INTRATHECAL PRODUCTION OF INTERLEUKIN-12 AND GAMMA-INTERFERON IN PATIENTS WITH BACTERIAL-MENINGITIS

To assess the role of interleukin-12 (IL-12) and gamma interferon (IFN -gamma) in children with bacterial meningitis, bioactive IL-12 (p70) a nd the inactive subunit p40 and IFN-gamma were measured in serum and c erebrospinal fluid (CSF) from 35 children with bacterial meningitis an d 10 control subjects, The production of IFN-gamma is induced by IL-12 with tumor necrosis factor alpha (TNF-alpha) as a costimulator and in hibited by IL-10, CSF concentrations of IL-12 p40 as well as those of IFN-gamma were markedly elevated, whereas IL-12 p70 was hardly detecta ble, Detectable CSF levels of IFN-gamma correlated positively with IL- 12 p40 (r = 0.40, P = 0.02) and TNF-alpha (r = 0.46, P = 0.04) but not with IL-6, IL-8, or IL-10, In contrast to CSF levels of TNF-alpha, IL -12, and IL-10, those of IFN-gamma were significantly higher in patien ts with pneumococcal meningitis than in children with meningitis cause d by Haemophilus influenzae and Neisseria meningitidis, presumably bec ause of a high CSF TNF-alpha/IL-10 ratio in the former, We suggest tha t IL-12- and TNF-alpha-induced IFN-gamma production may contribute to the natural immunity against microorganisms in the CSF compartment dur ing the acute phase of bacterial meningitis.