title: Cerebrospinal fluid lactate level as a diagnostic biomarker for bacterial meningitis in children.
abstract: BACKGROUND
  Cerebrospinal fluid (CSF) lactate is a potential biomarker for bacterial meningitis in children. To this end, we performed a single-center retrospective cohort study of children from Sao Paulo, Brazil, with CSF pleocytosis to evaluate the ability of CSF lactate to distinguish between children with bacterial and aseptic meningitis. We determined the optimum cutoff point for CSF lactate using receiver-operator curve (ROC) analysis.
  
  
  RESULTS
  We identified 451 children of whom 40 (9%) had bacterial meningitis. Children with bacterial meningitis had a higher median CSF lactate level [9.6 mmol/l, interquartile range (IQR) 3.2-38.5 mmol/l bacterial meningitis vs. 2.0 mmol/l, IQR 1.2-2.8 mmol/l aseptic meningitis]. A CSF lactate cutoff point of 3.0 mmol/l had a sensitivity of 95% [95% confidence interval (CI) 83-99%), specificity of 94% (95% CI 90-96%) and negative predictive value of 99.3% (95% CI 97.7-99.9%) for bacterial meningitis.
  
  
  CONCLUSIONS
  In combination with a validated meningitis clinical prediction rule, the CSF lactate level can be used to distinguish between bacterial and aseptic meningitis in children with CSF pleocytosis.
authors.affiliation: Pediatric Emergency Department, University Hospital, University of Sao Paulo, and Hospital Israelita Albert Einstein, Av, Prof, Lineu Prestes, 2565 Sao Paulo, Brazil. emf2002@uol.com.br.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Mekitarian Filho
authors.forename: Sérgio Massaru
authors.initials: SM
authors.lastname: Horita
authors.forename: Alfredo Elias
authors.initials: AE
authors.lastname: Gilio
authors.forename: Lise E
authors.initials: LE
authors.lastname: Nigrovic