Abstract 310/Session 46
A Comparative Study of HIV-1 RNA Levels Measured by the NucliSens and Quantiplex bDNA Assays in Serial Plasma Samples from Patients on Antiretroviral Therapy
C. C. GINOCCHIO*, S. TETALI, D. WASHBURN, and M. H. KAPLAN. North Shore University Hospital-NYU School of Medicine, Manhasset, NY.
ÿÿÿ Plasma HIV-1 RNA levels were measured by both the bDNA (Chiron Corp.) and NucliSens (Organon Teknika) assays over a 12
month time period on 14 patients enrolled in the VIRACEPT (Agouron Pharm.) clinical trial studies. Of the 178 specimens tested 109
had detectable HIV-1 RNA and 27 had undetectable levels by both methods. The increased sensitivity of the NucliSens assay (100
copies/ml) as compared to the bDNA assay (500 Eqs/ml) allowed for the detection of HIV-1 RNA in 40 additional specimens (22.47 %). The
NucliSens assay detected a sustained rebound in the viral load (VL) in 10 patients sooner than the bDNA assay (range 2 weeks to 5
months). A comparison of the VL results obtained with each assay demonstrated significantly higher values by NucliSens vs. bDNA
(p=<0.001). The ratios of bDNA RNA Eqs/ml to NucliSens RNA copies/ml were as follows: 1: 2.130, for values 1,000-10,000, 1:1.640 for
values >10,000-50,000; 1:2.066 for values >50,000-100,000; and 1:2.308 for v alues >100,000 (mean ratio 1:2.036,
p=<0.001). A linear regression analysis performed indicated a significant relationship between the 2 v ariables (p= <0.0001).
Spearman correlation analysis indicated a highly significant positive correlation between the VL quantitated by the 2 assays (r =
0.907, p= <0.0001). These data indicate that the enhanced sensitivity of the NucliSens assay allows for the earlier detection of
breakthrough, HIV-1 viremia in patients on antiretroviral therapy. These studies also clearly demonstrate that although there is a
significant correlation between, the values obtained by the bDNA and NucliSens assays, the absolute values are significantly different
and should not be used interchangeably when monitoring patient response to antiretroviral therapy. |
