D-dimer can reflect severity of patients with community-acquired pneumonia and predict prognosis / 中华危重病急救医学

ABSTRACT

Objective To investigate the utility of plasma D-dimer and fibrinogen (FIB) for the severity assessments and predicting the prognosis of patients with community-acquired pneumonia (CAP).Methods The clinical data of patients with CAP admitted to First Affiliated Hospital of Fujian Medical University were retrospectively analyzed.The patients were divided into Ⅰ-Ⅴ level groups according to pneumonia severity index (PSI),and they were divided into non-survivors and survivors according to 30-day prognosis.The data including gender,age,PSI score,platelets count (PLT),white blood cell count (WBC),D-dimer,FIB,and C-reactive protein (CRP) were compared among groups.The correlations between PSI score and D-dimer,CRP as well as FIB were analyzed by Spearman or Pearson correlation analysis.Receiver operating characteristic curve (ROC) was used to assess the prognostic value of these indicators.Results A total of 499 patients with CAP were enrolled with 298 male and 201 female,the average age was (63.4 ± 17.8) years old,and the 30-day mortality was 6.4％ (32/499).There were 77,80,104,162 and 76 patients in PSI Ⅰ-Ⅴ level groups,and there were more male patients in PSI Ⅵ and Ⅴ level groups.There were no significant differences in PLT and FIB among the groups of different PSI levels,but the levels of WBC,D-dimer and CRP were significantly increased as PSI level increased from Ⅰ to Ⅴ (F1 =3.810,x 22 =102.361,F3 =7.070,all P ＜ 0.01).Compared with survivors,the non-survivors were elder (t =-4.773,P ＜ 0.001) with lower PLT (t =3.026,P =0.003)and higher WBC,PSI score,D-dimer and CRP levels (t1 =-2.545,t2 =-8.421,Z3 =-6.947,t4 =-3.770,all P ＜ 0.05).Plasma D-dimer levels in elderly patients (≥ 65 years old) were statistically higher than those in younger patients (＜ 65 years old;Z =-5.338,P ＜ 0.01).It was shown by correlation analysis that PSI score was positively correlated with D-dimer and CRP (r values were 0.475 and 0.260,both P ＜ 0.001),and no correlation was found between PSI score and FIB (r =-0.062,P =0.170).The area under the ROC curve (AUC) for predicting 30-day death of PSI score,D-dimer and CRP was 0.858 [95％ confidence interval (95％CI) =0.802-0.914],0.867 (95％CI =0.812-0.922) and 0.732 (95％CI =0.641-0.823).The combination of D-dimer and PSI score was better than any single indicator for predicting the prognosis with higher AUC up to 0.905 (95％CI =0.867-0.944),all P ＜ 0.001.The sensitivity and specificity for PSI in predicting 30-day death respectively were 78.1％ and 82.4％ with the cut-off of greater than 122,and those for D-dimer were 75.0％ and 82.9％ with the cut-off of greater than 2.10 mg/L,50.0％ and 84.4％ for CRP with the cut-off of greater than 100.50 mg/L.Conclusions D-dimer could well reflect the severity of CAP and be a good indicator for predicting the prognosis.The combination of D-dimer and PSI might improve the accuracy in predicting prognosis.