Prevalence of drug resistance mutations in HIV-infected individuals with low-level viraemia under combination antiretroviral therapy: an observational study in a tertiary hospital in Northern Taiwan, 2017–19

Abstract

Abstract Background Effective ART is crucial for combating the HIV pandemic. Clinically, plasma viral load monitoring to achieve virological suppression is the guide for an optimal ART. The presence of low-level viraemia (LLV) below the definition level of virological failure is a risk factor for ART failure. However, there is no treatment consensus over LLV yet, mainly due to the limitation of standard HIV-RNA genotyping and the resultant insufficient understanding of LLV characteristics. Objectives To better profile drug resistance mutations (DRMs) and the associated factors in cases experiencing LLV. Methods A prospective observational study was conducted from 2017 to 2019. HIV-DNA was used as an alternative to HIV-RNA for HIV genotyping coupled with deep sequencing for ART-naive and ART-failure cases, as well as those with LLV. Results Eighty-one ART-naive, 18 ART-failure and 16 LLV cases received HIV genotyping in the study. Three-quarters (12/16) of cases experiencing LLV harboured DRMs. Cases with LLV had higher prevalence of DRMs to NNRTIs than the ART-naive group (69% versus 20%, P < 0.001), but lower DRM prevalence to NRTIs than the ART-failure group (25% versus 61%, P < 0.001). Approximately half of the LLV cases had issues of suboptimal ART compliance/ART interruption, and 68.8% (11/16) did not display drug resistance to their ART at the time of LLV. Conclusions HIV DRM profiles in LLV cases were significantly different to those in ART-naive and ART-failure cases. Approaches to consolidate ART compliance and early exploration of potential ART resistance may be needed for cases experiencing LLV episodes.