Presepsin as a novel diagnostic biomarker for differentiating active pulmonary tuberculosis from bacterial community acquired pneumonia

Background: The expression of presepsin in active pulmonary tuberculosis (APTB) is unknown. We observed the expression of presepsin in APTB, and to evaluate the value for discriminating between APTB and bacterial community acquired pneumonia (BCAP). Methods: Consecutive APTB patients who were accurately diagnosed by sputum culture and BCAP patients were enrolled from August 2013 to July 2015. Clinical data were collected, and plasma presepsin concentrations were tested. Receiver operating characteristic (ROC) curves were performed for diagnostic analysis. Results: In all, 133 healthy individuals, 103 APTB and 202 BCAP patients were enrolled. Presepsin concentrations in APTB group (218.0 [146.0, 368.0] pg/ml) were higher than those in the healthy control group (128.0 [101.5, 176.5] pg/mI, P < 0.001), and lower than the concentrations measured in the BCAP group (532.0 [364.0, 852.3] pg/ml, P < 0.001). Simple APTB and miliary tuberculosis patients showed no significant differences in presepsin concentrations. Compared with both Gram-positive and negative bacteria, Mycobacterium tuberculosis caused a limited increase of presepsin. With the cut-off value set at 401 pg/ml, presepsin demonstrated high positive predictive value, allowing initial discriminating between APTB and BCAP. Presepsin combined with CURB-65 score could significantly improve the discrimination ability. Conclusions: Presepsin concentrations in APTB patients were slightly increased, and may be helpful for initial discrimination between APTB and BCAP.