Abstract: Objective To explore the expression level of serum chemokine ligand 18（CCL-18） in patients with acute exacerbation of chronic obstructive pulmonary disease(AECOPD) and its diagnostic value.Methods A total of 60 patients with AECOPD(AECOPD group) were concluded.According to the frequency of acute exacerbation of COPD in the past year,they were divided into frequent group(27 cases) and accidental group(33 cases).According to the stage of global initiative for COPD(GOLD),they were divided into stage Ⅰ+Ⅱ group(30 cases),stage Ⅲ group(20 cases) and stage Ⅳ group(10 cases).The 20 healthy smokers with normal lung function were selected as the control group.Levels of serum CCL-18 in subjects of each group were detected by enzyme linked immunosorbent assay(ELISA) and compared.The diagnostic efficacy of serum CCL-18 in distinguishing AECOPD patients from healthy controls,frequent AECOPD patients from occasional AECOPD patients was analyzed by receiver operating characteristic(ROC) curve.Results Level of serum CCL-18 in patiens of AECOPD group was higher than that in control group(P<0.001).Level of serum CCL-18 in AECOPD patietns of frequent group was higher than that in incidental group(P<0.05).Levels of serum CCL-18 in stage Ⅰ+Ⅱ group,stage Ⅲ group and stage Ⅳ group increased gradually,and the differences were significant(P<0.05).Results of ROC curve analysis showed that sensitivity,specificity and area under ROCcurve(AUC) of serum CCL-18 in diagnosing AECOPD were 84.1%,76.7% and 0.86(95% CI 0.77~0.94,P<0.001) respectively.Sensitivity,specificity and AUC of serum CCL-18 in diagnosing frequent AECOPD were 88.0%,88.2% and 0.92(95%CI 0.85~0.99,P<0.001).Conclusion The level of serum CCL-18 in patients with AECOPD is higher than that in healthy controls,and it increases along with GOLD stage increasing.Serum CCL-18 can distinguish AECOPD patients from healthy controls,frequent AECOPD patients and incidental AECOPD patients.

Key words: Chronic obstructive pulmonary disease, Acute exacerbation, Serum chemokine ligand 18, Diagnostic value