Evaluation of different antiretroviral drug protocols on naturally infected feline immunodeficiency virus (FIV) cats in the late phase of the asymptomatic stage of infection

Viruses. 2012 Jun;4(6):924-39. doi: 10.3390/v4060924. Epub 2012 May 30.


The aim of this study was to evaluate the efficacy of the antiretrovirals: Zidovudine (ZDV) alone; ZDV + Recombinant Human Interferon-α (rHuIFN-α); ZDV + Lamivudine (3TC) and ZDV + valproic acid (Valp) on naturally feline immunodeficiency virus (FIV)-infected cats, in the late phase of the asymptomatic stage of infection. The follow-up was performed over one year, through clinical evaluation and the determination of viral loads and CD4+/CD8+ ratios. Neurological signs were studied by visual and auditory evoked potentials (VEP, AEP) and the responses were abnormal in 80% of the FIV-infected cats. After one year, an improvement in VEP and AEP was observed in the ZDV + Valp group and a worsening in the group receiving ZDV + rHuIFN-α. The CD4+/CD8+ ratio showed a significant increase (both intra and inter-groups) only in ZDV and ZDV + 3TC, between their pre-treatment and one year values, as well as among the other groups. Viral load only showed a significant decrease in ZDV and ZDV + 3TC groups, when comparing the values at one year of treatment vs. pre-treatment values and when the different groups were compared. In addition, the viral load decrease was significantly more pronounced in the ZDV + 3TC vs. ZDV group. We conclude that ZDV and ZDV + 3TC produce significant reductions in viral load and stimulate a recovery of the CD4+/CD8+ ratio, compared with the other protocols. It is clear that the addition of 3TC resulted in a greater reduction in viral load than use of ZDV as a single drug. Therefore, the combination ZDV + 3TC could be more effective than the sole use of ZDV.

Keywords: 3TC; FIV; ZDV; antiretroviral therapy; rHuIFN-α; retrovirus; valproic acid; visual and auditory evoked potentials.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-HIV Agents / administration & dosage*
  • Anti-HIV Agents / adverse effects
  • Antiretroviral Therapy, Highly Active / adverse effects
  • CD4-CD8 Ratio
  • Cat Diseases / drug therapy
  • Cats
  • Evoked Potentials, Auditory
  • Evoked Potentials, Visual
  • Feline Acquired Immunodeficiency Syndrome / drug therapy*
  • Female
  • Interferon-alpha / administration & dosage
  • Lamivudine / administration & dosage
  • Male
  • Treatment Outcome
  • Viral Load
  • Zidovudine / administration & dosage


  • Anti-HIV Agents
  • Interferon-alpha
  • Lamivudine
  • Zidovudine