UNCONJUGATED PTERIDINES AND NEUROMENINGEA L INFECTIONS

Concentrations of unconjugated pteridines (neopterin, monapterin, biop terin, pterin) were measured in the cerebrospinal fluid (CSF) of 310 p atients, using a high performance liquid chromatography (HPCL) method Our cohort included 209 controls (C), 15 patients with meningism (M), 22 with viral meningitis (VM), 17 with bacterial meningitis (BM), 9 wi th herpetic meningoencephalitis (HME), 2 with tuberculous meningoencep halitis (TME) and 36 with peripheral systemic infections (PI). These m easurements, expressed as nmol/litre, showed a gradation of neopterin concentrations according to the type of infection: 20.1 +/- 6.5 in gro up C; 46.9 +/- 29.9 in group PI; 274.3 +/- 231.7 in group VM; 699.2 +/ - 711.2 in group BM, 1 101.9 +/- 1 107.9 in group HME and 1 169 +/- 1 171.9 in group TME. There was no such gradation with biopterin. Compar isons of means showed that total neopterin concentrations in the patho logy groups were very different from those observed in controls and in the neuromeningeal infections of the PI group. There was no correlati on between the number of lymphocytes and the concentrations of neopter in or biopterin in the CSF. It is concluded that the concentration of neopterin in the CSF is a sensitive but little specific marker of infe ction, independent of CSF cellular reaction. Measuring this concentrat ion makes it possible : 1) to evaluate the status of immune defences ; 2) to predict that a meningitis will become chronic, and 3) to detect a possible parenchymal participation in a meningeal infection.