The Relationship Between Induced Sputum Eosinophil Levels And ICS Therapeutic Reactivity In Stable COPD Patients

Objective: This study was designed to observe the relationship between induced sputum eosinophil levels and ICS therapeutic reactivity in stable COPD patients,and discuss the correlation between induced sputum eosinophil level and peripheral eosinophil count.Methods: Patients diagnosed with moderate to severe stable COPD in Fenyang Hospital of Shanxi Province from December 2020 to December 2021 were collected as subjects,which were comprehensively assessed as group C or D,all COPD patients who met the inclusion and exclusion criteria underwent sputum induction detection,patients were divided into group A(EOS<2.5%)and group B(EOS≥2.5%)according to the level of induced sputum eosinophil(EOS),40 cases were collected in each group.According to “GOLD 2021” guidelines,the patients in both groups were regularly inhaled Budesonide/Formoterol inhaler 160ug/4.5ug for 3 months,twice a day,with one inhalation each time.Collecting general data(gender,age,body mass index,COPD course,smoking index and number of hospitalizations due to acute exacerbations in the year prior to enrollment)of patients in each group.Recording the percentage of induced sputum EOS,absolute value of EOS in peripheral blood,and lung function(FEV1,FEV1%pred,FEV1/FVC),m MRC score,CAT score before and after treatment,and the number of effective patients,incidence of adverse reactions in each group.Analyzing the correlation between EOS level in induced sputum and EOS count in peripheral blood.Results: 1.There was no statistical difference in gender,age,body mass index,COPD course,smoking index and number of hospitalizations due to acute exacerbations in the year prior to enrollment in both groups(P>0.05).2.There were no significant differences in FEV1(1.25 ± 0.15 vs 1.20 ± 0.17),FEV1%pred(62.70±8.12 vs 61.88±7.11),FEV1/FVC(56.68±6.75 vs 54.49±7.48)between group A and group B before treatment(P>0.05),after treatment,the FEV1(1.49±0.17 vs 1.38±0.20),FEV1%pred(69.47±7.64 vs 65.69±8.44),FEV1/FVC(63.80±5.75 vs 59.57±9.00)of group B were significantly higher than that of group A(P<0.05),The FEV1,FEV1%pred and FEV1/FVC of each group were improved after treatment compared with before treatment(P<0.05).3.There were no significant differences in m MRC score(2.87±0.80 vs 2.92±0.89)and CAT score(24.72±3.58 vs 25.35±4.81)between group A and group B before treatment(P>0.05),after treatment,the m MRC score(1.97 ± 0.73 vs 2.36 ± 0.84)and CAT score(20.43±5.67 vs 23.51±4.97)in group B were significantly lower than those in group A(P<0.05),the m MRC score in each group decreased after treatment compared with before treatment(P<0.05),but the CAT score(24.72 ± 3.58 vs 23.51 ± 4.97)After treatment was not significantly improved in group A(P>0.05),while CAT score(20.43±5.67 vs 25.35±4.81)in group B was significantly decreased after treatment(P<0.05).4.The baseline EOS% of induced sputum was positively correlated with ΔFEV1,Δ FEV1%pred,ΔFEV1/FVC,ΔCAT score(rs values are 0.439,0.258,0.327 and 0.276 respectively,P<0.05),but had no correlation withΔm MRC score(P>0.05).5.The treatment effective rate of the total population was 76.32%,61.54% in group A and 91.89% in group B,the effective rate in group B was significantly higher than that in group A(x2=8.072,P=0.004).6.The incidence of adverse reactions in the total population was 7.79%,12.50% in group A and 2.70% in group B,the incidence of adverse reactions was no significant difference in both groups(x2 =1.385,P=0.239).7.There was a positive correlation between EOS level in induced sputum and EOS count in peripheral blood(rs=0.265,P=0.021),but the correlation was weak.Conclusion: 1.Stable COPD patients with higher levels of induced sputum eosinophil responded better and benefited more from inhaled glucocorticoid therapy.which can effectively improve lung function,reduce the symptoms of breathing and improve quality of life.2.Among stable COPD patients,there was a weak positive correlation between induced sputum EOS level and peripheral blood EOS count,which suggest that elevated peripheral blood EOS could not well reflect increased airway EOS.