Correlation Between Blood Cell Count Parameters And Sputum Cell Phenotype In 232 Patients With Asthma

Background:Bronchial asthma(asthma for short)is a heterogeneous disease characterized by chronic airway inflammation involving a variety of cells(such as mast cells,eosinophils,neutrophils,)and cell components.The pathogenesis of asthma is chronic inflammation,airway hyperresponsiveness and airway remodeling.It is usually characterized by extensive and changeable reversible expiratory airflow restriction,resulting in recurrent symptoms such as wheezing,shortness of breath,chest tightness and/or cough.At present,according to the proportion of inflammatory cells in sputum obtained by induced sputum technology,asthma is divided into the following four inflammatory subtypes:eosinophilic asthma(EA),neutrophilic asthma(NA),granulocyte deficient asthma(PGA)and mixed granulocytic asthma(MA).Different inflammatory subtypes of asthma have different pathogenesis,different clinical characteristics and different treatment schemes.Therefore,the classification of inflammatory subtypes in patients with asthma is of great clinical significance to guide the individualization of asthma.Induced sputum detection technology is a non-invasive method that uses hypertonic saline atomization inhalation to induce subjects with no or little sputum to produce sufficient sputum,so as to analyze and study the cells and inflammatory mediators in airway secretions.It is widely used in asthma research.It can not only assist in the diagnosis of asthma inflammatory subtypes,continuous detection and monitoring of disease changes,but also help to guide treatment.However,sputum induction technology needs professional technology and time-consuming experimental steps,so it is necessary to explore new and more simple and convenient experimental methods to replace sputum induction technology to classify asthma inflammatory subtypes.Methods:A total of 232 asthmatic patients were recruited to collect their clinical data.At the same time,each patient completed the following questionnaires:6 asthma control questionnaires(ACQ6),asthma control test questionnaire(ACT),asthma quality of life questionnaire(AQLQ)and hospital anxiety and Depression Scale(HADS).Lung function and blood routine tests were carried out,sputum samples were obtained through induction technology,sputum smears and staining were carried out,asthma inflammatory subtypes were classified according to the proportion of inflammatory cells in sputum induction of asthmatic patients,and the distribution characteristics of inflammatory subtypes of asthmatic patients in Jilin Province were evaluated,The receiver operation characteristic curve and Spearman correlation coefficient were analyzed by statistical method to determine the correlation between clinical parameters.Results:Among the included patients,PGA(52.1%),EA(38.4%),MA(5.2%)and NA(4.3%)respectively.The number of PGA were the greatest,howeverthat of NA were the smallest.A total of 129(55.6%)patients had asthma and chronic obstructive pulmonary disease(COPD)overlap;Compared with patients with asthma only,these patients had a higher proportion of smokers,higher sputum neutrophil count,worse lung function and worse asthma control(P<0.05).Sputum eosinophil/neutrophil count was positively correlated with blood eosinophil/neutrophil count(P<0.01).In order to determine the proportion of sputum eosinophils≥3%,the best cut-off values of blood eosinophil count and exhaled nitric oxide fraction(Fe NO)were 0.2×10~9/L and 30.25ppd curve(AUC=0.744;AUC=0.653,p<0.001).There was no significant difference in AUC between Fe NO and blood eosinophil count(P=0.162),but both showed poor specificity(57%and 49%,respectively).In order to determine the existence of sputum neutrophil ratio≥61%,the optimal critical value of blood neutrophil ratio was 69.3%(AUC=0.691,P=0.0003);However,this showed poor sensitivity(50%).Conclusions:1.PGA was the most common phenotype of inflammatory cell phenotype in Jilin patients included in this study,followed by EA,MA and NA.There are significant differences in clinical manifestations,pulmonary function measurement,questionnaire and inflammatory cell infiltration among asthma inflammatory cell phenotypes.The related results suggest that the pathophysiological processes of different inflammation related cell phenotypes are different.These results reflect the heterogeneity of patients with asthma.2.The high proportion of smokers,poor patient compliance,insufficient treatment and poor asthma control may be the main reasons for the high proportion of asthma-COPD overlap in this study.3.Blood eosinophil and neutrophil counts showed poor specificity and sensitivity in predicting airway eosinophil and neutrophil inflammation.