Comparison of the Hologic Aptima HIV-1 Quant Dx Assay to the Roche COBAS Ampliprep/COBAS TaqMan HIV-1 Test v2.0 for the quantification of HIV-1 RNA in plasma samples.

- Aptima HIV Quant Dx and CAPCTMv2 HIV tests for measuring HIV-1 RNA were compared.
- The two tests were highly correlated, sensitive and inclusive.
- Minor differences in linear response between the two tests were detected.
- A high agreement between tests at clinical decision levels was observed.
- Both tests are useful for monitoring patients with HIV-1 infection.

BackgroundHIV-RNA is the most important parameter for monitoring antiviral treatment in individuals infected with HIV-1. Knowledge of the performance of different tests for the quantification of HIV-1 RNA is therefore important for clinical care.ObjectivesTo compare the analytical performance of the Aptima HIV-1 Quant Dx Assay (Aptima) and the COBAS Ampliprep/COBAS TaqMan HIV-1 Test v2.0 (CAPCTMv2) for the quantification of HIV-1 RNA in plasma samples.Study designThe performance of the two tests was compared on 216 clinical plasma samples, on dilutions series in seven replicates of five clinical samples of known subtype and on ten replicates of the Acrometrix High and Low Positive Control.ResultsBland-Altman analysis of 130 samples that quantified in both tests did not show indications of gross mis-quantification of either test. A tendency of the Aptima assay to quantify higher at high viral load compared to the CAPCTMv2 was observed in Bland-Altman analysis, by Deming regression (Slope 1.13) and in dilution series of clinical samples. Precision evaluated using the Acrometrix Positive Controls was similar for the High Control (CV: 1.2% vs. 1.3%; Aptima assay vs. CAPCTMv2 test, respectively), but differed for the Low control (CV: 17.9% vs. 7.1%; Aptima assay vs. CAPCTMv2 test, respectively). However, this did not impact clinical categorization of clinical samples at neither the 50 cp/mL nor 200 cp/mL level.ConclusionThe Aptima assay and the CAPCTMv2 test are highly correlated and are useful for monitoring HIV-infected individuals.