Antiretroviral treatment of HIV-1 in Sweden with focus on virological aspects

Abstract

From a clinical standpoint, there are many factors to consider when optimizing the care for people living with HIV (PLWH). With help from clinical guidelines, most obstacles can be addressed. Expanded knowledge is however in constant demand, from local conditions to universal processes. This thesis emerged from a demand for both clinical and virological data about the effect of antiretroviral treatment (ART) in Sweden. All data were derived from the national InfCareHIV database. The current goal of ART is to achieve lasting suppression to < 50 HIV RNA copies/mL. Transient episodes of viremia up to 500 copies/mL, so-called viral blips, are not uncommon. We sought to investigate the clinical importance and outcome of this phenomenon. Through two large retrospective studies, Paper I and IV, we concluded that it is more common with blips in PLWH with higher baseline viral load and ART based on boosted Protease Inhibitors (PI). Blip incidence during Integrase Strand Transfer Inhibitors (INSTI) and Non- Nucleoside Reverse Transcriptase Inhibitor-based ART was lower at a similar level. In PLWH who reached HIV RNA suppression after initiating their first ART, blips were relatively common (10–20% of all participants) but not associated with an increased risk of virological failure. Before the introduction of the INSTI dolutegravir, PLWH with resistance mutations to Nucleoside Reverse Transcriptase Inhibitors were often restricted to PI-based treatment. PIs are characterized by many drug interactions and often tolerability issues. In Paper II, 244 participants with either dolutegravir or traditional PI-based ART were retrospectively studied. Dolutegravir has pharmacological benefits and we concluded that it was an equivalent alternative. Treatment recommendations are not affected by different levels of baseline viremia. Most clinical studies compare the outcome in participants with higher or lower than 100,000 HIV RNA copies/mL. Considerably higher levels of viremia are sometimes observed. In Paper III, we included 2,956 PLWH of whom 394 (13%) had baseline > 500k HIV RNA copies/mL. We found that participants with that high initial viremia needed longer time to reach viral suppression. Initial treatment with INSTIs was associated with faster viral decline. Higher baseline viral load was not associated with an increased risk of virological failure.