The Value Of Multiple Biomarkers In Evaluating The Severity And Prognosis Of Community-acquired Pneumonia

Objective:To study the value of various serum biomarkers in evaluating the severity and prognosis of community-acquired pneumonia（Community-acquired pneumonia,CAP）,and to provide new ideas for diagnosis and treatment.Methods:A total of 235 patients with CAP admitted to the second Department of Respiratory and critical Medicine,the first affiliated Hospital of Jilin University from June 2020 to December 2021 were collected.Basic information such as age,sex,smoking history,concomitant basic diseases and vital signs were collected.The levels of white blood cell（White blood cell,WBC）,neutrophil（neutrophil,NEU）,neutrophil/lymphocyte ratio（Neutrophil-lymphocyte ratio,NLR）,platelet /lymphocyte ratio（Platelet-lymphocyte ratio,PLR）,C-reactive protein（C-reactive protein,CRP）,procalcitonin（procalcitonin,PCT）,fibrinogen（Fibrinogen,FIB）,D-Dimer（D-Dimer）,erythrocyte distribution width（red blood cell distribution width,RDW）,mean platelet volume（mean platelet volume,MPV）,C-reactive protein/albumin ratio（CRP-albumin ratio,CAR）were measured.According to the CURB-65 score,the patients were divided into three groups: low risk group（0 or 1risk factor）,medium risk group（2 risk factors）and high risk group（3 or more risk factors）.The differences of the above indexes among the three groups were compared.Pearson correlation was used to analyze the correlation between the above indexes and CURB-65 score.According to the outcome,the patients were divided into survival group and death group.The differences of the above indexes between the two groups were compared.The receiver operating characteristic curve（Receiver operating characteristic curve,ROC）was used to analyze t the prognostic value of the above biomarkers in patients with CAP.Results:A total of 235 patients with CAP were included in this study,including 131 males（55.7%）and 104 females（44.3%）.According to CURB-65 score,there were 106 patients in low-risk group,55 patients in medium-risk group and 74 patients in high-risk group.There was no difference in sex,smoking history,hypertension,coronary heart disease and diabetes among the three groups（P >0.05）.The older the patients were,the higher the CURB-65 score and the proportion of cerebrovascular diseases were.Compared with the three groups,the more serious the patient’s condition,the higher the levels of WBC,NEU,NLR,PCT,D-Dimer,RDW,MPV and CRP.CURB-65 score was positively correlated with WBC,NEU,NLR,CRP,PCT,D-Dimer,RDW,MPV and CRP,while CURB-65 score was not correlated with PLR and FIB.According to the outcome of the patients,they were divided into two groups:survival group（n=199）and death group（n=36）.There was no difference in smoking history,diabetes mellitus and etiology between the two groups（P > 0.05）.The age of patients in the death group was significantly higher than that in the survival group（P<0.05）.The proportion of female patients in the death group was significantly higher than that in the survival group（P<0.05）.The proportion of patients with hypertension,coronary heart disease and cerebrovascular disease in the death group was higher than that in the survival group（P < 0.05）.The levels of WBC,NEU,NLR and RDW in the death group were higher than those in the survival group.The area under the ROC curve for predicting the risk of 30-day death in patients with CAP,such as WBC,NEU,NLR,RDW and CURB-65 scores.They are 0.650 [95%confidence interval（95%CI=0.551-0.749）],0.662 [95% confidence interval（95%CI=0.569-0.755）],0.660 [95% confidence interval（95%CI=0.571-0.749）],0.720[95% confidence interval（95%CI=0.630-0.809）] and 0.905 [95% confidence interval（95%CI=0.867-0.942）] respectively.When the cutoff value of NLR is more than 7.90,the sensitivity is 72.2% and the specificity is 55.8%.When the cutoff value of RDW is more than 14.25%,the sensitivity is 58.3% and the specificity is 85.4%.Conclusion:（1）the severity of CAP patients is related to NLR,RDW,PCT and D-Dimer,which can be used as a potential index to evaluate the severity of the disease.（2）NLR,PCT and CURB-65 score have the strongest correlation,which can better evaluate the severity of CAP.（3）NLR and RDW have certain value in evaluating the prognosis of CAP.The more serious the condition is and the worse the prognosis is,the greater the value of NLR and RDW is.