HIV-1 RNA quantitation in plasma, or virus load testing, is the primary method by which the response to antiretroviral therapy is monitored. In the current study, we describe evaluation of the Aptima® HIV-1 Quant Dx assay (Aptima) performed on the automated Panther® system. The clinical performance of Aptima was compared to the COBAS® AmpliPrep/COBAS® TaqMan® HIV-1 Test v2.0 (CAP/CTM) using 162 EDTA plasma samples collected from patients undergoing HIV-1 monitoring. Overall agreement was 84.0% (136/162) with a kappa statistic of 0.723 (Standard Error 0.047; 95% CI 0.630 to 0.815) indicating substantial agreement. Using the 86 clinical samples quantifiable by both methods, Passing-Bablok regression revealed a regression line of Y = 1.069*X – 0.346 [95% CI of the slope (1.003 to 1.139) and intercept (-0.666 to -0.074)] and Bland-Altman analysis demonstrated a mean difference (Aptima-CAP/CTM) of -0.075 log10 copies/mL (95% limits of agreement of -0.624 to 0.475), consistent with negative bias. Comparison of Aptima testing on paired dried blood spot (DBS) and plasma specimens archived from participants in the Peninsula AIDS Research Cohort Study (PARC) demonstrated an overall agreement of 94.7% (90/95) when 1000 copies/mL was used as threshold. In conclusion, the Aptima HIV-1 Quant Dx assay provides a suitable alternative for HIV-1 monitoring in plasma and DBS.
Evaluation of the Aptima HIV-1 Quant Dx Assay using Plasma and Dried Blood Spots.