Neuropathology in cats experimentally infected with feline immunodeficiency virus: a morphological, immunocytochemical and morphometric study.

Neuropathological changes have been described associated with feline immunodeficiency virus (FIV) infection. The objective of our study was to characterize the lesions found in the brain and spinal cord of experimentally FIV-infected cats and to quantify, by morphometric analysis, the intensity of gliosis found in these subjects at different time post infection (pi). The brains and spinal cords appeared grossly normal. Gray matter of cortical and subcortical structures showed a moderate to pronounced gliosis particularly in all cerebral cortex and hippocampus. Morphometric analysis demonstrated that GFAP immunoreactivity was markedly higher in infected animals. Gliosis was present 15 days pi and did not appear to progress during the infection, whereas neuronal changes when present were observed only in long-term infected animals (15-23 months pi). In a large proportion of infected cats a diffuse gliosis of white matter and vacuolar myelinopathy was also present. Despite some discrepancies observed between neuropathological changes in FIV-infected animals and HIV-infected individuals, the presence in the cerebral cortex of cats with FIV infection of alterations similar to those observed in AIDS patients demonstrates that FIV is an interesting animal model particularly that may be useful for clarifying the pathogenesis of neuropathological changes associated with HIV infection.