Comparison of C Reactive Protein and Procalcitonin Levels in Cerebrospinal Fluid and Serum to Differentiate Bacterial from Viral Meningitis.

GOALS: It is unclear whether C reactive protein (CRP) and procalcitonin (PCT) levels in cerebrospinal fluid (CSF) improve the accuracy compared to their serum levels for the differential diagnosis of infectious meningitis. The aim of this study was to compare the accuracy of CRP and PCT levels in CSF and serum in order to differentiate between bacterial and viral meningitis. PROCEDURES: CRP and PCT levels were measured in CSF and serum from patients with bacterial or viral meningitis. The diagnostic accuracy was determined using receiver operating characteristic curves (ROC), calculating the area under the ROC curve (AUC). RESULTS: Thirty patients were included in this study, 18 of whom had bacterial meningitis and 12 viral meningitis. The AUCs to differentiate bacterial from viral meningitis using serum CRP, CSF CRP, serum PCT and CSF PCT were 0.926; 0.898; 0.963; and 0.694 respectively. Serum CRP and PCT exhibited 100% and 88.9% sensitivity, 83.3% and 100% specificity with a cut-off =14.0 mg/L and 0.18 μg/L respectively. CONCLUSIONS: Levels of CRP and PCT in CSF did not present greater accuracy in differentiating bacterial from viral meningitis compared to serum levels. Serum CRP and PCT showed a high diagnostic accuracy, therefore its quantification is recommended in all patients with suspected infectious meningitis.