Role and clinical significance of CCR7 in asthmaic patients with cigarette smoke exposure

Objective To study the effect of cigarette smoke exposure on the expression of CC chemokine receptor 7 (CCR7) and its ligands of peripheral blood mononuclear cells in asthmatic patients, and to explore correlation between CCR7 and clinical targets. Methods The outpatients with asthma (asthma group, n=15) and smoking outpatients with asthma (smoking & asthma group, n=15) were enrolled in the study.Meanwhile, healthy controls (control group, n=15) and healthy smokers (smoking group, n=15)were matched.All of them required to blood test and assess asthma control test (ACT) score, blood gas analysis and lung function.CCR7 of peripheral blood mononuclear cells were measured by flow cytometry, CC chemokine ligand 21 (CCL21) and CCL19 in peripheral blood were measured by enzyme-linked immunosorbent assay. Results ①Compared with the control group, the expression of CCR7 protein increased remarkably in the asthma group and the smoking exposure combined asthma group (all P<0.01). Compared with the asthma group, the expression of CCR7 protein increased remarkably in the smoking combined asthma group (all P<0.01). ②Compared with the control group, CCL21 and CCL19 increased remarkably in the smoking combined asthma group (all P<0.01). Compared with the asthma group, CCL21 and CCL19 increased remarkably in the smoking combined asthma group (all P<0.01). ③Compared with the control group, forced expiratory volume in 1 second (FEV1) and peak expiratory flow (PEF) reduced remarkably in the asthma group and the smoking combined asthma group (all P<0.01). Compared with the asthma group, ACT score, FEV1 and PEF increased remarkably in the smoking combined asthma group (all P<0.01). ④The expression of CCR7 protein was negatively correlated with FEV1 and PEF (all P<0.01). Conclusions Smoking can increase the expression of CCR7 and its ligand CCL19 and CCL21, which may be result in the aggravation of symptoms and the decline of lung function in patient with asthma. Key words: CC chemokine receptor 7; Bronchial asthma; Chemokines; Lung function