NEUROLOGICAL ABNORMALITIES ASSOCIATED WITH FELINE IMMUNODEFICIENCY VIRUS-INFECTION

Specific pathogen-free cats were infected with the Maryland strain of FIV (FIV-MD) for the purpose of assessing the effects of FIV infection on the central nervous system (CNS). Two separate studies were perfor med, involving a total of 13 infected cats and six age-matched, sham-i noculated controls. All animals infected with FIV-MD seroconverted by 8 weeks postinfection and virus was recovered from peripheral blood mo nonuclear cells of all infected cats. Ah of the infected animals had l ower absolute CD4(+) cell. counts and decreased CD4(+)/CD8(+) ratios. Virus was recovered from the cerebrospinal fluid (CSF) of certain infe cted individuals, and antiviral antibody and pleocytosis were evident in the CSF of the majority of infected cats. Additionally, virus was r ecovered from tissue explants from the cerebellum, midbrain and brains tem of one sacrificed FIV+ cat. Specific neurological changes included anisocoria, delayed righting reflex and delayed pupillary reflex, as well as delayed visual and auditory evoked potentials, and marked alte rations in sleep patterns similar to those reported for human immunode ficiency virus (HIV)-positive individuals. Histological evaluation rev ealed the presence of perivascular cuffing and glial nodules in FIV-in fected cats. These results indicate that FIV causes an acute neurologi cal disease that closely resembles the early neurological effects of H IV infection in humans and should serve well as an animal model for le ntivirus-induced CNS disease.