Application Of Induced Sputum Eosinophils Count In Cough Variant Asthma

Objective:To explore the correlation of induced sputum eosinophils count and bronchial provocation test,the clinical practice value of induced sputum eosinophils count in cough variant asthma(CVA).Methods:130 patients with suspected cough variant asthma were selected from in July 2016 to July 2017 in Respiratory clinic of the first hospital of Shanxi medical university,finally 96 patients were diagnosed with CVA and 34 patients were diagnosed without CVA.All the patients accepted the measurement of induced sputum,pulmonary ventilation function,and bronchial provocation test(Astograph method),and compare the clinical basic information,cough symptoms integration,induced sputum counts,minimum dose(Dmin)in 96 patients with CVA.Results:In this study,induced sputum eosinophils count in CVA patients was negatively correlated with bronchial stimulates the quantitative test Dmin value(r =-0.682,P <0.001),and positively correlated with cough symptoms integration(r = 0.751,P <0.001).The value of diagnosis to CVA with induced sputum eosinophils count was determined by the receiver operating characteristic curves(ROC).The Youden’s index was 58.8%,and the optimal cut-off value was 3.105%,the sensitivity was 82.3% and the specificity was 76.5%.The areas under the ROC curve was 0.793(P < 0.001).Conclusion:In patients with cough variant asthma,there is a significant correlation between induced sputum eosinophils level and airway hyperresponsiveness,and severity of cough symptoms.The induced sputum can be used as an auxiliary and important means for the diagnosis of cough variant asthma.