Measurement of levels of tumor necrosis factor-alpha and interleukin-1 beta in the CSF of patients with meningitis of different etiologies: utility in the differential diagnosis.

We assayed tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) concentrations in CSF from patients with meningitis of different etiologies and tested the usefulness of these assays for differentiating between pyogenic meningitis and aseptic meningitis of different etiologies. We used a monoclonal-antibody ELISA to test 125 CSF specimens from patients whose cases were classified as follows: pyogenic meningitis (n = 20), viral meningitis (n = 22), self-resolving aseptic meningitis for which no specific diagnosis was made (n = 25), meningitis due to other infectious agents (n = 11), and neoplastic meningitis (n = 5); we also tested normal CSF from healthy patients (n = 20) and those with neurological diseases (n = 22). Levels of TNF-alpha were above 200 pg/mL in 16 of 20 patients with pyogenic meningitis, but not in patients in the other groups. Levels of IL-1 beta were above 100 pg/mL in 15 of 20 patients with pyogenic meningitis and in one patient with a brain abscess. A positive correlation between levels of these cytokines and different inflammatory parameters was noted, whereas an inverse relationship with the duration of symptoms was observed. With regard to diagnosis, measurement of TNF-alpha and IL-1 beta levels showed sensitivities of 84.2% and 78.9%, respectively; specificities of 100% and 99%, respectively; a positive predictive value of 1 and 0.93, respectively; and a negative predictive value of 0.97 and 0.96, respectively.