Objective—To assess plasma viral RNA concentration
in cats naturally infected with feline immunodeficiency
Animals—28 FIV-infected cats.
Procedure—Cats were categorized into 1 of the 3 following
stages on the basis of clinical signs: asymptomatic
(nonclinical) carrier (AC; n = 11), acquired
immunodeficiency syndrome-related complex (ARC;
9), or acquired immunodeficiency syndrome (AIDS;
8). Concentration of viral RNA in plasma (copies per
ml) was determined by use of a quantitative competitive
polymerase chain reaction (QC-PCR) assay. Total
lymphocyte count, CD4+ cell and CD8+ cell counts,
and the CD4+ cell count-to-CD8+ cell count ratio were
determined by use of flow cytometry.
Results—Plasma viral RNA concentration was significantly
higher in cats in the AIDS stage, compared
with cats in AC and ARC stages. Most (5/7) cats in the
AIDS stage had low total lymphocyte, CD4+ cell, and
CD8+ cell counts.
Conclusions and Clinical Relevance—Concentration
of plasma viral RNA is a good indicator of disease progression
in FIV-infected cats, particularly as cats
progress from the ARC to the AIDS stage.
Determination of CD4+ and CD8+ cell counts can be
used as supportive indicators of disease progression.
(Am J Vet Res 2000;61:1609–1613)