Objective To investigate the effects of tobacco smoke exposure on histone deacetylase 2 (HDAC2),interleukin-8(IL-8)and tumor necrosis factor-α(TNF-α)expression in peripheral blood of patients with lung adenocarcinoma and analyze the relationships among them. Methods Seventy-three cases diagnosed as lung adenocarcinoma were collected in the First Affiliated Hospital and Affiliated Tumor Hospital of Guangxi Medical University from April 2014 to March 2015.All patients underwent lung function test preoperatively.Fourteen healthy volunteers without tobacco smoke exposure and chronic obstructive pulmonary disease (COPD)were recruited as healthy control.According to the lung function and tobacco smoke exposure,all cases were divided into four groups,ie. a healthy control group (group A,14 cases),a group without tobacco smoke exposure and COPD(group B,19 cases),a group with tobacco smoke exposure and without COPD(group C,33 cases),and a group with tobacco smoke exposure and COPD(group D,21 cases).The expressions of HDAC2 mRNA,IL-8 mRNA and TNF-α mRNA in peripheral blood mononuclear cells (PBMCs)were detected by real-time polymerase chain reaction (PCR).The contents of IL-8 and TNF-α in serum were detected by ELISA. Results Compared with group A,the HDAC2 mRNA expression in PBMCs had no difference in group B(P>0.05),and was down-regulated significantly in group C and D (P<0.05),which in group D was the most obvious.Compared with group A,the expressions of IL-8 mRNA and TNF-α mRNA in PBMCs and the contents of IL-8 and TNF-α in serum were significantly higher in all lung adenocarcinoma patients(all P<0.05),and the up-regulation was more obvious in group D.The relative expression of HDAC2 mRNA in PBMCs showed no significant difference with respect to age,gender or TNM stage (P>0.05).IL-8 and TNF-α in PBMCs and serum showed no significant difference with respect to age and gender (P>0.05),and were higher in the patients with TNM stage Ⅲ lung adenocarcinoma than those with stage Ⅰ and Ⅱ(P<0.05),with no obvious difference between stage Ⅰ and stage Ⅱ (P>0.05). Conclusion Tobacco smoke exposure causes lower expression of HDAC2 and over-expression of IL-8 and TNF-α in peripheral blood of patients with lung adenocarcinoma,can aggravate inflammatory response especially when complicated with COPD,which may be related to the prognosis of lung adenocarcinoma.