Accuracy to 2nd International HIV-1 RNA WHO Standard: Assessment of three generations of quantitative HIV-1 RNA nucleic acid amplification tests

Ability of Two Commercially Available Assays (Abbott RealTi m e HIV-1 and Roche Cobas AmpliPrep/Cobas TaqMan HIV-1 Version 2.0) To Quantify Low HIV-1 RNA Levels (<1,000 Copies/Milliliter): Comparison with Clinical Samples and NIBSC Working Reagent for Nucleic Acid Testing Assays

“…Overall, our results on the performance characteristics of these two assays at LVL are aligned with similar data previously reported with clinical samples (20,(29)(30)(31) and with the 2nd international HIV-1 RNA WHO standard (19). In particular, although there is good agreement between the commonly used diagnostic assays for detecting both HIV-1 B and non-B subtypes along the common range of detection (14,15,18,(32)(33)(34), the interassay correlation is lower at the lower limit of quantification (16-18, 21, 30, 31, 35).…”

“…In particular, although there is good agreement between the commonly used diagnostic assays for detecting both HIV-1 B and non-B subtypes along the common range of detection (14,15,18,(32)(33)(34), the interassay correlation is lower at the lower limit of quantification (16-18, 21, 30, 31, 35). Also, the concordance between the samples with detected or not detected VL is rather low (32)(33)(34), with both the clinical samples (11), the 2nd International HIV-1 RNA WHO Standard, and commercial test panels for HIV-1 (16,19,20). In line with a recent multicenter comparison study (31), we observed that interassay concordance for a threshold of 200 copies/ml was much higher (92.20%) than that at the threshold of the clinically relevant value of 50 copies/ml (89.81%).…”

“…In fact, although most studies have shown that the currently available real-time PCR tests are fairly similar, showing high sensitivity, specificity, reproducibility, as well as good correlation in the relatively high range of quantification (13)(14)(15), poor interassay concordance has been well described at LVL (16)(17)(18)(19)(20)(21). This last issue is an important matter of debate regarding the need to establish a univocal and shared definition of VF and other virologic definitions (such as virologic suppression, virologic rebound, and persistent LVL), because if molecular tests are not in perfect agreement, it becomes difficult to define univocal virologic thresholds.…”

Cross-Platform Analysis of HIV-1 RNA Data Generated by a Multicenter Assay Validation Study with Wide Geographic Representation

“…IV-1 RNA quantitation (virus load testing) continues to be an important tool for monitoring HIV-1 infection (16,29), and a number of different commercially available HIV-1 RNA assays are available for this purpose (1,9,10,12,20,21,26,27,28). HIV-1 RNA results are used to determine antiretroviral treatment efficacy, monitor safety and adherence, stratify patients enrolled in clinical trials, and predict virologic outcomes, such as motherto-child transmission, treatment failure, and viral persistence in body compartments.…”

“…HIV-1 RNA results are used to determine antiretroviral treatment efficacy, monitor safety and adherence, stratify patients enrolled in clinical trials, and predict virologic outcomes, such as motherto-child transmission, treatment failure, and viral persistence in body compartments. In recent years, there has been a change in virus load methodologies, from endpoint PCR determinations to real-time PCR (10,21,27). The new real-time PCR methodologies offer a broad range of benefits over the traditional endpoint PCR, including higher precision, full automation with high throughput, expanded reportable range capabilities, and ever-decreasing lower limits of detection (20 to 40 copies/ml).…”