Aim To determine whether D-dimer in patients with communityacquired pneumonia (CAP) can predict mortality risk better than standard biomarkers.

Methods White blood cell (WBC), C-reactive protein (CRP) and D-dimer in 129 patients with CAP were analyzed. The recommended Pneumonia Severity Index (PSI) score was used to classify CAP patients into five groups according to the severity of disease (Group PSI I-V), and for predicting mortality. Additionally, the patients were divided in surviving and non-surviving group.

Results White blood cell and CRP were not in correlation with the severity of CAP and the risk of mortality. The correlation between plasma D-dimer and severity of CAP was found (r=0.4993; p less than 0.001). The level of D-dimer was significantly higher in nonsurviving (2498.38±1248.83ng/mL) than in surviving patients (966.44 ± 968.73ng/mL) (p less than 0.001). In predicting mortality risk, D-dimer showed sensitivity of 0.84 (cut of >1538 mg/mL), specificity 0.86 and AUC 0.859 (95%CI; 0.787-0.914). Pneumonia Severity Index in predicting of mortality risk for cut of > PSI III showed sensitivity of 0.92, specificity 0.62 and AUC 0.868 (95%CI; 0.797-0.921). There was no statistical difference between AUC of PSI and D-dimer (delta AUC= 0.00895) (p=0.9005).

Conclusion Coagulation abnormalities were presented in older patients with severe infections and comorbidity. Plasma D-dimer correlated better than standard inflammatory markers with severity of disease and risk of mortality in patients with CAP. In predicting mortality risk, D-dimer did not show difference among the PSI score.