Hortensia Álvarez (Infectious Diseases Unit, Department of Internal Medicine, University Hospital of Ferrol, A Coruña, Spain) et al. (175)

Abstract: Objectives: To pinpoint factors associated with low-level viraemia (LLV) and virological failure (VF) in people living with HIV in the era of high-efficacy antiretroviral treatment (ART) and widespread use of integrase strand transfer inhibitor (INSTIs)-based ART. Methods: We included adults aged > 18 years starting their first ART between 2015 and 2018 in the Spanish HIV/AIDS Research Network National Cohort (CoRIS). Low-level viraemia was defined as plasma viral load (pVL) of 50–199 copies/mL at weeks 48 and 72 and VF was defined as pVL ≥ 50 copies/mL at week 48 and pVL ≥ 200 copies/mL at week 72. Multivariable logistic regression models assessed the impact on LLV and VF of baseline CD4 T-cell count, CD4/CD8 T-cell ratio and pVL, initial ART classes, age at ART initiation, time between HIV diagnosis and ART initiation, gender and transmission route. Results: Out of 4186 participants, 3120 (76.0%) started INSTIs, 455 (11.1%) started boosted protease inhibitors (bPIs) and 443 (10.8%) started nonnucleoside reverse transcriptase inhibitors (NNRTIs), either of them with two nucleos(t)ide reverse transcriptase inhibitors (NRTIs). Low-level viraemia was met in 2.5% of participants and VF in 4.3%. There were no significant differences throughout the years for both virological outcomes. Baseline HIV-1 RNA > 5 log10 copies/mL was the only consistent predictor of higher risk of LLV [adjusted odds ratio (aOR) = 9.8, 95% confidence interval (CI): 2.0–48.3] and VF (aOR = 5.4, 95% CI: 1.9–15.1), even in participants treated with INSTIs. Conclusions: The rates of LLV and VF were low but remained steady throughout the years. Baseline HIV-1 RNA > 5 log10 copies/mL showed a persistent association with LLV and VF even in participants receiving INSTIs.