Kim Chang Keun, Kim Sang Woo, Park Choon Sik, Kim Beyong Il, Kang Hee, Koh Young Yull
Department of Pediatrics, Inje University Sanggye Paik Hospital, Seoul, Korea.
J Allergy Clin Immunol. 2003 Jul;112(1):64-71. doi: 10.1067/mai.2003.1618.
The pathogenetic basis for the relationship between acute bronchiolitis and asthma has not yet been completely elucidated.
The aim of this study was to compare these 2 diseases in terms of their patterns of airway cytokine response (T(H)1 or T(H)2).
By using a bronchoalveolar lavage (BAL) technique, this study investigated the cytokine levels of BAL fluid in children with acute asthma who had no identifiable respiratory syncytial virus (RSV) infection (n = 18) and in infants with acute bronchiolitis caused by RSV (n = 22). Comparisons were made with normal control subjects (n = 14). IFN-gamma (T(H)1) and IL-4 and IL-5 (T(H)2) levels were measured in concentrated BAL fluids by means of ELISA.
The IL-5 level (P <.001) and IL-5/IFN-gamma ratio (P <.001) were significantly increased in the asthmatic group with no identifiable RSV infection and in the RSV-induced bronchiolitis group compared with values in the control group. When infants in the bronchiolitis group were divided into eosinophil-positive and eosinophil-negative subgroups, the eosinophil-positive subgroup had significantly increased IL-5 levels (P <.001) and IL-5/IFN-gamma ratios (P <.01) compared with those in the control group, but similar cytokine responses were not induced in the eosinophil-negative subgroup. The percentage of BAL eosinophils correlated significantly with levels of BAL IL-5 in both the asthma group (r = 0.80, P =.000) and the bronchiolitis group (r = 0.82, P =.000).
These findings suggest that a subgroup of the RSV-induced bronchiolitis group results in a T(H)2-type response, and this could provide a valuable framework to explain the link between RSV-induced bronchiolitis and asthma.
急性细支气管炎与哮喘之间关系的发病机制尚未完全阐明。
本研究旨在比较这两种疾病在气道细胞因子反应模式（Th1或Th2）方面的差异。
本研究采用支气管肺泡灌洗（BAL）技术，调查了无明确呼吸道合胞病毒（RSV）感染的急性哮喘儿童（n = 18）和由RSV引起的急性细支气管炎婴儿（n = 22）支气管肺泡灌洗液中的细胞因子水平。并与正常对照组（n = 14）进行比较。通过ELISA法测定浓缩支气管肺泡灌洗液中IFN-γ（Th1）、IL-4和IL-5（Th2）水平。
与对照组相比，无明确RSV感染的哮喘组和RSV诱导的细支气管炎组的IL-5水平（P <.001）和IL-5/IFN-γ比值（P <.001）显著升高。当细支气管炎组的婴儿分为嗜酸性粒细胞阳性和嗜酸性粒细胞阴性亚组时，与对照组相比，嗜酸性粒细胞阳性亚组的IL-5水平（P <.001）和IL-5/IFN-γ比值（P <.01）显著升高，但嗜酸性粒细胞阴性亚组未诱导出类似的细胞因子反应。哮喘组（r = 0.80，P =.000）和细支气管炎组（r = 0.82，P =.000）支气管肺泡灌洗嗜酸性粒细胞百分比与支气管肺泡灌洗IL-5水平均显著相关。
这些发现表明，RSV诱导的细支气管炎组中的一个亚组会导致Th2型反应，这可能为解释RSV诱导的细支气管炎与哮喘之间的联系提供一个有价值的框架。
