Quantification of viral ribonucleic acid in plasma of cats naturally infected with feline immunodeficiency virus.
OBJECTIVE
To assess plasma viral RNA concentration in cats naturally infected with feline immunodeficiency virus (FIV).


METHODS
28 FIV-infected cats.


METHODS
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
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.
Goto
Y
Y
Department of Veterinary Internal Medicine, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan.
Nishimura
Y
Y
Mizuno
T
T
Endo
Y
Y
Baba
K
K
Momoi
Y
Y
Watari
T
T
Hasegawa
A
A
Tsujimoto
H
H
D000818:Animals; D018791:CD4 Lymphocyte Count; D016516:CD4-CD8 Ratio; D018414:CD8-Positive T-Lymphocytes / Q000382:microbiology; D002415:Cats; D004279:DNA, Viral / Q000097:blood*; D018450:Disease Progression; D016181:Feline Acquired Immunodeficiency Syndrome / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D016089:Immunodeficiency Virus, Feline / Q000302:isolation & purification*; D018655:Lymphocyte Count; D016133:Polymerase Chain Reaction
D004279:DNA, Viral