[Changes of neopterin in cerebrospinal fluid and serum in children with meningitis]

Neopterin is synthesized mainly by monocytes/macrophages and is considered to be a marker for activation of the cellular immune system. In patients with bacterial or aseptic meningitis, elevated neopterin levels in cerebrospinal fluid (CSF) have been demonstrated. We studied the time courses of CSF and serum neopterin in children with meningitis. The CSF neopterin levels on admission were significantly higher in patients with bacterial meningitis (82.4 +/- 37.0 nmol/L) than in those with aseptic meningitis (32.3 +/- 22.1 nmol/L) or in those with non-pleocytotic CSF (6.9 +/- 4.4 nmol/L). The CSF neopterin levels in the patients with bacterial meningitis were remarkably increased (234.5 +/- 100.2 nmol/L) one day after admission, but the serum neopterin levels were not increased. There was no correlation between CSF neopterin levels and CSF cell count or CSF protein, nor between serum neopterin levels and serum C-reactive protein or peripheral leukocyte count. But the CSF neopterin levels one day after admission were related to the period of positive serum C-reactive protein. CSF neopterin levels in patients with bacterial meningitis were increased one day after admission. The levels in two patients with high levels of CSF IFN-gamma and TNF-alpha were remarkably increased. All patients with bacterial meningitis had received treatment with antibiotics and dexamethasone. It has been reported that TNF-alpha enhances the effect of IFN-gamma for neopterin release by macrophages in vitro and that dexamethasone has the same effect on IFN-gamma as TNF-alpha. The present study suggests that elevation of CSF neopterin in bacterial meningitis results from monocytes/macrophages costimulated with IFN-gamma, TNF-alpha and dexamethasone used in treatment.