Cerebrospinal fluid levels of S-100β in children and its elevation in pediatric meningitis

Objective: To describe normal cerebrospinal fluid (CSF) levels of S-100β in children and determine whether CSF S-100β levels are elevated in pediatric meningitis. Design: Cohort study. Setting: Children's teaching hospital. Patients: A total of 141 children (107 controls and 34 meningitis patients). Methods: CSF levels of S-100β were measured in 107 control patients and 34 children with meningitis. S-100β levels were measured in CSF collected from a lumbar puncture to evaluate for meningitis. Patients were classified as controls if they did not have pleocytosis or an organism identified. Patients were classified as having meningitis if there was CSF pleocytosis. Those with meningitis were then categorized as having bacterial or aseptic meningitis. S-100β levels were measured by a commercial luminometric assay. Data are presented as median (interquartile range [IQ]) unless otherwise noted. Measurements and Main Results: Normal CSF S-100β levels were measured in 107 children with a median age of 2.6 months (1.4 months to 1.5 yrs). The median CSF S-100β was 0.71 μg/L (IQ range, 0.48 -1.07) with a tenth to 90th percentile range of 0.35-1.8 μg/L. A correlation was measured between age and CSF S-100β levels in controls, (r2=.04, p=.037). Thirty-four children had meningitis with a median age of 4.0 yrs (2.0 months to 11.8 yrs). Ten were bacterial/mycobacterial, and 24 were aseptic. Children with meningitis had elevated S-100β levels of 1.1 μg/L (IQ range, 0.9 -1.6) compared with control levels of 0.71 μg/L (IQ range, 0.48 -1.07) (p=.0001). Those with bacterial/mycobacterial meningitis had elevated S-100β levels of 1.6 μg/L (IQ range, 0.78 -3.0) compared with controls (p=.002). Children with aseptic meningitis also had S-100β levels of 1.0 μg/L (IQ range, 0.91-1.4), which were elevated compared with controls, (p=.0003). Conclusions: CSF levels of S-100β are elevated in children with meningitis compared with controls.