Background The APTIMA HIV-1 Quant Assay is a fully automated quantitative assay being developed on the PANTHER system and based on real-time Transcription-Mediated Amplification technology. This assay is intended for monitoring HIV-1 viral load in plasma specimens using a 0.5 mL sample.

Methods A cohort of 245 clinical specimens from University of Athens Medical School was tested using the COBAS AmpliPrep/COBAS TaqMan HIV-1 Test, v2.0 (Roche Assay) and the APTIMA HIV-1 Quant Assay (APTIMA Assay). The specimens included subtypes A, B, C and G as well as circulating recombinant forms of HIV-1.

Results Using a lower limit of quantitation for the APTIMA Assay of 30 copies/mL, 175 specimens gave results quantifiable for both assays. The correlation between the two assays was excellent (0.98), with a slope of 1.06 and an intercept of –0.13. Sixty-nine specimens gave results that were either detectable but not quantifiable or not detectable in at least one assay. Thirty were not detectable in both assays and 14 were detectable in both assays. The APTIMA Assay detected 13 specimens that were undetectable with the Roche Assay. There were 12 specimens that were detectable with the Roche Assay and undetectable with the APTIMA Assay. One specimen was above the upper limit of quantitation (10,000,000 copies/mL).

Conclusion The APTIMA HIV-1 Quant Assay gave comparable viral load results when compared to the Roche COBAS AmpliPrep/COBAS TaqMan HIV-1 Test, v2.0. The sensitivity of the APTIMA HIV-1 Quant Assay is similar to that of the Roche COBAS AmpliPrep/COBAS TaqMan HIV-1 Test, v2.0.