CALCA and bacterial infectious disease: An observational cohort study by Knudsen et al. included 55 patients with suspected meningitis and compared the diagnostic value of serum sCD163 levels, CRP, and procalcitonin in bacterial infection and meningitis and showed that, although elevated serum sCD163 levels seem to be the most specific biomarker for differentiating between bacterial and non-bacterial disease (specificity 0.91; sensitivity 0.47), the overall diagnostic accuracy of CRP (Area Under the Curve (AUC) = 0.91) and PCT (AUC = 0.87) were superior compared to sCD163.