Hybrid next-generation sequencing protocol for testing HIV-2 drug resistance

HIV-2 affects over 1 million people globally and can lead to AIDS if untreated. Treating people living with HIV-2 (PLHIV-2) is challenging because the virus is inherently resistant to some drugs. Effective treatment monitoring, particularly drug resistance testing, is critical for managing therapeutic failure. Without commercial tests to identify drug resistance mutations (DRM), laboratories have felt the need to develop in-house methods. NGS provides improved sensitivity for detecting minority DRM, which is crucial for effectively treating individuals, especially with limited therapeutic options. This study aimed to evaluate the effectiveness of a hybrid NGS Ion Torrent protocol for the detection of DRM in PLHIV-2 and its use in clinical practice. One hundred samples from PLHIV-2 collected from hospitals across Portugal were analyzed using a hybrid NGS protocol. Of these, 48 samples were also subjected to Sanger sequencing for comparative purposes. NGS successfully amplified 92 % of protease, 91 % of reverse transcriptase, and 49 % of integrase regions. The two sequencing methods agreed on the majority of DRM identified, with the only difference in two samples for the reverse transcriptase, which NGS identified as K70E and M184V, while Sanger did not. Hybrid NGS was able to identify DRM, demonstrating strong statistical agreement. In conclusion, hybrid NGS detected all DRM identified by Sanger, with the added ability to detect minority variants. The implementation of NGS-based protocol can provide clinicians with more comprehensive data, allowing for adjustments to ART regimens, and ultimately improving patient outcomes and quality of care for PLHIV-2.