CALCA and meningeal tuberculosis: Kim et al. compared S–PCT levels in 26 patients with tuberculosis meningitis versus 70 patients with BM and 49 patients with VM in a retrospective study and showed that low S–PCT levels (≤1.27 ng/mL) independently distinguished tuberculosis meningitis from bacterial meningitis, with a 96.2% sensitivity and a 62.9% specificity.