The initial serum concentrations of calprotectin and calgranulin C were significantly higher in patients with BS (n = 66) than in those with viral infections (n = 24) and the healthy controls (n = 26); the level of calprotectin was found to be the best predictor of BS, followed by the neutrophil-lymphocyte count ratio (NLCR) and the level of procalcitonin (PCT).