Lipopolysaccharide binding protein, interleukin-6 and C-reactive protein in acute gastrointestinal infections: value as biomarkers to reduce unnecessary antibiotic therapy

Several new biomarkers, such as lipopolysaccharide binding protein (LBP) and interleukin-6 (IL-6), have the potential to determine the severity and outcome of infectious diseases. LBP and IL-6 serum levels have not been reported in patients with gastrointestinal infections. The aim of this study was to compare established markers of infection with new markers, such as LBP and IL-6, in patients with acute gastrointestinal infections LBP, C-reactive protein (CRP), white blood cell count (WBC) and IL-6 serum levels were determined in patients with acute viral or bacterial (positive stool cultures) gastroenteritis. The final diagnosis and empiric antibiotic use were recorded. In total, medical data on 88 patients with acute gastroenteritis (22 bacterial, 66 viral or nonspecific) were analyzed. LBP and CRP levels were significantly increased in patients with acute bacterial gastroenteritis [28.5 +/- A 16.5 vs. 15.2 +/- A 11.5 mu g/mL (p < 0.05) and 10.4 +/- A 9.6 vs. 3.8 +/- A 5.5 mg/dL (p < 0.001), respectively]. LBP at a cut-off value of 14.6 mu g/mL and CRP at a cut-off value of 1.7 mg/dL distinguished between bacterial and non-bacterial gastrointestinal infection (receiver operator characteristic analysis). Empiric antibiotic therapy was initiated in 82% of patients with bacterial gastroenteritis and in 27% of patients with viral gastroenteritis. The use of the cut-off values for LBP and CRP determined here would have avoided unnecessary antibiotic therapy in 14 and 11%, of patients respectively. CRP and LBP appear to be superior to IL-6 and WBC as diagnostic markers of bacterial gastrointestinal infection. Cut-off values may be a useful tool to support clinical decision-making on whether or not to initiate empiric antibiotic therapy.