Correlation Between FeNo And Eosinophilv?ESR?CRP?Pulmonary Function In Patients With Asthma-COPD Overlap

Background and PurposeBronchial Asthma(BA)and Chronic obstructive pulmonary disease(COPD)are two types of chronic respiratory diseases with different clinical features and pathogenesis.They are chronic airway inflammatory diseases characterized by airflow limitation.However,the clinical symptoms and inflammatory reactions of the two diseases are similar.It is very difficult to identify the two diseases only by clinical symptoms.More complicated is the presence of COPD with asthma,known as asthma-COPD overlap(ACO).Asthma-chronic obstructive pulmonary overlap(ACO)is a combination of asthma and COPD.Patients are more susceptible to acute exacerbations caused by external and self-conditions,which seriously reduces the quality of life of patients and has a high mortality rate.Therefore,early identification of ACO from asthma and chronic obstructive pulmonary disease,giving priority to attention,is a problem that needs to be resolved as soon as possible in our clinical work.In recent years,as a marker of airway inflammation,Fractional exhaled nitric oxide(FeNO)has been widely used in respiratory diseases.FeNO is mainly derived from airway epithelial cells and is induced by nitric oxide synthase.Nitric oxide synthase is mainly secreted by various inflammatory cells,such as eosinophils,macrophages and so on.Therefore,the detection of FeNO can indirectly reflect the inflammation of the airway.Therefore,this study mainly focused on the application and value of FeNO in asthma-COPD overlap patients,and compared its correlation with eosinophils,erythrocyte sedimentation rate,CRP and lung function.Methods:The study was conducted in the Department of Respiratory Medicine,Pingxiang People's Hospital.From May 2016 to May 2018,68 patients with ACO(ACO group),64 patients with asthma(asthma group),80 patients with chronic obstructive pulmonary disease(COPD group)and 80 patients with health check-up(control group)were selected for research purposes.FeNO,eosinophil,erythrocyte sedimentation rate,CRP and pulmonary function were measured in all the four groups.We analyze The levels of FeNO,eosinophils,erythrocyte sedimentation rate,CRP and pulmonary function in each group,and analyze the correlation and clinical significance of each index.Statistical analysis:Statistical analysis of test data was carried out by SPSS20.0 software.The measurement data are expressed as mean standard deviation(),and the results among groups are compared by variance analysis.X~2 test was used to analyze and compare the differences among the groups,and the percentage(%)was used to represent the counting data,Peason analysis was used to analyze the correlation between data.The difference was statistically significant with P<0.05?Results:1.FeNO?peripheral blood eosinophils and erythrocyte sedimentation rate(ESR)were measured and compared in 80 control group,80 COPD group,64 asthma group and 68 ACO group.the result as follows:The control group<COPD group<ACO group<asthma group(P<0.05),the difference was statistically significant.This suggests that the values of FeNO,blood eosinophils and erythrocyte sedimentation rate in ACO group are higher than those in COPD and healthy control group,but lower than those in asthma group.The CRP value of the four groups as follows:the control group<COPD group<asthma group<ACO group.The CRP value of the ACO group was higher than that of the other three groups.Contrastive analysis of FEV1%pred and FEV1/FVC%values in four groups.It is suggested that there is no significant change in pulmonary function in ACO group compared with COPD group,but the pulmonary function is worse in ACO group compared with asthma group(P<0.05).2.The diagnostic value of FeNO for ACO was analyzed by ROC curve,which indicated that FeNO had high sensitivity and specificity for the diagnosis of ACO.The optimum threshold is 28.7 x 10~9,The area under ROC line is 0.828,95%CI is0.79-0.90.3.Pearson correlation analysis was used to analyze the correlation between FeNO and various detection indicators.FeNO is positively correlated with blood eosinophil ratio(The correlation coefficient r=0.734,P=0.013)and erythrocyte sedimentation rate(The correlation coefficient r=0.578,P=0.038).There was no significant correlation between FeNO and FEV1%pred(correlation coefficient r=0.132,P=0.326),FEV1/FVC%value(correlation coefficient r=0.123,P=0.334),CRP(correlation coefficient r=0.168,P=0.109)?Conclusion:FeNO is positively correlated with blood eosinophil ratio and erythrocyte sedimentation rate.Combined detection of FeNO,blood eosinophil ratio,and erythrocyte sedimentation rate is helpful for early identification of ACO.FeNO can be used as an indicator to evaluate the level of inflammation in patients.