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

Abstract

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 (≥300 copies/ml) with the Generic HIV viral load® assay; and samples (n = 24) from untreated individuals infected with HIV‐1 but showing undetectable (me 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. J. Med. Virol. 86:52–57, 2014.