Increased levels of soluble Fas receptor and Fas ligand in the cerebrospinal fluid of HIV-infected patients

Analyses of serum samples and blood cells have revealed a dysregulation of the Fas/Fas ligand (FasL) system during HIV infection, which may be related to disease progression. As Fas and Fast have been suggested to participate in brain injury in a variety of CNS disorders, the aim of this study was t o determine (1) whether soluble Las and Fast can be detected in cerebrospin al fluid (CSF) samples from HIV-infected patients, (2) whether levels of th ese molecules are related to disease progression, and (3) whether levels of sFasL are related to other laboratory findings, Soluble Fas was detected i n 38 of 56 (68%) and soluble Fas ligand in 17 of 56 (30%) CSF samples from HIV-infected patients. CSF levels of both molecules correlated neither with the CSF-to-serum albumin ratio nor with corresponding serum concentrations . This finding suggests that they are at least in part produced intrathecal ly, Levels of both CSF sFas and sFasL correlated significantly and inversel y with the blood CD4(+) cell counts, suggesting that the intrathecal releas e of both molecules is increased during progression to advanced immunodefic iency.