HIV-1 Load Comparison Using Four Commercial Real-Time Assays

Abstract

؊4 ) among each other. Significant differences were also observed within each group of HIV-1 genotype. The global disparity was higher for CRF02_AG than for B subtypes. This study indicates a risk of viral load misestimating or discrepancies between techniques, depending on the HIV-1 subtype, and speaks in favor of using the same assay for the monitoring of HIV-1-infected patients.

HIV-1 Diversity and Its Implications in Diagnosis, Transmission, Disease Progression, and Antiretroviral Therapy

“…This is probably related with the high level of genetic conservation of the integrase gene that this test amplifies (Young et al, 2011). In contrast, bDNA (Versant v3.0) and NASBA (EasyQ) assays are considerably less reliable for accurate viral load measurements across HIV clades (Bourlet et al, 2011;Church et al, 2011;Katsoulidou et al, 2011;Swanson et al, 2007;Tang et al, 2007). In summary, available data indicates that HIV-1 assays targeting the highly conserved pol integrase region of the HIV-1 genome may be subject to less variability than assays targeting the gag gene (Geelen et al, www.intechopen.com HIV-1 Diversity and Its Implications in Diagnosis, Transmission, Disease Progression, and Antiretroviral Therapy 179 2003; Swanson et al, 2005;Swanson et al, 2006;Swanson et al, 2007).…”

“…However, the newer quantitative real-time PCR (qRT-PCR) methods (i.e., m2000rt Abbot Real Time HIV-1 Assay or Cobas AmpliPrep/COBAS TaqMan) showed a higher performance on HIV viral load testing of patients with subtype B as well as patients with non-B subtype infections (Bourlet et al, 2011;Church et al, 2011;Katsoulidou et al, 2011;Swanson et al, 2007;Tang et al, 2007). Abbot Real Time HIV-1 Assay seems to be the only assay prepared to detect all HIV-1 subtypes, several CRFs, as well as group N, and O viruses (Church et al, 2011;Swanson et al, 2007;Tang et al, 2007).…”

“…Several comparative studies have shown that the sensitivity and specificity of viral load assays varies depending on HIV-1 group or subtype, especially in non-B subtypes, complex recombinant forms and groups O, N, and P viruses (Bourlet et al, 2011;Church et al, 2011 Geelen et al, 2003;Gottesman et al, 2006;Holguin et al, 2008;Katsoulidou et al, 2011;Plantier et al, 2009b;Rouet et al, 2010;Scott et al, 2009;Swanson et al, 2005;Swanson et al, 2006;Swanson et al, 2007;Tang et al, 2007;Wirden et al, 2009;Xu et al, 2008). However, the newer quantitative real-time PCR (qRT-PCR) methods (i.e., m2000rt Abbot Real Time HIV-1 Assay or Cobas AmpliPrep/COBAS TaqMan) showed a higher performance on HIV viral load testing of patients with subtype B as well as patients with non-B subtype infections (Bourlet et al, 2011;Church et al, 2011;Katsoulidou et al, 2011;Swanson et al, 2007;Tang et al, 2007).…”

Current concepts in molecular testing

“…This is illustrated by the failure of existing NAT to detect rare HIV mutants [10], specific HCV genotypes [11] and, more frequently reported, viral load assays that sub and overquantify particular genotypes of HCV and HIV [12,13].…”

Establishment of In-House Quantitative Real-Time RT-PCR Assay for HIV-1 Viral Load Measurement: Application to Evaluate Efficacy of ART in Ghanaian Patients in an Urban Setting

“…With decreasing prices for drugs in many countries, therapy monitoring has become more expensive than the treatment itself [17,18], a situation that leads to insufficient therapy monitoring, suboptimal patient management, and increased risk for emergence of drug-resistant virus strains. In addition, because they have been optimized for strains prevalent in the Northern Hemisphere, many commercial tests are not accurate for testing "exotic" HIV-1 subtypes found mainly in developing countries [19]. Moreover, some commercial assays are based on the gag gene, which is too variable for detection of outlier strains [20], and hence consequently in using such assays, certain HIV-1 subtypes and recombinants may not be detected [21,22].…”