Reduced Serum Concentration of CC16 Is Associated with Severity of Chronic Obstructive Pulmonary Disease and Contributes to the Diagnosis and Assessment of the Disease

BACKGROUND: The aim of this study was to reveal the correlations between serum concentration of Clara cell secretory protein (CC16) and clinical parameters of stable chronic obstructive pulmonary disease (COPD). PATIENTS AND METHODS: Serum concentration of CC16 was determined by enzyme-linked immunosorbent assay (ELISA). The correlations between serum concentration of CC16 and clinical parameters was performed by linear correlation analysis and multiple linear regression analysis. The sensitivity and specificity of serum CC16 for differential diagnosis of COPD were determined by receiver operator characteristic curve (ROC). RESULTS: The serum concentration of CC16 was down-regulated in stable COPD patients compared with healthy control group (p < 0.05). The decreased serum CC16 was negatively related to smoking (p < 0.05), GOLD grading (p < 0.005), mMRC score (p < 0.05) and medical history (p < 0.05) of patients, but positively correlated with pulmonary function (p < 0.05). The smoking, FEV1/FVC values, COPD grading and mMRC scores all affected the concentration of CC16 (p < 0.05). The decreased CC16 was an independent risk factor in the process of deterioration of lung function. The sensitivity and specificity of serum CC16 for identifying COPD reached to 65.3% and 75%. CONCLUSION: Decreased serum concentration of CC16 correlated with the disease progression of COPD, suggesting that it can be used as an indicator contributing to the diagnosis and assessment of COPD.