The Correlation Analysis Between Blood Eosinophil Levels And Acute Exacerbations In Chronic Obstructive Pulmonary Disease

Objective To investigate the correlation between blood eosinophil?EOS?levels and clinical features,inflammatory factors,parameters of pulmonary function,corticosteroid use in patients with acute exacerbations of chronic obstructive pulmonary disease?AECOPD?.Factors associated with re-hospitalization within half a year were also discussed.Methods From January 2015 to June 2018,a retrospective cohort was established among the patients diagnosed with AECOPD in the Department of Respiratory Medicine,Guangzhou Red Cross Hospital affiliated to Jinan University.Basic informations,number of acute exacerbations in the past year,results of routine blood tests,blood gas analysis,inflammatory indicators,parameters of pulmonary function and the use of corticosteroid,length of stay and readmission within half a year after being discharged were all collected.All participants were divided into two groups according to their serum EOS levels:eosinophilic group?with EOS percentage?2%?and non-eosinophilic group?with EOS percentage<2%?.SPSS 13.0 software was used to analyze the data and compare the differences between two groups.Multivariate Cox regression analysis was performed so as to identify the factors related to readmission within half a year after hospital discharge.Results A total of 197 patients were included,including 92 patients in the eosinophilic group??2%?and 105 patients in the non-eosinophilic group?<2%?.The temperatures,levels of white blood cells,neutrophis,neutrophil ratio,neutrophil to lymphocyte ratio?NLR?,standard bicarbonate,CRP,PCT,GOLD grades,mMRC scores on admission,and the rates of venous corticosteroids at the time of hospitalization were significantly lower in the eosinophilic group than those in the non-eosinophilic group?P<0.05?.The SpO₂,lymphocytes,lymphocyte ratio on admission and parameters of pulmonary function during hospitalization were significantly higher in the eosinophilic group than those in the non-eosinophilic group?P<0.05?.The length of stay in hospital and re-hospitalization rate within half a year were also significantly shorter?or lower?in the eosinophilic group?P<0.05?.However,no differences were observed in gender,age,height,weight,BMI,history of smoking,smoking index,complications,other vital signs and arterial blood gas analysis,frequency of exacerbation in the previous year?P>0.05?.Multivariate COX regression analysis showed that NLR>5.32,mMRC score were risk factors for AECOPD patients to be hospitalized within half a year,while FEV₁?forced expiratory volume in one second?value before inhalation of bronchodilators a protective one.Conclusion AECOPD patients with higher EOS levels may have relatively better clinical outcome.Therefore,the percentage of the peripheral EOS may be judged as one of the indicative biomarkers to predict exacerbations of COPD patients.Besides,we found that both NLR>5.32and mMRC sore were risk factors for re-hospitalization within half a year in patients with AECOPD,while FEV₁ before inhalation of bronchodilators a protective one.