Department of Medicine, Division of Pulmonary and Critical Care, University of Washington, Seattle, Washington 98195, USA.
Curr Opin Allergy Clin Immunol. 2012 Feb;12(1):42-8. doi: 10.1097/ACI.0b013e32834ecc67.
Exercise-induced bronchoconstriction (EIB) refers to acute airflow obstruction that is triggered by a period of physical exertion. Here we review recent findings about the epidemiology of EIB, immunopathology leading to EIB, and the latest understanding of the pathogenesis of EIB.
Longitudinal studies demonstrated that airway hyper-responsiveness to exercise or cold air at an early age are among the strongest predictors of persistent asthma. Patients that are susceptible to EIB have epithelial disruption and increased levels of inflammatory eicosanoids such as cysteinyl leukotrienes (CysLT)s. The leukocytes implicated in production of eicosanoids in the airways include both a unique mast cell population as well as eosinophils. A secreted phospholipase A(2) (sPLA(2)) enzyme that serves as a regulator of CysLT formation is present in increased quantities in asthma. Transglutaminase 2 (TGM2) is expressed at increased levels in asthma and serves as a regulator of secreted phospholipase A(2) group X (sPLA(2)-X). Further, sPLA(2)-X acts on target cells such as eosinophils to initiate cellular eicosanoid synthesis.
Recent studies have advanced our understanding of EIB as a syndrome that is caused by the increased production of inflammatory eicosanoids. The airway epithelium may be an important regulator of the production of inflammatory eicosanoids by leukocytes.
运动诱发性支气管收缩（EIB）是指由体力活动引发的急性气流阻塞。本文回顾了 EIB 的流行病学、导致 EIB 的免疫病理学以及 EIB 发病机制的最新理解。
纵向研究表明，年轻时对运动或冷空气的气道高反应性是持续性哮喘的最强预测因素之一。易发生 EIB 的患者存在上皮细胞破坏和炎症类二十烷酸（CysLT）等水平升高。参与气道中类二十烷酸生成的白细胞包括独特的肥大细胞群和嗜酸性粒细胞。一种作为 CysLT 形成调节剂的分泌型 PLA2（sPLA2）酶在哮喘中大量存在。转谷氨酰胺酶 2（TGM2）在哮喘中表达水平增加，作为分泌型 PLA2 组 X（sPLA2-X）的调节剂。此外，sPLA2-X 作用于嗜酸性粒细胞等靶细胞，启动细胞内类二十烷酸的合成。
最近的研究提高了我们对 EIB 作为一种由炎症类二十烷酸产生增加引起的综合征的认识。气道上皮细胞可能是白细胞产生炎症类二十烷酸的重要调节者。
