Evaluation of the Alinity m HIV-1 assay for the quantification of HIV-1 RNA plasma viral load in a high-throughput molecular laboratory in South Africa

Abstract Background Regular HIV-1 viral load monitoring forms an essential part of any successful HIV-1 treatment programme. Abbott Molecular recently released the Alinity m HIV-1 assay to be run on the Alinity m System, a fully automated, continuous and random access analyser using ReadiFlex™ technology. Objectives Our study investigated the performance of the Alinity m HIV-1 assay in comparison to the cobas® HIV-1 test in a high-throughput molecular laboratory. Study design We compared the performance of the Alinity m HIV-1 assay with the cobas® HIV-1 test, performed on both the cobas® 4800 and cobas® 6800 systems at three clinically relevant thresholds (50, 200 and 1000 cp/mL). Results Excellent correlation (r = 0.98) and agreement (mean bias 0.004 log10 cp/mL) was achieved between the cobas® 4800 and Alinity m HIV-1 assay. While there was good correlation between the Alinity m HIV-1 assay and the cobas® 6800 (r = 0.99), Bland-Altman analysis indicated that the cobas® 6800 on average measured 0.22 log10 cp/mL higher than the Alinity m HIV-1 assay across the dynamic range. Percentage agreement was excellent at the 200 cp/mL and 1000 cp/mL thresholds and was slightly lower at 50 cp/mL in comparison with the cobas® systems. Conclusions The Alinity m HIV-1 assay compared well with the cobas® HIV-1 test on both the cobas® 4800 and cobas® 6800 systems in a highthroughput molecular laboratory in South Africa, a low- to middle-income country.