The genetic divergence of HIV-1 group O is high relative to pandemic group M, which could impact detection and quantification of plasma RNA. Recent commercial kits for RNA quantification seem to show good performances in HIV-1/O, but discrepancies are still observed. Here, we compare the performances of 3 commercial assays for the RNA quantification of HIV-1/O.
We studied the RNA quantification of 117 clinical samples using Abbott RealTime HIV-1, Cepheid Xpert HIV-1 Viral Load, or Roche Cobas TaqMan HIV-1 v2. First, we conducted a qualitative description, and second, we focused on a quantitative analysis of the results above 40 cp/mL. The degree of agreement between methods and the strength of the correlation of viral load determination were estimated using Bland–Altman plot and Passing–Bablok regression with the Spearman coefficient, respectively.
Our 2-by-2 analysis showed that the Abbott and Cepheid assays were very close in terms of correlation and dispersion of points, whereas Roche presented higher values in the highest range of quantification (>5 log10). The Cepheid assay combined better correlation with the consensus value and a lower dispersion of values, leading to an overall better performance of quantification. The quantification was still impacted by intragroup genetic diversity with, here, 1 strain (YBF26).
Using a new approach to compare the performances of RNA quantification between more than 2 techniques, we demonstrated that Cepheid could be the most suitable assay for HIV-1/O quantification, although the results from all assays remained strain dependent.