Diagnostic capability of CSF ferritin in children with meningitis

The current study was performed to determine the normal cerebrospinal fluid (CSF) ferritin level according to age and cut-off value for early diagnosis of bacterial menignitis. The subjects (N = 203) consisted of children who received the CSF examination at Department of Pediatrics in Chonnam National University Hospital between May 1996 and July 2001. The subjects were classified into four groups; non-meningitis, viral meningitis, bacterial meningitis, and bacterial meningitis suspected group. CSF ferritin of the meningitis group was significantly higher than that of the non-meningitis or viral meningitis groups. CSF ferritin had positive correlation with white blood cell (WBC) count and protein in CSF but negative correlation with CSF glucose (P < 0.01). CSF ferritin decreased progressively up to 1 year but such a tendency was not evident in patients over 1 year in age in the non-meningitis group. For early diagnosis of bacterial meningitis, 15.6 ng/mL was considered as the appropriate cut-off value of CSF ferritin (a sensitivity of 96.2% and a specificity of 96.6%).