The Value Of NLR And PLR In The Chronic Obstructive Pulmonary Disease With Different Blood Eosinophil Levels

Objective: To investigate the role of neutrophil/lymphocyte ratio(NLR)and platelet/lymphocyte ratio(PLR)in chronic obstructive pulmonary disease(COPD)with different blood eosinophil(EOS)levels.Method: A retrospective analysis was performed on 662 patients with acute exacerbation of COPD and 335 patients with stable COPD admitted to our hospital from June 2008 to November 2020.According to the blood EOS level of patients,they were divided into three groups: EOS ≤ 100/μL group,100/μL<EOS<300/μL group,and EOS ≥ 300/μL group.The differences of basic data,lung function,NLR and PLR among groups were compared,and the correlation between NLR and PLR and lung function was studied.The predictive value of NLR and PLR for COPD exacerbations was analyzed by receiver operating characteristic(ROC)curve.Results:(1)EOS ≥ 300/μL group and EOS ≤ 100/μL group accounted for 8.8%and 60.3% of patients with acute exacerbation of COPD,respectively.In stable period,15.8% and 41.2%,respectively.The median NLR in COPD exacerbation was 3.09,higher than 2.29 in stable COPD(P < 0.05),while there was no significant difference in PLR.(2)NLR and PLR decreased with the increase of EOS in both acute exacerbation and stable stages of COPD.NLR and PLR in acute exacerbation COPD with EOS ≤100/μL group were higher than those in the other two groups(all P < 0.05).NLR in stable COPD with EOS ≤ 100/μL was higher than that in the other two groups,and PLR in EOS ≤ 100/μL group was higher than that in EOS ≥ 300/μL group(all P <0.05).(3)In the EOS ≤ 100/μL group and 100/μL<EOS<300/μL group,NLR in the acute exacerbation stage of COPD was higher than that in the stable phase(P < 0.05),but there was no significant difference between the EOS ≥ 300/μL group.(4)NLR in acute exacerbation was negatively correlated with FVC%,FEV1,FEV1%,FEV1 / FVC,and NLR was negatively correlated with FEV1% at different EOS levels.NLR in stable stage was negatively correlated with FEV1,FEV1% and FEV1 / FVC,and NLR was negatively correlated with FEV1% and FEV1 / FVC in100/μL < EOS < 300/μL group.In the stable period,only the overall PLR was negatively correlated with FVC.(5)ROC curve analysis indicated that the optimal threshold of NLR for predicting acute exacerbation of COPD was 3.37,the sensitivity was 44.9%,the specificity was90.1%,and the area under the curve was 0.685(95%CI: 0.653～0.717,P < 0.001),its predictive ability was better than WBC,NEU%,NEU,but PLR could not predict COPD exacerbation effectively.Conclusion: In COPD patients with different EOS levels,the lower EOS is,the higher NLR、PLR is,and the value of NLR is greater in COPD patients with EOS ≤100/μL.Meanwhile,NLR has certain suggestive value in the acute exacerbation stage of COPD and is related to the severity of lung function,which may be helpful for personalized treatment of COPD patients.