Comparison of three current viral load assays for the quantitation of human immunodeficiency virus type 1 RNA in plasma
Related Experiment Video
Updated: Aug 22, 2026
Amplifying and Quantifying HIV-1 RNA in HIV Infected Individuals with Viral Loads Below the Limit of Detection by Standard Clinical Assays
Published on: September 26, 2011
Antigoni Katsoulidou1, Eleni Papachristou, Maria Petrodaskalaki
1Department of Hygiene and Epidemiology, Athens University Medical School, 75 Mikras Asias Street, GR-115 27 Athens, Goudi, Greece. ahatzak@med.uoa.gr
Insights
The LCx HIV RNA assay demonstrates strong correlation and high agreement with established bDNA 3.0 and Monitor v1.5 tests for quantifying HIV viral load in patients. This comparison validates LCx as a reliable tool for HIV RNA monitoring.
Area of Science:
- Clinical Virology
- Molecular Diagnostics
- Infectious Diseases
Background:
- Accurate quantification of Human Immunodeficiency Virus (HIV) RNA is crucial for monitoring disease progression and treatment efficacy.
- Several quantitative assays exist, necessitating comparative studies to establish performance and reliability.
- The LCx HIV RNA assay is a newer method requiring validation against established standards like Versant HIV-1 RNA 3.0 (bDNA) and COBAS Amplicor HIV-1 Monitor v1.5.
Purpose of the Study:
- To compare the performance of the LCx HIV RNA quantitative assay against two established HIV RNA assays: Versant HIV-1 RNA 3.0 (bDNA) and COBAS Amplicor HIV-1 Monitor v1.5.
- To evaluate the detection range, overall agreement, and correlation of the LCx assay with the reference assays using clinical plasma samples.
- To determine the clinical utility of the LCx assay for monitoring HIV viral load.
Main Methods:
- Plasma samples from HIV-1-infected patients with varying viral load levels were analyzed.
- The LCx HIV RNA assay was directly compared with the Versant HIV-1 RNA 3.0 (bDNA) assay and the COBAS Amplicor HIV-1 Monitor v1.5 test.
- Key performance metrics including detection range, overall agreement, and correlation coefficients (r) were calculated, with a lower limit of linear range set at 50 copies/ml.
Main Results:
- The LCx assay showed strong correlation with both bDNA 3.0 (r = 0.96) and Monitor v1.5 (r = 0.96) assays.
- High overall agreement was observed: 93.4% with bDNA 3.0 and 91.2% with Monitor v1.5 at a 50 copies/ml cut-off.
- The LCx assay demonstrated robust detection ranges, comparable to the established assays, with specific regression equations detailing the relationships between the assays.
Conclusions:
- The LCx HIV RNA quantitative assay exhibits excellent performance characteristics, including high correlation and agreement with established HIV RNA assays.
- The LCx assay is a reliable and accurate tool for the quantification of HIV viral load in clinical settings.
- These findings support the use of the LCx assay for effective patient management and monitoring of HIV infection.
Abstract:
The LCx HIV RNA quantitative assay (Abbott Laboratories, Delkenheim, Germany) was compared with the Versant HIV-1 RNA 3.0 (bDNA) assay (Bayer, Tarrytown, NY) and the COBAS Amplicor HIV-1 Monitor v1.5 test (Roche Diagnostics, Branchburg, NJ), using plasma samples of various viral load levels from HIV-1-infected patients. Considering the lower limit of the linear range of 50 copies/ml of both assays, the detection range of the LCx was 127/151 (84.1%) versus the 131/151 (86.8%) of the bDNA 3.0 assay, while overall agreement between the two assays was 93.4% (141/151). LCx and bDNA 3.0 results were found to be strongly correlated (r = 0.96). The fitted regression line was described by the equation log10(LCx copies/ml) = 0.05 + 1.06 x log10(bDNA 3.0 copies/ml) with 95% CI for the estimated slope and intercept at 1.01, 1.12 and -0.16, 0.26, respectively. Similarly, the detection range of the LCx was 115/148 (77.7%) versus the 128/148 (86.5%) of the Monitor v1.5 test. A 91.2% concordance (135/148) was observed between these two assays at a cut-off of 50 copies/ml. LCx and Monitor v1.5 results were highly correlated (r = 0.96). The fitted regression line was described by the equation log10(LCx copies/ml) = 0.06 + 1.03 x log(10)(Monitor v1.5 copies/ml) with 95% CI for the estimated slope and intercept at 0.97, 1.09 and -0.16, 0.28, respectively.
