Evaluation of the Abbott Real-Time HIV-1 quantitative assay with dried blood spot specimens.

Department of Molecular Biology, University of Siena, Siena, Italy.
Clinical Microbiology and Infection (Impact Factor: 5.2). 01/2009; 15(1):93-7. DOI: 10.1111/j.1469-0691.2008.02116.x
Source: PubMed

ABSTRACT The Abbott Real-Time HIV-1 assay was evaluated for its performance in quantification of human immunodeficiency virus type 1 (HIV-1) RNA in dried blood spot (DBS) samples. In total, 169 blood samples with detectable plasma HIV-1 RNA were used to extract RNA from paired DBS and liquid plasma samples, using the automated Abbott m Sample Preparation System (m2000sp). HIV-1 RNA was then quantitated by the m2000rt RealTime analyser. RNA samples suitable for real-time PCR were obtained from all but one (99.4%) of the DBS samples and HIV-1 RNA was detected in 163/168 (97.0%) samples. The correlation between HIV-1 RNA values measured in paired DBS and plasma samples was very high (r = 0.882), with 78.5% and 99.4% of cases differing by <0.5 and 1.0 log, respectively. Retesting of DBS replicates following 6 months of storage at 2-8 degrees C showed no loss of HIV-1 RNA in a subset of 89 samples. The feasibility of DBS testing coupled with automated sample processing, and the use of a latest-generation FDA-approved real-time PCR-based system, represents an encouraging first step for viral load measurement in reference centres in developing countries where access to antiretroviral therapy is expanding.

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    HIV Clinical Manual, Edited by Nina Singh, Robert W. Shafer, Susan Swingdells, 01/2009: pages 15 pages;
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    ABSTRACT: Background: The current gold standard for infant diagnosis of HIV-1 is the Roche Amplicor Qualitative DNA assay, but it is being phased out. Objective: Compare the Abbott qualitative assay and the Gen-Probe Aptima assay to the gold standard Roche DNA assay using dried blood spots (DBS). Study design: The Gen-Probe Aptima and Abbott qualitative HIV-1 assays were compared to the Roche DNA assay for early infant diagnosis. Specificity and sensitivity were determined for the three assays using DBS from 50 HIV-exposed uninfected infants and 269 HIV-1 infected adults from North Carolina, respectively. All of the negative and 151 of the positive DBS had valid results on the 3 different assays, and an additional 118 positive DBS had valid results on the Roche DNA and Aptima assays. Results: All three assays were very specific. The Roche DNA assay was the most sensitive (96.7%) over a wide range of HIV PVL, including samples with PVL < 400 copies/ml. Restricted to samples with PVL > 400 copies/ml, the Gen-Probe Aptima assay had sensitivity (96.5%) comparable to the Roche DNA assay (98.8%). The Abbott Qualitative assay was the least sensitive and only had sensitivity above 95% among samples with PVL over 1000 copies/ml. Conclusions: The Abbott HIV-1 Qualitative assay was not as sensitive as the comparator assays, so it would not be a useful replacement assay, especially for infants taking antiretroviral prophylaxis. The Gen-Probe Aptima assay is an adequate replacement option for infant diagnosis using DBS.
    Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 06/2014; 60(4). DOI:10.1016/j.jcv.2014.05.012 · 3.47 Impact Factor
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    ABSTRACT: The 2013 WHO antiretroviral therapy (ART) guidelines recommend dried blood spots (DBS) as an alternative specimen type for viral load (VL) monitoring. We assessed the programmatic utility of screening for ARV treatment failure (TF) at 5,000 and 1,000 copies/mL using DBS and dried plasma spots (DPS) with a commonly used VL assay, the Roche COBAS Ampliprep/COBAS TaqManV.2.0 (CAP/CTM). Plasma, DBS, and DPS were prepared from 839 whole-blood specimens collected from patients on ART ≥ six months at three public facilities in Namibia. VL was measured in plasma, DBS and DPS using the CAP/CTM and results were compared using plasma VL as the reference standard. The clinical sensitivity, specificity, Positive and Negative Predictive Value, (PPV and NPV) of DBS were 0.99, 0.55, 0.33 and 0.99, and 0.99, 0.26, 0.29 and 0.99 at ARV TF diagnostic thresholds of 5,000 copies/mL and 1,000 copies/mL, respectively; for DPS, they were 0.88, 0.98, 0.92 and 0.97, and 0.91, 0.96, 0.89, and 0.97 at TF diagnostic thresholds of 5,000 copies/mL and 1,000 copies/mL, respectively. TF prevalence in DBS was overestimated by 33% and 57% at the two thresholds, respectively. A high rate of false-positive results would occur if the CAP/CTM with DBS were used to screen for ARV TF. WHO recommendations for DBS-based VL monitoring should be specific to VL assay version and type. Despite the higher performance of DPS, the programmatic utility for TF screening may be limited by requirements for processing the whole blood at the collection site.
    Journal of Clinical Microbiology 08/2014; 58(11). DOI:10.1128/JCM.02063-14 · 4.23 Impact Factor

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