Elevated Plasma Stromal-Cell-Derived Factor-1 Protein Levels Correlate with Severity in Patients with Community-Acquired Pneumonia

BACKGROUND The aim of this study was to investigate differential changes in plasma levels of stromal-cell-derived factor-1 (SDF-1) before and after antibiotic treatment in patients with community-acquired pneumonia (CAP) and observe the association between the severity of CAP and the plasma SDF-1 level. METHODS We gathered blood specimens from 61 adult CAP patients before and after antibiotic treatment and from 60 healthy controls to measure the plasma concentrations of SDF-1 by using an enzyme-linked immunosorbent assay. RESULTS The plasma SDF-1 concentration was elevated significantly in patients with CAP before receiving treatment compared with the controls and decreased significantly after the patients received treatment. Leukocyte (WBC) and neutrophil counts and C-reactive protein (CRP) levels decreased significantly after antibiotic treatment. Moreover, differences in the plasma concentration of SDF-1 were significantly correlated with PSI, CURB-65, and APACHE II scores (r = 0.389, P = 0.002, and n = 61; r = 0.449, P < 0.001, and n = 61; and r = 0.363, P = 0.004, and n = 61, resp.). CONCLUSIONS An elevated plasma SDF-1 concentration can be used as a biological marker for the early diagnosis of CAP and for the early detection of its severity.