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Current HIV Research

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ISSN (Print): 1570-162X
ISSN (Online): 1873-4251

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Research Article

Can In-house HIV-2 Viral Load Assay be a Reliable Alternative to Commercial Assays for Clinical and Therapeutic Monitoring?

Author(s): Veena Vadhini Ramalingam, Gnanadurai John Fletcher, Anand Kasirajan, John Paul Demosthenes, Priscilla Rupali, George Mannil Varghese, Susanne Alexander Pulimood, Grace Rebekah and Rajesh Kannangai*

Volume 20, Issue 4, 2022

Published on: 02 September, 2022

Page: [274 - 286] Pages: 13

DOI: 10.2174/1570162X20666220609155237

Price: $65

Abstract

Background: Currently, there is a global contemplation to end the AIDS epidemic by 2030. HIV-2 poses unique challenges to this end. The burden of HIV-2 is higher in resource-limited countries, and it is intrinsically resistant to NNRTI drugs. In addition, there is no FDA-approved plasma viral load assay to monitor disease progression and therapeutic efficacy. To overcome these challenges, we have developed and evaluated an in-house quantitative HIV-2 viral load assay.

Methods: Blood samples were collected from 28 HIV-2 treatment-naïve monoinfected individuals and tested using an in-house qPCR HIV-2 viral load assay. The extracted RNA was amplified using Quantifast pathogen + IC kit.

Results: The in-house qPCR has a limit of detection of 695 copies/ml. The intra- and inter-assay variation (% CV) of the assay was 0.61 and 0.95, respectively. The in-house assay quantified HIV-2 NIBSC accurately (1000 IU) with a mean of 1952 copies/mL. Among the 28 samples tested by in-house qPCR assay, 11 (39.2%) samples were quantified, whereas 17 (60.7%) samples were not detected. In comparison with Altona RealStar HIV-2 RT PCR and Exavir Load RT assay, the results were 96.4% and 69.6% concordant, respectively. No significant (p = 0.99 and p = 0.13) difference in quantifying viral load between the three assays. Based on clinical and immunological (CD4) staging, the performance characteristics were comparable.

Conclusion: To the best of our knowledge, this is the first in-house qPCR developed in India. The performance characteristics of the in-house assay are comparable to the commercial assays, and they can be used assertively to monitor HIV-2 patients.

Keywords: HIV-1, HIV-2, quantitative real-time polymerase chain reaction, viral load, NNRTI, simian immunodeficiency virus (SIV).

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