Serum procalcitonin levels in bacterial and abacterial meningitis

Abstract

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. Prospective case series. Tertiary care center. 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. Blood and cerebrospinal fluid samples. 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. 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.