Performance of the Xpert HIV-1 Viral Load Assay: a Systematic Review and Meta-analysis

Abstract

Viral load (VL) is the preferred treatment-monitoring approach for HIV-positive patients. However, more rapid, near-patient, and low-complexity assays are needed to scale up VL testing. The Xpert HIV-1 VL assay (Cepheid, Sunnyvale, CA) is a new, automated molecular test, and it can leverage the GeneXpert systems that are being used widely for tuberculosis diagnosis. We systematically reviewed the evidence on the performance of this new tool in comparison to established reference standards. A total of 12 articles (13 studies) in which HIV patient VLs were compared between Xpert HIV VL assay and a reference standard VL assay were identified. Study quality was generally high, but substantial variability was observed in the number and type of agreement measures reported. Correlation coefficients between Xpert and reference assays were high, with a pooled Pearson correlation (n = 8) of 0.94 (95% confidence interval [CI], 0.89, 0.97) and Spearman correlation (n = 3) of 0.96 (95% CI, 0.86, 0.99). Bland-Altman metrics (n = 11) all were within 0.35 log copies/ml of perfect agreement. Overall, Xpert HIV-1 VL performed well compared to current reference tests. The minimal training and infrastructure requirements for the Xpert HIV-1 VL assay make it attractive for use in resource-constrained settings, where point-of-care VL testing is most needed.

Detection of Antiretroviral treatment failure among adult HIV-1 patients on anti-retroviral therapy for 12 +/- 3 months attending different Voluntary Counseling Testing and treatment centers in Khartoum state, Sudan

“…In Sudan, Gene Xpert was approved by WHO and introduced as a tool for TB/ HIV-1 diagnosis and monitoring respectively. It is rapid and less complexity assay (18) The present study result was similar to many studies results that showed low number of unsuppressed viral load patients. As in study conducted in South Africa in 2018, the percentage of patients in the rst line of treatment with virological failure was 22% (19) .…”

Point-of-Care HIV Viral Load Testing: an Essential Tool for a Sustainable Global HIV/AIDS Response

“…A variety of studies conducted in high-and low-income settings have compared the diagnostic accuracy of the Xpert HIV-1 viral load assay to those of conventional laboratory assays, including the Abbott RealTime HIV-1 m2000rt (Abbott Molecular) (35)(36)(37)(38)(39)(40), Roche COBAS AmpliPrep/COBAS TaqMan (Roche Diagnostics) (41-44), Nu-cliSENS EasyQ HIV-1 v2.0 (bioMérieux) (45), and Versant HIV-1 RNA 1.5 assay (Siemens HealthCare Diagnostics) (46). In a recent meta-analysis of these studies, the pooled Pearson coefficient was 0.94 (95% CI, 0.89 to 0.97; n ϭ 8 studies) and the pooled Spearman coefficient was 0.96 (95% CI, 0.86 to 0.99; n ϭ 3), demonstrating good correlation with laboratory reference results (50). The Xpert HIV-1 had a mean bias of within 0.35 log copy/ml of the reference viral load assays.…”

Multicenter evaluation of Xpert HIV‐1 viral load assay for HIV quantification in China

“…Similar to our results, high correlation coefficients were also found by other studies between Xpert HIV‐1 VL and reference assays. In a systematic review on the performance of the Xpert HIV‐1 VL assay, a pooled Pearson coefficient was 0.94 and Spearman correlation was 0.96 14 . Apart from the Abbott RealTime HIV‐1 assay (Abbott Molecular), other reference assays has been used for the evaluation of Xpert HIV‐1 VL assay: Roche COBAS AmpliPrep/COBAS TaqMan HIV‐1 assay, NucliSENS EasyQ HIV‐1 assay, and Versant HIV‐1 RNA 1.5 assay 17,18 .…”