INTRODUCTION: CD14 is one of the leukocyte differentiation antigens, and is 
present in macrophages, monocytes, granulocytes and their cell membranes. 
Presepsin, namely soluble CD14-subtype (sCD14-ST) is produced by circulating 
plasma proteases activating cleavage of soluble CD14 (sCD14). The aim of this 
study is to investigate the role of Presepsin and the CURB65 scoring system in 
the evaluation of severity and outcome of CAP in an ED.
METHOD: A prospective, observational study was performed in an ED of an 
university teaching hospital from November 2011 to October 2012. A total of 359 
patients with CAP and 214 patients with severe CAP (SCAP) were consecutively 
enrolled. Plasma Presepsin, lactate, serum PCT levels and leukocyte counts were 
measured and CURB65 score were calculated at admission enrollment.
RESULT: Plasma Presepsin levels were significantly higher in SCAP patients than 
in CAP patients (P < 0.0001), increasing correspondingly with the enhancement of 
CURB65 score. Patients with ARDS or DIC had obviously higher plasma Presepsin 
levels than those without ARDS or DIC (all P < 0.0001), and plasma Presepsin 
levels were significantly higher in non-survivors than in survivors at 28-day 
follow-up. In logistic regression analysis, CURB65 score was the independent 
predictor of ARDS, and Presepsin was the independent predictor of DIC, and 
Presepsin and CURB65 score were both the independent predictors of 28-day 
mortality. The AUCs showed Presepsin in combination with CURB65 score in 
predicting ARDS, SCAP and 28-day mortality was superior to Presepsin or CURB65 
score alone ( all P < 0.01), Presepsin was better than CURB65 score and 
leukocyte in predicting DIC ( P < 0.01).
CONCLUSION: Presepsin is a valuable biomarker in predicting severity and outcome 
in CAP patients in the ED and Presepsin in combination with CURB65 score 
significantly enhanced the predictive accuracy.