Correlation between levels of RDW,NLR,CRP,D-dimer in peripheral blood and disease severity in patients with community-acquired pneumonia

Xu Hong; Liu Song; Chang Qing

doi:10.3969/j.issn.1672-8521.2025.04.004

Abstract：Objective:To explore the relationship between the levels of red cell volume distribution width(RDW),neutrophil/lymphocyte ratio(NLR),C-reactive protein(CRP),D-dimer in peripheral blood and disease severity in patients with community-acquired pneumonia(CAP).Methods:A retrospective analysis was performed on the clinical data of 62 patients with CAP(CAP group)admitted to the First People's Hospital of Zhengzhou between January 2021 and June 2024.Additionally,30 healthy individuals who underwent health examinations at the same hospital during the same period were selected as the control group.The levels of RDW,NLR,CRP and D-dimer were measured in both groups.CAP patients were further divided into a severe group(n=29)and a non-severe group(n=33)based on their Clinical Pulmonary Infection Score(CPIS).Differences in the levels of RDW,NLR,CRP and D-dimer were compared between the two subgroups.Logistic regression analysis was used to examine the association between these indicators and disease severity,while receiver operating characteristic(ROC)curve analysis was employed to evaluate their predictive value for severe CAP.Results:Compared with the control group,the CAP group showed significantly higher levels of RDW,NLR,CRP,and D-dimer[RDW:(16.43±2.84)%vs.(13.11±1.44)%;NLR:5.21±2.44 vs.1.92±0.58;CRP:(41.76±17.69)mg/L vs.(1.40±0.87)mg/L;D-dimer:(2.03±0.84)mg/L vs.(0.77±0.33)mg/L;t=6.027,7.267,12.454,7.907,respectively;P＜0.001].Among CAP patients,the severe group exhibited higher levels of RDW,NLR,CRP,and D-dimer compared to the non-severe group[RDW:(16.51±2.49)%vs.(15.13±2.72)%;NLR:5.61±2.30 vs.3.98±2.27;CRP:(44.27±17.04)mg/L vs.(31.85±17.86)mg/L;D-dimer:(2.14±0.75)mg/L vs.(1.28±0.70)mg/L;t=2.073,2.804,2.791,4.668,respectively;P＜0.05].Logistic regression analysis showed that RDW,NLR,CRP and D-dimer were all independent risk factors for progression to severe CAP(RDW:OR=2.502,95%CI:1.200-5.217;NLR:OR=5.714,95%CI:1.679-19.453;CRP:OR=2.179,95%CI:1.413-3.361;D-dimer:OR=2.361,95%CI:1.388-4.015;P＜0.05).ROC curves analysis showed that area under the curve(AUC)for RDW,NLR,CRP,D-dimer,and their combination in detection severe CAP were 0.785,0.882,0.881,0.881 and 0.987,respectively(all P＜0.001).The combined detection of all four markers yielded the highest AUC,with high sensitivity and specificity.Conclusions:The levels of RDW,NLR,CRP and D-dimer in the peripheral blood are abnormally increased in CAP patients,and the increase is more significant in severe patients.The combined detection of the four indexes has a good predictive value for severe CAP.