目的 探讨吸烟的慢性阻塞性肺病（chronic obstructive pulmonary disease，COPD）患者外周血Bak基因表达异常及其与COPD发病的关系。方法 入选者包括健康对照组（不吸烟者10例、吸烟者14例）和轻中度吸烟COPD患者9例。使用Percoll非连续密度梯度沉降法分离人外周血中性粒细胞，使用real-time PCR来检测外周血中性粒细胞中Bak mRNA的表达水平。结果 相对于健康对照组，轻中度COPD患者外周血中性粒细胞中的Bak mRNA水平（0.88±0.38）明显降低，差异有统计学意义（P<0.05）；吸烟健康者外周血中性粒细胞中Bak mRNA水平（1.23±0.29）低于不吸烟健康者（1.33±0.38），但差异无统计学意义；Bak mRNA水平与FEV1/预计值%、FEV1/FVC%均呈正相关，相关系数r分别为0.438 8（P<0.05）和0.432 1（P<0.05）。结论 Bak基因表达异常可能与COPD发病有一定关系。Bak mRNA水平与临床肺功能之间有明显相关性，推测可能与COPD的严重程度相关。

Objective To investigate the relationship between abnomal expression of Bak gene in peripheral blood in chronic obstructive pulmonary disease (COPD) smokers and the pathogenesis of COPD. Methods We included 10 healthy non-smokers, 14 healthy smokers and 9 mild to moderate COPD smokers. Human peripheral blood neutrophils were isolated by using Percoll discontinuous density gradient sedimentation. And we detected mRNA levels of Bak gene in peripheral blood neutrophils by using Real-time PCR. Results Levels of Bak mRNA in circulating neutrophils of mild to moderate COPD smokers decreased statistically compared to healthy subjects (P<0.05). Levels of Bak mRNA in healthy smokers were lower than in that of healthy non-smokers without significant difference (P>0.05). Bak mRNA levels and FEV1/FEV1 pred% were positively correlated, as well as Bak mRNA levels and FEV1/FVC%. Conclusions There is possible relationship between abnormal expression of Bak gene and pathogenesis of COPD. In addition, levels of Bak mRNA might be related to the severity of COPD.