Koh Y I, Choi S
Department of Internal Medicine, Chonnam National University Medical School and Research Institute of Medical Science, Kwangju, Korea.
Respir Med. 2002 Feb;96(2):120-5. doi: 10.1053/rmed.2001.1238.
It has been suggested that airway eosinophilic inflammation is associated with the severity of exercise-induced bronchospasm (EIB). Blood eosinophils are known to be an indirect marker of airway inflammation in asthma. The aim of this study is to investigate that a simple and easy blood test for blood eosinphil counts may predict the severity of EIB in asthma. Seventy-seven men with perennial asthma (age range 18-23 years) were included. Lung function test, skin prick test, and blood tests for eosinophils counts and total IgE levels were performed. Methacholine bronchial provocation test and, 24 h later, free running test were carried out. EIB was defined as a 15% reduction or more in post-exercise FEV1 compared with pre-exercise FEV1 value. Atopy score was defined as a sum of mean wheal diameters to allergens. EIB was observed in 60 (78%) of 77 subjects. Asthmatics with EIB showed significantly increased percentages of eosinophils (P<0.01), log eosinophil counts (P<0.001), and atopy scores (P<0.05) and decreased log PC20 values (P < 0.05) compared with asthmatics without EIB. Asthmatics with eosinophils of > 700 microl(-1) (36.9 +/- 12.7%) had significantly greater maximal % fall in FEV1 after exercise than asthmatics with eosinophils of < 350 microl(-1) (24.7 +/- 16.6%, P <0.05). Blood eosinophil counts > 350 microl(-1) yielded the specificity of 88% and positive predictive value of 93% for the presence of EIB. When a multiple regression analysis of maximal % fall in FEV1 according to log eosinophil counts, log PC20, log IgE and atopy score was performed, only blood eosinophil counts were significant factor contributing to the maximal % fall in FEV1 after exercise. These findings not only suggest that a simple blood test for eosinophils may be useful in the prediction of the severity of EIB, but also reinforce the view that airway eosinophilic inflammation may play a major role in EIB in asthma.
有人提出气道嗜酸性粒细胞炎症与运动诱发性支气管痉挛（EIB）的严重程度相关。已知血液嗜酸性粒细胞是哮喘气道炎症的间接标志物。本研究的目的是调查一项简单易行的血液嗜酸性粒细胞计数检测是否可以预测哮喘患者EIB的严重程度。纳入了77名患有常年性哮喘的男性（年龄范围18 - 23岁）。进行了肺功能测试、皮肤点刺试验以及嗜酸性粒细胞计数和总IgE水平的血液检测。进行了乙酰甲胆碱支气管激发试验，24小时后进行自由跑步试验。EIB定义为运动后FEV1较运动前FEV1值降低15%或更多。特应性评分定义为对过敏原的平均风团直径之和。77名受试者中有60名（78%）出现了EIB。与无EIB的哮喘患者相比，患有EIB的哮喘患者的嗜酸性粒细胞百分比（P<0.01）、嗜酸性粒细胞计数对数（P<0.001）和特应性评分（P<0.05）显著增加，而PC20值对数降低（P<0.05）。嗜酸性粒细胞>700 μl⁻¹的哮喘患者（36.9±12.7%）运动后FEV1的最大下降百分比显著高于嗜酸性粒细胞<350 μl⁻¹的哮喘患者（24.7±16.6%，P<0.05）。血液嗜酸性粒细胞计数>350 μl⁻¹对EIB存在的特异性为88%，阳性预测值为93%。当根据嗜酸性粒细胞计数对数、PC20对数、IgE对数和特应性评分对FEV1的最大下降百分比进行多元回归分析时，只有血液嗜酸性粒细胞计数是运动后FEV1最大下降百分比的显著影响因素。这些发现不仅表明一项简单的嗜酸性粒细胞血液检测可能有助于预测EIB的严重程度，而且还强化了气道嗜酸性粒细胞炎症可能在哮喘患者的EIB中起主要作用的观点。
