of Pediatrics and Medicine, Division of Pediatric Allergy, Immunology, and Rheumatology, University of Wisconsin Medical School, 600 Highland Avenue, Madison, WI 53792, USA.
J Allergy Clin Immunol. 2004 Nov;114(5):1023-6. doi: 10.1016/j.jaci.2004.08.031.
Respiratory tract infections caused by viruses have been implicated in the pathogenesis of asthma. Of these respiratory pathogens, viruses have been demonstrated to be associated with asthma epidemiologically in at least 3 ways ( Fig 1 ). First, during infancy, certain viruses have been implicated in the inception of the asthmatic phenotype. Genetic susceptibility, particularly genes coding for atopic phenotypic characteristics, might differentiate, at least in part, those children who are destined to have persistent wheezing, asthma, or both later in childhood. Second, repeated exposure to infectious viruses in daycare centers or in households with multiple older siblings increases the number of respiratory infections, but in doing so, it might paradoxically reduce the long-term risk of allergies and asthma through either pre-existing or newly formed alterations in cytokine response profiles. Third, in patients with established asthma, particularly children, viral upper respiratory tract infections play a significant role in producing acute exacerbations of airway obstruction that might result in frequent outpatient visits or in hospitalizations. This review will highlight available data on respiratory syncytial virus infections and their relationship to asthma inception in childhood.
病毒引起的呼吸道感染被认为与哮喘的发病机制有关。在这些呼吸道病原体中，病毒已被证明在流行病学上与哮喘至少有3种关联方式（图1）。首先，在婴儿期，某些病毒与哮喘表型的起始有关。遗传易感性，特别是编码特应性表型特征的基因，可能至少部分地区分出那些在儿童后期注定会持续喘息、患哮喘或两者皆有的儿童。其次，在日托中心或有多个年长兄弟姐妹的家庭中反复接触传染性病毒会增加呼吸道感染的次数，但这样做可能会通过细胞因子反应谱中预先存在的或新形成的改变，反常地降低过敏和哮喘的长期风险。第三，在已确诊哮喘的患者中，特别是儿童，病毒性上呼吸道感染在导致气道阻塞急性加重方面起重要作用，这可能导致频繁的门诊就诊或住院。本综述将重点介绍关于呼吸道合胞病毒感染及其与儿童期哮喘起始关系的现有数据。
