The Correlation Between Peripheral Blood Lymphocyte Count With The Severity Of Acute Exacerbations Of COPD

Objective:This study aimed to analyze the level of peripheral blood lymphocyte count in patients with acute exaerbation of chronic obstructive pulmonary disease（AECOPD）,exploring the relationship between peripheral blood lymphocyte count with the severity of AECOPD,and analyzing the correlation between lymphocytes and inflammatory factors,for providing clinical value for the comprehensive evaluation of AECOPD.Methods:（1）objects and grouping basis:According to the Guidelines for the Diagnosis and Treatment of Chronic Obstructive Pulmonary Disease of china（2021）,we selected patients with acute exacerbation of chronic obstructive pulmonary disease in the Second Affiliated Hospital of Dalian Medical University from August 2020 to November 2022,and then according to the Chinese Expert Consensus on the Diagnosis and Treatment of Acute Exacerbation of Chronic Obstructive Pulmonary Disease（AECOPD）（2017）,patients were divided into the group without respiratory failure（86）and the group with respiratory failure（38）.（2）Analyzing the previous data of all patients,including age,sex,course of disease,smoking index,number of hospitalizations in the previous year,number of hospital days and comorbidities（hypertension,diabetes,coronary heart disease and Charlson comorbidity index）;The included laboratory results included blood counts（total number of white blood cells,neutrophil count and percentage,lymphocyte count and percentage,etc.）,lymphocyte subsets(CD₄⁺T lymphocytes and percentage,CD₈⁺T lymphocytes and percentage,CD₃⁺T lymphocytes and percentage,CD₁₉ lymphocytes,NK cells,CD₄⁺/CD₈⁺values);Inflammatory factors such as CRP,PCT,ESR,SAA,fibrinogen,ferritin,immunoglobulin and arterial blood gas analysis were included.（3）The statistical analysis:The SPSS 25.0 software was used to analyze the clinical data,including general data and clinical indicators;The spearman correlation analysis was used to explore the correlation between CRP with lymphocyte count and related subsets of cells,and then exploring the correlation between Pa CO₂ with lymphocytes which were described by Graph Pad Prism 8.0 software.The logistic multivariate regression was used to analyze the influencing factors of AECOPD,and the receiver operating characteristic（ROC）curve was finally drawn according to the regression analysis results,and the indicators with predictive value were judged by the corresponding area under the curve of each factor,and recording the optimal cut-off value,sensitivity and specificity.Results:（1）The comparison of general data:Compared with the group without respiratory failure,the number of hospitalizations and comorbidities in the group with respiratory failure was statistically significant（P<0.05）;age,course of disease,smoking index,hospital days,hypertension,diabetes,and CHD were not different between the groups（P>0.05）.（2）Blood cells and Lymphocyte subsets:In the patients with respiratory failure,the leukocyte count,lymphocyte count and percentage,platelet count decreased and the percentage of monocytes increased,the difference was statistically significant（P<0.05）,NLR was not statistically significant（P>0.05）;Compared with the patients in the no-respiratory failure group,the levels of CD₄⁺T lymphocytes,CD₈⁺T lymphocytes,CD₃⁺T lymphocytes,CD₁₉ lymphocytes,and the percentage of CD₃⁺T lymphocytes in the respiratory failure group of AECOPD patients were lower,and the difference was statistically significant（P<0.05）.However,the differences of the CD₄⁺/CD₈⁺values and NK cell count were not significant（P>0.05）.（3）Inflammatory factors:The level of CRP in patients with respiratory failure was higher and the difference was statistically significant（P<0.05）,while PCT,ESR,SAA,fibrinogen and ferritin were not statistically significant between the two groups（P>0.05）;（4）Immunoglobulin:The level of Ig A,Ig M,Ig G and Ig E in the two groups were not statistically significant（P>0.05）;（5）The analysis of Arterial blood gas:In patients of AECOPD with respiratory failure,p H and the the oxygenation index was lower,the level of Pa CO₂ was higher,and the difference was statistically significant（P<0.05）;there was no significant difference in c Lac between the two groups（P>0.05）;（6）The diagnostic value of the regression analysis and the receiver operating characteristic（ROC）curve in the severity of AECOPD:Binary logistic regression analysis showed that peripheral blood lymphocyte count（OR=0.247,P=0.023）and CCI score（OR=2.123,P=0.021）were correlated with the severity of AECOPD,and finally lymphocyte count had the highest predictive value for COPD exacerbation through the receiver operating characteristic（ROC）curve.The area under the curve was 0.733（95%CI:0.642-0.823）,the optimal cut-off value was 1.835×10⁹/L,the sensitivity was 40.7%,and the specificity was 97.4%.（7）The spearman correlation analysis showed that CRP was negatively correlated with the peripheral blood lymphocyte count,the level of CD₄⁺,CD₈⁺,CD₃⁺,CD₁₉,and the respective correlation coefficients were-0.308,-0.312,-0.336,-0.346,-0.320（P<0.001）;the level of Pa CO₂ was negatively correlated with the peripheral blood lymphocyte count,the level of CD₄⁺,CD₈⁺,CD₃⁺,CD₃⁺%,CD₁₉（r=-0.296,-0.338,-0.202,-0.301,-0.242,-0.223）,the difference was statistically significant（P<0.05）;Conclusion:The peripheral blood lymphocyte count has a certain predictive effect on the severity of acute exacerbation of chronic obstructive pulmonary disease.The patients of AECOPD with less cellular immunity have a more severe condition,a more severe systemic inflammatory response,and a greater number of comorbidities.