SOLUBLE TUMOR-NECROSIS-FACTOR (TNF) RECEPTORS CONSERVE TNF BIOACTIVITY IN MENINGITIS PATIENT SPINAL-FLUID

The content of tumor necrosis factor (TNF)-alpha antigen and the bioac tivity of soluble TNF receptor type II (sTNF-RII) in cerebrospinal flu id (CSF) from 29 patients with meningeal symptoms and fever were exami ned, Immunoreactive TNF was demonstrated in CSF from 4 of 7 patients w ith bacterial meningitis. In 3 of 8 patients with aseptic meningitis, CSF also contained TNF, but TNF bioactivity was confined to samples fr om patients with bacterial meningitis. Bioactive TNF was exclusively i n high-performance liquid chromatography fractions containing 30- to 6 0-kDa proteins. Lipopolysaccharide induced down-regulation, possibly a fter shedding of granulocyte surface membrane TNF-RII. Consistently, t here was a statistically significant correlation between sTNF-RII and CSF leukocyte counts, Bioactive TNF was found only in CSF containing > 1 ng of sTNF-RII/mL; samples without TNF bioactivity contained less sT NF-RII, Thus, a stabilizing effect of sTNF-RII on the oligomeric cytok ine in vivo is plausible.