Correlation Between Serum CC16,TGF-β1 Levels And Pulmonary Function In Patients With COPD And Its Diagnostic Value

BackgroundChronic obstructive pulmonary disease（COPD）is characterized by persistent airflow limitation.Small airway inflammation is the pathological basis of COPD.Airway remodeling is the main reason for the development of the disease.Clara cell secretory protein（CC16）is a protein secreted by distal bronchial epithelial cells.It protects the lung by inhibiting the release of inflammatory mediators and reducing fibroblast production.Reduction of CC16 may cause aggravation of the inflammation in lung.Transforming growth factor-β1（TGF-β1）is a multifunctional growth factor related with cell proliferation and differentiation.TGF-β1 is recognized to be associated with respiratory diseases,and is involved in airway inflammation and airway structural remodeling.Studies have shown that the abnormal expression of CC16 and TGF-β1 in COPD patients may be related to irreversible airflow limitation of the airway.There have been studies on the correlation between serum CC16,TGF-β1 and pulmonary function at home and abroad,but the correlation are different.Research on the diagnostic value of serum CC16 and TGF-β1 in COPD is rare.It is necessary to further study the correlation between serum CC16,TGF-β1 and pulmonary function in COPD patients and its clinical diagnostic value.ObjectiveTo study the correlation between serum CC16,TGF-β1 and lung function in patients with COPD and its diagnostic value.To explore whether serum CC16,TGF-β1 can be used as a new biomarker to assess the severity of airflow restriction and to diagnose COPD.MethodsParticipants were selected from May 2018 to July 2019.100 patients with COPD（COPD group）and 50 healthy subjects（control group）were treated in the Department of Respiratory Medicine of the First Affiliated Hospital of Xinxiang Medical University.Pulmonary function meter was used to measure ratio of forced expiratory volume in one second to forced vital capacity（FEV₁/FVC）,and one second forced expiratory volume as a percentage of the expected value（FEV₁%pred）.Enzyme-linked immunosorbent assay（ELISA）was used to detect the serum CC16 and TGF-β1 levels of the subjects.Spearman correlation analysis was used to analyze the correlation between serum CC16,TGF-β1 and pulmonary function in patients with COPD.ROC curve was used to analyze the diagnostic value of serum CC16 and TGF-β1 in COPD.Results1.Compared with control group,the serum CC16 level in COPD group was significantly reduced（P<0.05）.The serum TGF-β1 level was significantly increased（P<0.05）.2.Spearman correlation analysis showed that the serum CC16 level in COPD group was positively correlated with FEV₁%pred and FEV₁/FVC%（r=0.819,r=0.684,P<0.01）.The serum TGF-β1 level in COPD group was negatively correlated with FEV1%pred and FEV1/FVC%（r=-0.821,r=-0.761,P<0.01）.3.The area under the curve of serum CC16 when diagnosing COPD is 0.866（P<0.05）,with the sensitivity 72%,the specificity 98%,the Youdon index 0.72,the best diagnostic threshold 98.13ng/mL.The area under the curve of serum TGF-β1 was 0.858（P<0.05）,with the sensitivity 74%,the specificity 96%,the Youdon index 0.70,he best diagnostic threshold was 688.2ng/L.Conclusion1.Serum CC16 is positively correlated with lung function in COPD patients,and serum TGF-β1 is negatively correlated with lung function in COPD patients.Serum CC16 and TGF-β1 levels showed diagnostic value in COPD.2.Serum CC16 and TGF-β1 are expected to become new biomarkers to evaluate the severity of airflow restriction in COPD patients and assist clinical diagnosis of COPD.