title: Meningitis in adult patients with a negative direct cerebrospinal fluid examination: value of cytochemical markers for differential diagnosis.
abstract: BACKGROUND
  The objective of this study was to determine the ability of various parameters commonly used for the diagnosis of acute meningitis to differentiate between bacterial and viral meningitis, in adult patients with a negative direct cerebrospinal fluid (CSF) examination.
  
  
  METHODS
  This was a prospective study, started in 1997, including all patients admitted to the emergency unit with acute meningitis and a negative direct CSF examination. Serum and CSF samples were taken immediately on admission. The patients were divided into two groups according to the type of meningitis: bacterial (BM; group I) or viral (VM; group II). The CSF parameters investigated were cytology, protein, glucose, and lactate; the serum parameters evaluated were C-reactive protein and procalcitonin. CSF/serum glucose and lactate ratios were also assessed.
  
  
  RESULTS
  Of the 254 patients with meningitis with a negative direct CSF examination, 35 had BM and 181, VM. The most highly discriminative parameters for the differential diagnosis of BM proved to be CSF lactate, with a sensitivity of 94%, a specificity of 92%, a negative predictive value of 99%, a positive predictive value of 82% at a diagnostic cut-off level of 3.8 mmol/L (area under the curve (AUC), 0.96; 95% confidence interval (CI), 0.95 to 1), and serum procalcitonin, with a sensitivity of 95%, a specificity of 100%, a negative predictive value of 100%, and a positive predictive value of 97% at a diagnostic cut-off level of 0.28 ng/ml (AUC, 0.99; 95% CI, 0.99 to 1).
  
  
  CONCLUSIONS
  Serum procalcitonin and CSF lactate concentrations appear to be the most highly discriminative parameters for the differential diagnosis of BM and VM.
authors.affiliation: Emergency and Intensive Care Units, North Hospital, Centre Hospitalier Universitaire de Saint-Etienne, Saint-Etienne Cedex 2, France. alain.viallon@chu-st-etienne.fr
authors.forename: Alain
authors.initials: A
authors.lastname: Viallon
authors.forename: Nicolas
authors.initials: N
authors.lastname: Desseigne
authors.forename: Olivier
authors.initials: O
authors.lastname: Marjollet
authors.forename: Albert
authors.initials: A
authors.lastname: Birynczyk
authors.forename: Mathieu
authors.initials: M
authors.lastname: Belin
authors.forename: Stephane
authors.initials: S
authors.lastname: Guyomarch
authors.forename: Jacques
authors.initials: J
authors.lastname: Borg
authors.forename: Bruno
authors.initials: B
authors.lastname: Pozetto
authors.forename: Jean Claude
authors.initials: JC
authors.lastname: Bertrand
authors.forename: Fabrice
authors.initials: F
authors.lastname: Zeni
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood / Q000134:cerebrospinal fluid; D002097:C-Reactive Protein / Q000032:analysis; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D002555:Cerebrospinal Fluid / Q000737:chemistry / Q000166:cytology; D002556:Cerebrospinal Fluid Proteins / Q000134:cerebrospinal fluid; D003937:Diagnosis, Differential; D005260:Female; D005947:Glucose / Q000134:cerebrospinal fluid; D006801:Humans; D019344:Lactic Acid / Q000134:cerebrospinal fluid*; D008297:Male; D016920:Meningitis, Bacterial / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D008587:Meningitis, Viral / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D008875:Middle Aged; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood*; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D002556:Cerebrospinal Fluid Proteins; D011498:Protein Precursors; D019344:Lactic Acid; D002116:Calcitonin; D002097:C-Reactive Protein; D005947:Glucose; D015740:Calcitonin Gene-Related Peptide