Yu T R, Kuo H P
Department of Internal Medicine, Chang Gung Memorial Hospital, Taipei, Taiwan, R.O.C.
J Formos Med Assoc. 1993 May;92(5):407-12.
Eosinophils are the most prominent inflammatory cells involved in the development of bronchial hyperresponsiveness in bronchial asthma. There is evidence that eosinophils in the peripheral blood are a heterogeneous cell population. The heterogeneity of eosinophils in the peripheral blood from 16 patients with mild to moderate bronchial asthma and seven normal subjects was studied using Percoll density fractionation. Eosinophils recovered from patients with bronchial asthma were mainly in the lower density fractions (< 1.095 g/mL), whereas eosinophils from normal subjects were in the higher density fractions (> 1.095 g/mL). The total cell count and the proportion of hypodense eosinophils were highly correlated with the provoking concentration (PC20) of methacholine, which caused a 20% decrease in FEV1 but not in the baseline spirometry. Disease severity, determined on the grounds of clinical history and the peak expiratory flow rate as well as its variability, showed that patients with moderate bronchial asthma had a higher count of hypodense eosinophils than those with mild bronchial asthma. This study shows that eosinophils from asthmatics, when compared with those from control subjects, are heterogeneous and predominantly hypodense cells. Changes in the repartition of the eosinophil subpopulations may be of critical importance in determining the magnitude of the inflammatory response of the airways in bronchial asthma.
嗜酸性粒细胞是参与支气管哮喘中支气管高反应性发展的最主要炎症细胞。有证据表明外周血中的嗜酸性粒细胞是一个异质性细胞群体。使用Percoll密度梯度离心法研究了16例轻至中度支气管哮喘患者和7名正常受试者外周血中嗜酸性粒细胞的异质性。从支气管哮喘患者中回收的嗜酸性粒细胞主要存在于较低密度组分（<1.095 g/mL）中，而正常受试者的嗜酸性粒细胞则存在于较高密度组分（>1.095 g/mL）中。细胞总数和低密度嗜酸性粒细胞的比例与乙酰甲胆碱激发浓度（PC20）高度相关，PC20可使第一秒用力呼气容积（FEV1）降低20%，但对基础肺量计检查无影响。根据临床病史、呼气峰值流速及其变异性确定的疾病严重程度表明，中度支气管哮喘患者的低密度嗜酸性粒细胞计数高于轻度支气管哮喘患者。这项研究表明，与对照组相比，哮喘患者的嗜酸性粒细胞是异质性的，且主要是低密度细胞。嗜酸性粒细胞亚群分布的变化可能对确定支气管哮喘气道炎症反应的程度至关重要。
