Correlation Between Regulatory T Cells And Th17 Cells Ratio Imblance And Fractional Exhalde Nitric Oxide,and The Value Of Fractional Exhalde Nitric Oxide In Diagnose Asthma

Objective To study of the correlation between the imbalance of Treg/Th17 cells in peripheral blood of patients with bronchial asthma and fractional exhaled nitric oxide(FeNO),to explore the pathogenesis of bronchial asthma and the diagnostic value of FeNO in bronchial asthma.Methods Thirty-three patients were selected from the clinic or inpatient Department of Respiratory Medicine of The People's Hospital of Guangxi Zhuang Autonomous Region,including 17 patients diagnosed bronchial asthma,16 patients diagnosed with chronic cough and non-asthma.The proportion of Treg and Th17 cells in CD4+ T lymphocytes in peripheral blood was determined by flow cytometry(peripheral blood of 12 patients in the asthma group and 11 patients in the chronic cough group was determined by flow cytometry).The level of IL-17 in plasma was determined by ELISA.All people were finished FeNO.Prospective study of the correlation between the imbalance ofTreg/Th17 cells in peripheral blood of patients with bronchial asthma and(FeNO).Results Comparisons between the two groups: there were no significant difference in the proportion of Treg cells in CD4+T lymphocytes in peripheral blood between asthma group and chronic cough group(0.80±0.39%,1.04±0.25%),P=0.091,and the difference was not statistically significant.The proportion of Th17 cells in CD4+T lymphocytes in peripheral blood of asthma group(4.01±2.11%)was higher than that of chronic cough group(0.93±0.75%),P<0.001,the difference was statistically significant.The ratio of Treg/Th17 cells in asthma group(0.24±0.19)was lower than that in chronic cough group(2.55±2.59),P<0.001,the difference was statistically significant.Peripheral blood plasma IL-17 concentration in asthma group(4.6±1.96pg/ml)was higher than that in chronic cough group(3.01±1.97pg/ml),P=0.012,the difference was statistically significant.The level of FeNO(95.53±37.86ppb)in asthma group was higher than that in chronic cough group(26.94±9.84ppb),P<0.001,the difference was statistically significant.The level of FeNO in asthma group was higher than that in chronic cough group.The area under the ROC curve of FeNO level was 0.982,and the optimal critical point was 35.5ppb.Take this point as the threshold,the sensitivity,specificity,positive predictive value and negative predictive value of diagnosis of asthma were 88.89%,93.33%,94.12% and 87.5%,respectively.Correlation analysis: In asthma group,there was no significant correlation between FeNO and the proportion of peripheral blood Tregcells in CD4+T lymphocytes: r=-0.328,P=0.253.FeNO was positively correlated with the proportion of Th17 cells in CD4+T lymphocytes in peripheral blood: r=0.663,P=0.01.FeNO was negatively correlated with the ratio of Treg/Th17 cells: r=-0.757,P=0.002.Conclusions FeNO has a high sensitivity and specificity in the diagnosis of asthma,which can be used to assist the diagnosis of asthma.In patients with asthma,the ratio of Treg/Thl7 cells was declining and was negatively correlated with FeNO.The proportion of Treg/Thl7 cells is out of balance,in which the number of Th17 cells and the expression level of IL-17,a related factor secreted by Th17 cells,are mainly increased,which is involved in the pathogenesis of inflammation in the lungs of asthma.