Initiating antiretroviral therapy (ART) earlier in the course of HIV infection is linked to better long-term health outcomes compared with delaying ART, according to findings presented at IDWeek Week in Washington, DC.
This finding is based on an extended follow-up of participants in the international Strategic Timing of Antiretroviral Treatment (START) study, funded by the National Institutes of Health (NIH). The initial START study’s findings were reported in 2015, and the current analysis compared primary study end points with those in the extended follow-up period between January 1, 2016, and December 31, 2021.
CD4+ T-cell counts are a key indicator of immune system health. The 2015 results showed participants who began ART when their CD4+ T-cell counts were greater than 500 cells/mm³ had a 57% reduced risk of AIDS and serious non-AIDS health outcomes compared with those who did not initiate ART until either their CD4+ counts dropped below 350 cells/mm³ or they developed AIDS.
Patients who were in the deferred arm of this study were advised to begin ART after results were published.
At the time of ART initiation, the median CD4+ cell count was 648 cells/mm³ for the immediate treatment arm and 460 cells/mm³ for the deferred arm.
The initial study included 4685 total participants, and the extended follow-up included 4446 participants. Although the initial study demonstrated a clear benefit to early ART initiation, the researchers wanted to investigate further if these benefits increased, remained constant, or declined after the participants in the deferred arm initiated ART.
In the follow-up, most participants from the deferred arm were receiving ART and experienced rapid and sustained declines in HIV viral load, defined as 200 copies/mL or fewer. However, CD4+ cell counts remained 155 cells/mm³ lower in this group compared with the cell counts of participants in the immediate ART group, on average.
“While the risk of serious health outcomes was substantially diminished soon after ART was initiated in the deferred treatment group, some excess risk remained compared with the immediate treatment group,” the NIH report of the study said.
The extended follow-up also found the deferred ART group continued to have a 21% greater risk of serious negative health outcomes or mortality compared with the immediate ART group.
During the 5-year period, researchers saw 27 cases of AIDS in the deferred arm and 15 in the early treatment arm. They also recorded 88 cases of serious non-AIDS health issues and 57 deaths in the deferred treatment arm and 76 cases and 47 deaths in the immediate treatment arm.
According to the presenters, these findings confirm that ART can significantly improve an individual with HIV-related health and reduce their risk of developing AIDs and other serious health issues. They also support the idea that early HIV diagnosis and treatment are crucial to maximizing benefits and reducing risk.