The effect of protease inhibitor-based dual antiretroviral regimens on CD4/CD8 ratio during the first year of therapy in ART-naïve patients with HIV-infection.

OBJECTIVES: To assess the effect of protease inhibitor (PI)-based dual therapy on CD4/CD8 ratio during the first year of therapy in antiretroviral therapy (ART)-naïve patients using data from randomized controlled clinical trials. METHODS: We pooled data from the GARDEL and ANDES studies, both randomized controlled clinical trials that recruited ART-naïve people living with HIV and randomly assigned them to receive PI-based dual therapy (DT) or triple therapy (TT) aiming to compare viral efficacy. We compared median CD4/CD8 ratios and the proportion of patients with CD4/CD8 ratio > 1 at 48 weeks after ART initiation in both treatment arms using the Mann-Whitney U-test and the χ2 test. We performed subgroup analysis for patients > 50 years old, with baseline CD4 counts ≤ 200 cells/µL, viral load > 100 000 HIV RNA copies/mL, and ritonavir-boosted lopinavir-based therapy. RESULTS: We analysed data from 571 patients: 292 on DT and 279 on TT. No differences were observed in CD4/CD8 ratio (0.632 vs. 0.617, P = 0.729) or in the proportion of patients with CD4/CD8 ratio > 1 (17.9% vs. 19.3%, P = 0.678) 48 weeks after ART initiation. Subgroup analysis showed no further differences. CONCLUSION: The impact of PI-based DT regimens on the CD4/CD8 ratio during the first year of treatment for ART-naïve patients is similar to that of TT.

Dual therapy with raltegravir plus a fixed dose combination of darunavir/ritonavir in people living with HIV in Argentina.

OBJECTIVE: There are generic fixed-dose combinations (FDCs) of ritonavir-boosted darunavir (DRV/r) available in Argentina. Experiences with these FDCs in dual therapy remain limited in clinical practice. We aimed to describe clinical and virologic outcomes in patients exposed to FDC DRV/r + raltegravir (RAL) 400 mg every 12 h in a real-life setting. METHODS: Retrospective analysis of electronic medical records of HIV-infected patients under FDC DRV/r + RAL in an HIV clinic in Argentina (2014-2018). Individuals were classified as "switch group" (SG, undetectable viral load [VL] with any toxicity/comorbidity) and "virologic group· (VG, detectable viremia and infection by multidrug-resistant HIV). RESULTS: Of 7,380 patients on ART, 116 (1.5%) received FDC DRV/r + RAL, being 58% in SG. Sixty percent received DRV/r 800/100 mg dose (rest, 600/100 mg). The median (IQR) age and CD4+ T-cell count were: 52 (42-58) years, and 373 cell/µL (202-642). Ninety-eight percent were ART-experienced with a median of 3 (IQR 2-5) prior treatments. Main reasons for switch (SG) were renal (57%), cardiovascular (54%) and bone (14%) comorbidities. Median exposure to DRV/r + RAL was 18 months. Among patients in SG, 98% and 96% had undetectable VL at 6 and 12 months; in the VG, 89% and 87% had undetectable VL at 6 and 12 months. No patient required suspension due to toxicity/ intolerance. CONCLUSIONS: In this cohort of mostly experienced HIV-infected patients, FDC DRV/r + RAL was effective and safe. Such therapy may be considered an option for patients with comorbid conditions and/or with multidrug-resistant HIV.

Resistance to HIV integrase strand transfer inhibitors in Argentina: first interim survey.

OBJECTIVE: No data on resistance to HIV integrase strand transfer inhibitors (InSTIs) in Argentina are available as access to these drugs and to integrase genotypic resistance test is limited. We aimed to evaluate the clinical profile of patients who underwent an integrase genotypic resistance test, prevalence of InSTI resistance mutations and predicted efficacy of raltegravir, elvitegravir and dolutegravir in our country. METHODS: Retrospective multicentric pilot survey from January 2011 to November 2017 of InSTI-failing patients assisted at two private and one public healthcare institutions located in Buenos Aires city, Argentina. RESULTS: Sixty seven patients were included. Patients had a median of 5 (4-7) prior treatments. All patients had InSTI-containing regimens (median exposure of 22.5 months); 94% were under raltegravir therapy and 71.9% had InSTI-resistance mutations. Predominant major mutations were N155H (35.1%), Q148H/R (15.8%) and G140A/S (14%). Considering Stanford HIVdb program, extremely low and identical activity of raltegravir and elvitegravir was described while dolutegravir remained either partially or fully active in 97.7% of patients. CONCLUSIONS: Integrase resistance test was prescribed almost exclusively in heavily pretrated raltegravir-exposed patients. The three main mutational pathways were described, with a predominance of N155H. Despite almost null susceptibility and extensive cross resistance was shown among raltegravir and elvitegravir, dolutegravir remains active in the majority of patients.