EARLY SUPPRESSION OF VIREMIA BY ZDV DOES NOT ALTER THE SPREAD OF FELINE IMMUNODEFICIENCY VIRUS-INFECTION IN CATS

Prophylactic zidovudine (ZDV) therapy in feline immunodeficiency virus (FIV) inoculated cats was evaluated for 12 months postinfection (pi) and 11 months post drug treatment. Plasma FIV antigenemia was prevente d in six of six ZDV-treated and none of six untreated cats during the initial phase of infection. The present study is a continuation of tha t earlier work. CD4 lymphocyte numbers from ZDV-treated cats were high er than in the untreated cats. CD8 lymphocytes numbers were maintained within control limits in the ZDV-treated cats, while they declined in the untreated cats. Anti-FIV antibody titers were comparable between the ZDV-treated and the untreated cats. Histologically, lymphoid tissu es for the untreated and ZDV-treated cats were unremarkable and simila r to those of the uninfected control cats. Low-level FIV antigen was d etected by enzyme-linked immunosorbent assay in thymus or lymph node h omogenates from 3 of 11 cats tested. Polymerase chain reaction analysi s showed FIV DNA in blood, lymph node, bone marrow, spleen, thymus, an d brain from FIV-inoculated cats irrespective of ZDV treatment. Theref ore, while prophylactic ZDV treatment prevented detectable plasma anti genemia and FIV-induced CD8 lymphocyte decline, it did not slow infect ion of tissues and blood cells of FIV-inoculated cats.