Correlation Between FeNO,Blood Eosinophils,Lymphocytes,PCT And Lung Function In Patients With Asthma-COPD Overlap

Research purposes:By comparing the general data of ACO patients with simple asthma and COPD,the differences of inflammatory cells,PCT,FeNO values and various indexes of lung function in peripheral blood,and the correlation between FeNO and eosinophils,lymphocytes,PCT and lung function in peripheral blood,this study provides valuable reference for clinical identification of ACO patients.Research methods:From the electronic medical record system and medical record room of Henan Provincial People’s Hospital,115 patients with stable COPD,123 patients with chronic persistent asthma,103 patients with stable ACO,and 101 healthy people who were treated in the Department of Respiratory and Critical Care Medicine from June 2017 to June 2021 were collected retrospectively.General data,hematological data,FeNO results and pulmonary function data were collected.The differences of various data of patients in each group were compared,and the correlation between FeNO value and blood eosinophil count,lymphocyte count,procalcitonin,lung function and other indicators was analyzed,as well as the identification and differential diagnosis efficiency of related indicators for ACO.Research results:1.The male proportion of patients in the 1.ACO group was higher than that in the asthma group,and the difference was statistically significant(P<0.05);compared with the COPD group,the difference was not statistically significant(P > 0.05);The mean age of ACO group was higher than that of asthma group(P<0.05),and there was no significant difference between ACO group and COPD group(P > 0.05).As for the proportion of smoking history,the difference between the asthma group < ACO group < COPD group was statistically significant(P < 0.05).There was no significant difference in BMI among the four groups(P > 0.05).Smoking is one of the risk factors of ACO.2.Neutrophil to lymphocyte ratio(NLR): ACO group > COPD group,the difference was statistically significant(P < 0.05);Eosinophil count: asthma group > ACO group > COPD group,the difference was statistically significant(P < 0.05);C-reactive protein(CRP)and procalcitonin(PCT): there was no significant difference between ACO and each group(P>0.05).3.Results of pulmonary function: All indexes of ACO group and COPD group were significantly lower than those of asthma group(P<0.05),but there was no significant difference between ACO group and COPD group(P>0.05).4.FeNO value: COPD group < ACO group < asthma group,the difference was statistically significant(P<0.05).5.In terms of correlation,FeNO value in the ACO group and asthma group had a positive correlation with blood eosinophil count.In the ACO group,r=0.340,P<0.05,and in the asthma group,r=0.626,P<0.05 indicated that FeNO value in each group had no significant correlation with lung function,lymphocyte count and procalcitonin(P>0.05).6.(1)The combination of FeNO and eosinophil counts showed the highest efficacy in identifying patients with ACO from the healthy population,with the cutoff value of 0.515,AUC=0.817,sensitivity of63.1%,and specificity of 86.2%.When FeNO was detected alone,the optimal cutoff for identifying ACO was 24.5ppb,AUC=0.772,sensitivity 53.4%,and specificity 87.1%.Individually tested for eosinophil count,the optimal cutoff was 0.115 ×10^9/L,AUC=0.685,sensitivity 75.7%,and specificity 54.5%.(2)In the differential diagnosis of ACO and asthma,the optimal cutoff value for FeNO alone was33.5ppb,and the AUC was 0.639,with a sensitivity of 68.3% and specificity of 54.4%.The AUC of the eosinophils tested separately was 0.654,and the optimal cutoff value was 0.439×10^9/L.The sensitivity and specificity were 78.0% and 43.7%,respectively.The optimal cutoff for the combination of FeNO and eosinophil counts was 0.665,and the AUC was 0.659,with a sensitivity of 64.2% and specificity of 62.1%.(3)In the identification of ACO and COPD,the optimal cutoff value when FeNO value is tested separately is 29.5ppb,AUC is 0.703,sensitivity is 43.7%,and specificity is 89.6%.The AUC of the eosinophils tested individually was 0.657,and the optimal cutoff value was 0.175×10^9/L.The sensitivity and specificity were 55.3% and 71.3%,respectively.The combined FeNO and eosinophil count AUC was0.735,with an optimal cutoff of 0.446,sensitivity of 64.1%,and specificity of 69.6%.(4)For the identification of asthma and COPD,the optimal cutoff value when the FeNO value is tested separately is 26.5ppb,AUC is 0.807,sensitivity is 58.5%,and specificity is 91.3%.The optimal cutoff value for eosinophil detection alone was 0.205×10^9/L,and AUC was 0.770,with sensitivity of 68.3%and specificity of 73.9%.The combined FeNO and eosinophil count AUC was 0.824,with an optimal cutoff of 0.459,sensitivity of 71.5%,and specificity of 81.7%.Conclusion:1.Pulmonary function in patients with 1.ACO is similar to that in patients with COPD.2.The FeNO value of ACO patients is positively correlated with the blood eosinophil count,which can be used to evaluate the severity of eosinophilic inflammation.3.The combined detection of FeNO and eosinophil counts is of certain value for the early recognition of ACO and its differentiation from asthma and COPD.