Rogers A V, Adelroth E, Hattotuwa K, Dewar A, Jeffery P K
Lung Pathology Unit, Department of Gene Therapy, Imperial College London, London, UK.
Thorax. 2008 Feb;63(2):108-14. doi: 10.1136/thx.2007.078253. Epub 2007 Sep 17.
Bronchial mucosal dendritic cells (DCs) initiate and regulate immune responses to inhaled antigens, viruses and bacteria. Currently, little is known of their numbers in patients with chronic obstructive pulmonary disease (COPD). While reductions in their numbers have been reported recently in smokers with asthma, nothing is known of the effects of cigarette smoking on bronchial DCs in COPD. The present study compares DC numbers in smokers and ex-smokers with COPD.
Endobronchial biopsies were obtained from 15 patients with moderate to severe COPD (10 current smokers with median forced expiratory volume in 1 s (FEV1) 45.5% predicted (range 23-68) and 5 ex-smokers with median FEV1 30% predicted (range 21-52)), 11 non-smokers with asthma (median FEV1 102% predicted (range 89-116)) and 11 non-smoker healthy controls (median FEV1 110% predicted (range 92-135)). Transmission electron microscopy (TEM) was used to identify the total population of DCs by their ultrastructure and their number in the epithelium and subepithelium was counted.
Median (range) DC numbers were significantly lower in current smokers with COPD in the epithelium (0.0 (0.0-156.8) cells/mm2) and the subepithelium (4.5 (0.0-63.6) cells/mm2) compared with ex-smokers with COPD (97.9 (93.5-170.3) cells/mm2 in the epithelium (p<0.05); 91.8 (38.2-283.3) cells/mm2 in the subepithelium (p<0.01)). DC numbers in ex-smokers with COPD were similar to those in subjects with atopic asthma and healthy controls (131.6 (33.3-235.5) cells/mm2 in the epithelium and 64.4 (0.0-182.4) cells/mm2 in the subepithelium for the latter).
In COPD, bronchial mucosal DC numbers are lower in current smokers while, in those who quit, numbers are similar to non-smoking subjects with asthma and non-smoking healthy controls. The functional consequences of the reduction in mucosal DC numbers in smokers with COPD have yet to be determined.
支气管黏膜树突状细胞（DCs）启动并调节对吸入抗原、病毒和细菌的免疫反应。目前，对于慢性阻塞性肺疾病（COPD）患者体内这些细胞的数量了解甚少。虽然最近有报道称哮喘吸烟者体内的DC数量减少，但对于吸烟对COPD患者支气管DC的影响尚不清楚。本研究比较了COPD吸烟者和戒烟者的DC数量。
对15例中重度COPD患者（10例现吸烟者，1秒用力呼气容积（FEV1）中位数为预测值的45.5%（范围23%-68%）；5例戒烟者，FEV1中位数为预测值的30%（范围21%-52%））、11例非吸烟哮喘患者（FEV1中位数为预测值的102%（范围89%-116%））和11例非吸烟健康对照者（FEV1中位数为预测值的110%（范围92%-135%））进行支气管活检。采用透射电子显微镜（TEM）通过超微结构识别DC的总数，并对上皮和上皮下的DC数量进行计数。
与COPD戒烟者相比，COPD现吸烟者上皮（0.0（0.0-156.8）个细胞/mm²）和上皮下（4.5（0.0-63.6）个细胞/mm²）的DC数量中位数（范围）显著降低（上皮中分别为97.9（93.5-170.3）个细胞/mm²（p<0.05）；上皮下为91.8（38.2-283.3）个细胞/mm²（p<0.01））。COPD戒烟者的DC数量与特应性哮喘患者和健康对照者相似（后者上皮中为131.6（33.3-235.5）个细胞/mm²，上皮下为64.4（0.0-182.4）个细胞/mm²）。
在COPD患者中，现吸烟者的支气管黏膜DC数量较低，而戒烟者的DC数量与非吸烟哮喘患者和非吸烟健康对照者相似。COPD吸烟者黏膜DC数量减少的功能后果尚待确定。
