Immunological and virological response to initial antiretroviral therapy among older people living with HIV in the Canadian Observational Cohort (CANOC).

OBJECTIVES: The aim of this study was to assess the adequacy of immunological recovery and virological suppression in response to antiretroviral therapy (ART) in the growing population of older people living with HIV (PLWH), as treatment regimens become more effective and tolerable. METHODS: An interprovincial Canadian cohort of treatment-naïve PLWH who initiated ART after 1 January 2000 was used and age assessed in decades. Longitudinal absolute CD4 count response to treatment was modelled using generalized estimating equations. Cumulative incidence functions and proportional hazards models with a competing risk of death were used to estimate time to: (1) CD4 ≥ 200 cells/µL, (2) CD4 ≥ 500 cells/µL, (3) virological suppression (≤ 50 copies/mL), and (4) virological failure (> 200 copies/mL). RESULTS: In all, 12 489 individuals starting ART between 2000 and 2016 with one or more post-treatment CD4 count or viral load were included in the analysis. Age > 60 years was associated with lower absolute CD4 recovery (adjusted ß = -31 cells/µL) compared with age ≤ 30 years when pre-treatment CD4 count and other covariates were accounted for. Older age groups were less likely to achieve a CD4 ≥ 500 cells/µL, with the greatest effect in the > 60 group [adjusted hazard ratio (aHR) = 0.69, 95% confidence interval (CI): 0.57-0.84 vs. age ≤ 30). Older age groups were more likely to achieve viral suppression (age > 60, aHR = 1.20, 95% CI: 1.05-1.37) and less likely to have virological failure (age > 60, aHR = 0.46, 95% CI: 0.3-0.71) compared with those aged ≤ 30 years. CONCLUSIONS: Older adults have robust virological responses to ART; however, individuals over the age 60 are more likely to experience blunted CD4 recovery.

Non-nucleoside reverse transcriptase inhibitor failure impairs HIV-RNA responses to efavirenz-containing salvage antiretroviral therapy.

In a retrospective cohort study of salvage antiretroviral combination therapy including efavirenz, 60% of 51 patients were able to suppress HIV RNA by at least 1 log10 or to less than 50 copies/ml. A lack of the previous use of non-nucleoside reverse transcriptase inhibitors was the only factor predictive of response on multivariate analysis. No patient with a viral isolate with an increased IC50 to efavirenz by virtual phenotype had a virological response