The Value Of NLR In Chronic Obstructive Pulmonary Disease

Objective(s):To explore the value of NLR in diagnosis of chronic obstructive pulmonary disease.Methods:From January 2018 to December 2019,160 COPD clinical cases(111 acute exacerbations and 49 stable cases)were analyzed retrospectively in the Department of Respiratory Medicine of the Second Affiliated Hospital of Kunming Medical University,which met the diagnostic criteria of COPD proposed by the 2019 Global Initiative on Chronic Obstructive Pulmonary Disease(GOLD)[1].According to the clinical symptoms,lung function and blood routine of the patients,the COPD patients requiring hospitalization are acute exacerbation(AECOPD group)due to the aggravation of cough,phlegm and asthma symptoms.At the same time to our hospital outpatient review,asymptomatic exacerbations of stable COPD patients are stable group(SCOPD group);The group with no abnormal physical examination in the health center is the healthy group.This experiment is divided into two parts.The first part mainly discusses the relationship between NLR and lung function severity of COPD patients.In this part,patients in AECOPD group are divided into mild airflow restriction group(38 cases),moderate airflow restriction group(42 cases)and severe airflow restriction group(31 cases)according to the patient's lung function GOLD score.The difference of inflammatory markers among the three groups and the correlation between NLR and lung function are compared.The second part aims to compare the difference of NLR and traditional inflammatory indexes among AECOPD group,SCOPD group and healthy people group,and to explore the diagnostic value of NLR for COPD and acute exacerbation of COPD.The common clinical indexes such as white blood cells,neutrophils,lymphocytes,C-reactive protein(CRP),procalcitonin(PCT),interleukin-6(IL-6)and the like in each case were collected,NLR values were calculated,and whether there were differences in NLR and other clinical indexes among the groups were compared,and the diagnostic value of NLR for COPD and acute exacerbation of COPD was analyzed through ROC curve.Results:(1)In the first part of the discussion on the relationship between NLR and COPD lung function,? comparison of general data:except for gender,there is no significant difference in age and BMI between the three groups(p>0.05);?relationship between inflammatory indexes and airflow limitation degree:comparing the difference between NLR and clinical commonly used inflammatory indexes among the three groups,the results show that there are differences between NLR in airflow limitation moderate group and airflow limitation severe group.the NLR value in airflow limitation severe group is higher than that in moderate group,and the differences are statistically significant(p<0.05);However,other commonly used inflammatory indicators,such as CRP and PCT,showed no significant difference among the three groups(P>0.05).(2)In the correlation analysis between NLR and lung function,there is a significant correlation(p<0.05)between NLR and FEV1,FVC,FEV1 and FVC in percentage of the predicted value,and the correlation is negative and weak(|r|<0.4),with statistical significance(3)The second part discusses the relationship between NLR and inflammatory state of COPD:? comparison of general data:there are significant differences in age and sex except BMI among the three groups(p<0.05).the age of AECOPD group(74±12 years old)is higher than that of SCOPD group(68±8 years old)and higher than that of healthy people group(63.5±14 years old).moreover,there are significant differences in sex between AECOPD group and SCOPD group(p<0.05),and males are more than females.?the relationship between inflammatory indexes and inflammatory state:the NLR value among the three groups was higher in AECOPD group than in SCOPD group.and higher in SCOPD group than in normal group.there was statistical difference among the three groups(p<0.05);Except white blood cells,the levels of neutrophils,CRP,PCT and IL-6 in the three groups were higher in the AECOPD group than in the SCOPD group,and higher in the AECOPD group than in the healthy group.There was no significant difference between the SCOPD group and the healthy group(P>0.05).The lymphocyte level among the three groups was higher in healthy group than in AECOPD group,and higher in healthy group than in SCOPD group,with statistically significant difference(P<0.05).(4)The second part analyzes the diagnostic value of each inflammatory index for acute exacerbation of COPD.The results show that NLR has the highest diagnostic value with AUC of 0.886 and CI95%(0.834-0.939).CRP,PCT and IL-6 have high diagnostic value,AUC and CI95%are 0.846(0.788-0.904),0.837(0.773-0901)and 0.830(0.768-0.892),respectively.The diagnostic value of neutrophils and leukocytes is relatively low.AUC and CI95%are 0.769(0.699-0.840)and 0.749(0.675-0.823),respectively.The results are statistically significant(P<0.05).Lymphocytes have no diagnostic value(AUC is 0.177).The optimal cutoff values of NLR.CRP,PCT,IL-6,neutrophils and leukocytes for diagnosis of acute exacerbation of COPD and their corresponding sensitivity and specificity are 2.93(79.3%,100%),7.44mg/dl(64.9%,98%),0.0495ng/ml(68.5%,91.8%),6.05pg/ml(62.2%),respectively.95.9%),4.905*109/L(64.9%.93.9%),7.225*109/L(61.3%,85.7%),Jordan index:0.793,0.629,0.603,0.581,0.588,0.47 respectively.Conclusion(s):1.NLR value has certain value in evaluating the pulmonary function of COPD.When COPD patients cannot be examined for pulmonary function,NLR can be used to preliminarily,simply and quickly evaluate the pulmonary function and disease severity of patients.2.The increase of NLR can be used as an inflammatory marker similar to CRP,PCT,etc.to evaluate whether COPD patients have acute exacerbation.NLR may be helpful for early detection of potential acute exacerbations in COPD patients with normal levels of traditional inflammatory markers.3.NLR is related to airflow limitation in COPD patients.