Abstract: Objective To explore the correlation between the serum level of thymus and activation-regulated chemokine/CC chemokine ligand 17(CCL17) and the rapid decline of forced expiratory volume in one second (FEV1) in the elderly patients with chronic obstructive pulmonary disease (COPD). Methods A total of 203 patients with stable COPD treated in our hospital from August 2018 to December 2019 were enrolled in this study, and the patients were divided into rapid decline group and control group according to FEV1 variation within 1 year of follow up. The basic data of two groups were compared,and the relationship between CCL17 and FEV1 variation within 1 year of follow up(ΔFEV1) was analyzed. Multivariate Logistic regression was performed to analyze the related factors of rapid decline of lung function. Results The frequency of acute exacerbation,the serum levels of amyloid A (SAA),CCL17 and fasting plasma glucose (FPG) in the rapid decline group were higher than those in the control group,and the level of body mass index (BMI) in the rapid decline group was lower than that in the control group(all P<0.05). CCL17 was positively correlated with ΔFEV1 (r=0.525,P<0.001). Multivariate Logistic regression showed that SAA,CCL17 and smoking were the independent risk factors of rapid decline in lung function, and BMI was the independent protective factor. The cut-off value of CCL17 to predict rapid decline of lung function in the elderly COPD patients was 364.04 pg/mL,with an AUC of 0.876,with a sensitivity of 80.00%. Conclusions Serum CCL17 level is related to lung function variation in the elderly patients with COPD,and detecting serum CCL17 may bring benefits to predict the patients’ prognosis.

Key words: chronic obstructive pulmonary disease, thymus and activation-regulated chemokine/CC chemokine ligand 17, lung function, forced expiratory volume in one second