Significant impact of non-B HIV-1 variants genetic diversity in Gabon on plasma HIV-1 RNA quantitation

摘要

Evaluations of HIV-1 RNA viral load assays are lacking in Central Africa. The main objective of our study was to assess the reliability of HIV-1 RNA results obtained with three different assays for samples collected in Gabon. A total of 137 plasma specimens were assessed for HIV-1 RNA using the Abbott RealTime HIV-1? and Nuclisens HIV-1 EasyQ? version 2.0 assays. It included HIV-1 non-B samples (n=113) representing six subtypes, 10 CRFs and 18 URFs from patients infected with HIV-1 and treated with antiretrovirals that were found HIV-1 RNA positive (≥300copies/ml) with the Generic HIV viral load? assay; and samples (n=24) from untreated individuals infected with HIV-1 but showing undetectable (300copies/ml) results with the Biocentric kit. For samples found positive with the Generic HIV viral load? test, correlation coefficients obtained between the three techniques were relatively low (R=0.65 between Generic HIV viral load? and Abbott RealTime HIV-1?, 0.50 between Generic HIV viral load? and Nuclisens HIV-1 EasyQ?, and 0.66 between Abbott RealTime HIV-1? and Nuclisens HIV-1 EasyQ?). Discrepancies by at least one log10 were obtained for 19.6%, 33.7%, and 20% of samples, respectively, irrespective of genotype. Most of samples (22/24) from untreated study patients, found negative with the Biocentric kit, were also found negative with the two other techniques. In Central Africa, HIV-1 genetic diversity remains challenging for viral load testing. Further studies are required in the same area to confirm the presence of HIV-1 strains that are not amplified with at least two different viral load assays.