Benefits of INSTI-Based Regimens in a Real-World Setting of People Living With HIV-1 in Colombia.

Objective: The objective is to compare the clinical, virological, and immunological characteristics of people living with HIV-1 who were treated with first-line integrase inhibitors (INSTIs) versus those treated with other antiretrovirals. Methods: This is a descriptive observational, retrospective, two-center study. We selected individuals who began antiretroviral therapy (ART) within the first year of diagnosis and who had received at least 1 year of treatment. Their therapy consisted of two nucleoside/nucleotide reverse transcriptase inhibitors, along with a third medication (INSTI, nonnucleoside reverse transcriptase inhibitor (NNRTI), or protease inhibitor). The primary comparison was between individuals who initiated ART containing INSTIs and those who initiated ART containing NNRTIs or protease inhibitors. We evaluated clinical outcomes, residual viral load, circulating proviral DNA, inflammation, and cardiovascular risk markers, T cell count and phenotype, and the frequency of HIV-specific T cells. Results: Individuals who received INSTI-based regimens started treatment at a more advanced disease stage and had a significantly shorter ART duration at study inclusion than individuals who did not receive INSTI-based ART. Individuals receiving INSTIs achieved CD4⁺ T cell counts at levels comparable to those within the non-INSTI group, as well as similar levels of virological, immunological, and cardiovascular markers. Nonetheless, those in the INSTI-based group had higher CD8⁺ T cell counts and lower CD4/CD8 ratios, as well as lower high-density lipoprotein levels. Conclusions: INSTI-based regimens offer benefits to Colombian people living with HIV-1, who are starting ART, including improved and faster virological and CD4⁺ T cell reconstitution. This occurs despite treatment initiation for advanced disease.