Intrathecal immune activation is associated with cerebrospinal fluid markers of neuronal destruction in AIDS patients

We analysed the relationship between cerebrospinal fluid (CSF) concentratio ns of the light subunit of the neurofilament protein (NFL, a marker of neur ons, mainly axons), neopterin (a marker of immune activation), and quantita tive HIV RNA levels in 47 patients with HIV-1 infection, 25 of whom had AID S. In the AIDS patients, the mean levels of CSF NFL were high indicating ne uronal destruction. The CSF NFL and the CSF neopterin concentrations were c orrelated in the subgroup of patients without CNS opportunistic infection ( p < 0.05). There was no significant correlation between NFL and HIV RNA lev els in CSF. In HIV seropositive patients without AIDS, only 3/22 had CSF NF L concentrations above the upper normal reference value. The results sugges t that CNS neuronal destruction occurs frequently in patients with AIDS but rarely in those without AIDS, and that immune activation rather than the H IV viral load is associated with neurochemical signs of axonal destruction. (C) 2000 Elsevier Science B,V. All rights reserved.