The Expression And Significance Of IL-6,IL-8,FeNO And Eosinophils In Asthma-COPD Overlap

Objective:To investigate the expression and diagnostic value of four biomarkers including interleukin-6(IL-6),interleukin-8(IL-8),fractional exhaled nitric oxide(FeNO)and eosinophils(Eos)in asthma,chronic obstructive pulmonary disease(COPD),and asthma-COPD overlap(ACO).Methods:The patients with asthma,COPD,or ACO admitted to the respiratory department of ourhospital from March 2017 to October 2018.They were enrolled consecutivelyin chronological order,with 20 cases in each group.General information of subjects,such as age,gender,smoking status,body mass index(BMI)and allergy status,were collected.Lung function,FeNO,and blood routine examination were completed.The expression of IL-6 and IL-8 in plasma were detected by enzyme-linked immunosorbent assay(ELISA).Statistical analysis was performed using SPSS 22.0software.One-way ANOVA was used for the differences of measurement databetween the groups,thechi-square test for comparing count data,Pearson correlation analysisfor correlation analysis,and the receiver operating characteristics(ROC)for evaluating diagnostic value of the four biomarkers for distinguishing ACO and asthma,and/or COPD.Results:(1)There were significant differences in gender,smoking,allergy and lung function data among the four groups(P<0.05).(2)There was a statistically significant difference in IL-6 level among the therr groups(P=0.014).The IL-6 level was higher in patients with COPD than in patients with asthma and ACO [2.28(1.70-2.65)pg/ml vs.1.50(1.18-1.84)pg/ml vs.1.89(1.45-2.01)pg/ml].(3)There was a significant difference in IL-8levelamong the three groups(P=0.008),and the IL-8 levelof COPD group was significantly higher than those of asthma and ACO groups [0.93(0.80-1.04)pg/ml vs.0.83(0.80-0.86)pg/ml vs.0.84(0.80-0.89)pg/ml].(4)There was a significant difference in Eos number among the three groups(P=0.008).The Eos number of asthma group was significantly higher than those of COPD group [585(140-720)/ul vs.231(110-200)/ul],but no statistical difference compared with that of ACO group [403(270-560)/ul,P>0.05].(5)There was a statistically significant difference in FeNOlevel between asthma,COPD and ACO groups(P=0.015).TheFeNO level of COPD group was significantly lower than those of asthma and ACO group [20.00(13.00-27.00)ppb vs.33.40(20.80-42.00)ppb vs.30.80(20.00-39.30)ppb].(6)The IL-8 level was negatively correlated with the FeNO value(r=-0.288,P=0.026),and positivelycorrelatedwith IL-6 level((r=0.351,P=0.006).TheFeNO value was positively correlated with the Eos number(r=0.399,P=0.002).(7)There was a best diagnostic performanceof the combined four biomarkers for identifying ACO and asthma,with the area under ROC curveof 0.810,the sensitivity of 0.700,and the specificity of 0.800.(8)There was a best diagnostic performanceof the combined three biomarkers including IL-8,FeNO and Eos count for identifying ACO and COPD,withthe area under the ROC curve of 0.790,the sensitivity of 0.800,and the specificity of 0.800.(9)There was a best diagnostic performanceof the combined two biomarkers including IL-6 and FeNO for identifying Asthma and COPD,withthe area under the ROC curve of 0.840,the sensitivity of 0.900,and the specificity of 0.700.Conclusion:It is difficult to effectively distinguish ACO from asthma/COPD by any indicator of IL-6,IL-8,FeNO and Eos.The combined detection of these four biomarkers can significantly improve the positive rate of ACO differential diagnosis.