A prospective multicenter study, published in 2007, included 151 patients with bacterial or nonbacterial meningitis and negative initial Gram stains from three teaching hospitals in France and reported laboratory data, including results of CSF analysis (CSF leukocyte count, percentage of CSF leukocyte, CSF/blood glucose ratio, CSF protein), serum CRP, and serum PCT, together with clinical findings and outcomes. Here, CALCA is linked to infectious meningitis.