Serum procalcitonin levels in bacterial and abacterial meningitis

Crit Care Med. 2000 Jun;28(6):1828-32. doi: 10.1097/00003246-200006000-00024.


Objectives: To test the hypothesis that serum procalcitonin (PCT) levels are elevated in patients with bacterial meningitis and remain within normal limits in patients with abacterial meningitis.

Design: Prospective case series.

Setting: Tertiary care center.

Patients: A total of 30 patients (13 men and 17 women) with a mean age of 52 yrs, having acute bacterial (n = 16) or abacterial (n = 14) meningitis.

Interventions: Blood and cerebrospinal fluid samples.

Measurements and main results: Patients with abacterial meningitis were younger and had a shorter hospital stay. Of 16 patients with bacterial meningitis, 14 were in a septic condition at admission, but only 5 of 14 patients with abacterial meningitis were in a septic condition at admission. At discharge, 12 patients were without symptoms, 9 patients were moderately disabled, and 9 were severely disabled. No patient died. At admission, PCT, C-reactive protein, white blood cell and cerebrospinal fluid leukocyte counts, and cerebrospinal fluid protein and lactate levels were higher and the serum/cerebrospinal fluid glucose quotient was lower in patients with bacterial meningitis as compared with those with abacterial meningitis (p < .001). PCT was the variable with the highest specificity for bacterial infections (100%), but there were false-negative findings in five patients with bacterial meningitis (a sensitivity of 69%). Persistently elevated or increasing PCT levels after 2 days were associated with an unfavorable clinical course.

Conclusions: Our results indicate that PCT is a useful additional variable for distinguishing bacterial from abacterial meningitis. In patients with abacterial meningitis, PCT levels do not increase even in cases of viral sepsis. Elevated PCT levels indicate a bacterial origin with high specificity, but false-negative results can occur.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Calcitonin / blood*
  • Calcitonin Gene-Related Peptide
  • Female
  • Glycoproteins / blood*
  • Humans
  • Male
  • Meningitis, Bacterial / blood*
  • Middle Aged
  • Prospective Studies
  • Protein Precursors / blood*
  • Sensitivity and Specificity


  • CALCA protein, human
  • Glycoproteins
  • Protein Precursors
  • Calcitonin
  • Calcitonin Gene-Related Peptide