慢性咳嗽和喘息性疾病支气管肺泡灌洗液成分分析

Analysis of bronchoalveolar lavage fluid components in children with chronic cough and wheezy diseases

目的 分析慢性咳嗽及喘息性疾病患儿支气管肺泡灌洗液成分。方法 应用免疫组化及ELISA方法 ,对哮喘 (13例 )、慢性咳嗽 (10例 )、婴幼儿喘鸣 (8例 )患儿和对照组 (8例 )共 39例的支气管肺泡灌洗液进行细胞学分析及上清液IL 5浓度测定。结果 哮喘患儿支气管肺泡灌洗液嗜酸性粒细胞为 3 0 %(0 7%～ 8 8%) ,上皮细胞为 3 0 %(0 7%～ 12 0 %) ,IL 5为 1 6ng/L(0～ 16 0ng/L) ,与慢性咳嗽组及婴幼儿喘鸣组相比 ,差异有非常显著意义 (P <0 0 1) ;2例慢性咳嗽及 3例婴幼喘鸣儿嗜酸性粒细胞亦有异常增多 ,与组内其他患儿相比差异有显著意义 ;婴幼儿喘鸣组中性粒细胞明显增多。结论 哮喘患儿支气管肺泡灌洗液以嗜酸性粒细胞和上皮细胞明显增多为其特征性改变 ;慢性咳嗽患儿中有嗜酸性粒细胞异常增多者 ,应注意与哮喘鉴别 ;婴幼儿喘鸣者以中性粒细胞增多为著 ,抗哮喘治疗应慎重。

Objective Today the technique of bronchoalveolar lavage (BAL ) has been widely used as a useful research tool in studying the airway inflammation of airway diseases by investigating inflammatory cells and inflammatory mediators in bronchoalveolar lavage fluid (BALF ) in adults, but there have been very few the similar studies in pediatric cases. The purpose of this prospective study was to analyze the components of BALF in children with chronic cough and wheezy diseases. Methods Fiberoptic bronchoscopy was performed on 39 children aged 1 year to 11 years, who were divided into 4 groups with regard to clinical data: asthma (n=13), chronic cough (n=10), infantile wheezing (n= 8), and control (n= 8). BAL was performed with 3×1 ml/kg body weight of normal saline warmed to body temperature. Differential cell counts were obtained from smears stained with May-Grünwald-Giemsa method. Activated eosinophils and T cells were marked with EG2 and CD45RO monoclonal antibodies, respectively, using immunohistochemical method. Interleukin-5 (IL-5) was measured with a sandwich ELISA using a mouse monoclonal antibody. Statistical analysis was conducted with the SPSS 8.0 software. P< 0.05 was considered statistically significant.Results The mean (±s) recovery of BALF was (77±6)% and no difference was found between the groups. Eosinophils 3.0%(0.7%-8.8%), EG2-positive cells 2.0% (0.8%-7.5%), and epithelial cells 3.0% (0.7%-12.0%) in BALF were significantly increased in children with asthma by comparison with chronic cough, infantile wheezing and control subjects (P< 0.01, respectively). The cell profile of children with chronic cough was similar to that of control children, but increased eosinophils and EG2-positive cells were also found in two of them. Activated T cell (CD45RO +) counts were significantly increased in asthmatic children as compared with controls (P< 0.05 ) but no significant difference was found when compared with children with chronic cough and infantile wheezing. Neutrophils were significantly increased in asthmatic children and infantile wheezers in comparison with controls (P<0.05, respectively). IL-5 (1.6 ng/L; 0, 16.0 ng/ml) levels were significantly increased in asthmatic children as compared with controls and children with chronic cough(P< 0.05, respectively). CD45RO-positive cell counts, EG2-positive cell counts and IL-5 levels in BALF correlated positively with one another (r= 0.785 3, P<0.001; r= 0.918 7, P<0.001; r= 0.759 1, P<0.001, respectively). Conclusions Eosinophils and epithelial cells in BALF were significantly increased in children with asthma in comparison with chronic cough, infantile wheezing and control subjects; some children with chronic cough also had increased eosinophil counts; neutrophil was the main significantly increased cell in BALF in the children with infantile wheezing.