Quinolinic acid and lymphocyte subsets in the intrathecal compartment as biomarkers of SIV infection and simian AIDS

Cerebrospinal fluid (CSF) samples were collected from monkeys infected with SIVmac251 (SIV) Or HIV-1/SIVmac chimeric viruses (SHIVHXBc2 and SHIV89.6P) to investigate quinolinic acid (QUIN) levels in the intrathecal compartment. CSF levels of QUIN were elevated in the SIV-infected monkeys, especially in animals with end-stage disease, and in those infected with pathogenic SHIV89.6P, but not after infection with the nonpathogenic construct SHIVHXBc2 QUIN elevations occurred in association with reduced CD4(+) and increased CD8(+) lymphocytes, cellular alterations that were more pronounced in CSF than in the blood. These findings support the view that the intrathecal compartment provides a unique window on viral infection, and are in keeping with the a priori prediction that QUIN increases primarily in response to more pathogenic viral strains.