Starting antiretroviral treatment (ART) early in the course of HIV infection when the immune system is strongest results in better long-term health outcomes compared with delaying ART, according to findings presented today at the IDWeek Conference in Washington, D.C.
The findings are based on long-term follow-up of participants in the Strategic Timing of Antiretroviral Therapy (START) study funded by the National Institutes of Health. In 2015, START demonstrated a 57% reduction in the risk of AIDS and serious non-AIDS health outcomes among participants who began ART when their CD4+ T-cell counts, a key indicator of immune system health, decreased. they were greater than 500 cells per cubic millimeter. (mm³) compared to those who did not start ART until their CD4+ counts fell below 350 cells/mm³ or they developed AIDS. Following the 2015 reporting of these findings, participants in the deferred treatment arm were advised to start ART.
Approximately 1.2 million people in the United States are living with HIV and about 13% do not know they are infected, according to the Centers for Disease Control and Prevention. When HIV diagnosis and treatment are delayed, HIV continues to replicate. This can have a negative impact on the health of the infected person and increase the risk of transmitting the virus to other people.
The international START study demonstrated benefit from early initiation of ART, but longer-term follow-up of 4,446 participants was conducted to determine whether the health benefits of early ART compared with delayed ART increased, remained constant, or decreased after ART initiation. than participants in deferred ART. they were advised to start ART. The study’s primary endpoints included the number of participants who developed AIDS; those who developed serious health conditions not related to AIDS, such as major cardiovascular disease, kidney failure, liver disease, and cancer; and those who died.
For participants who started ART before the end of 2015, the median CD4+ cell count at the time of ART initiation was 648 cells/mm³ for the immediate arm and 460 cells/mm³ for the delayed arm. The analysis presented today compared the study’s primary endpoints before the end of 2015, with those in the extended follow-up period, from January 1, 2016, to December 31, 2021. In the latter period, most participants in the deferred arm were taking ART. During the second period, people who started ART in the deferred group had rapid and sustained declines in HIV viral load (less than or equal to 200 copies/mL); however, CD4+ cell counts remained, on average, 155 cells lower compared to those of people in the immediate ART group. Although the risk of serious health outcomes was substantially reduced shortly after ART was started in the deferred treatment group, an excess risk remained compared with the immediate treatment group. The delayed ART group continued to have a slightly higher risk (21%) of serious health consequences or death compared to the immediate treatment group. Twenty-seven cases of AIDS occurred in the five-year follow-up period in the delayed treatment group compared to 15 cases in the early treatment group. Similarly, 88 cases of serious non-AIDS-related health problems occurred in the delayed treatment arm compared with 76 cases in the immediate treatment arm. Lastly, there were 57 deaths in the delayed treatment group compared to 47 in the immediate treatment arm.
These findings confirm that ART significantly improves the health of a person with HIV and reduces the person’s risk of developing AIDS and serious health problems, and that early diagnosis and treatment are key to maximizing these benefits and reducing risk. according to the presenters.
The START study and its extended follow-up was conducted by the International Network for Strategic Initiatives in Global HIV Trials (INSIGHT), funded in part by the National Institute of Allergy and Infectious Diseases (NIAID), part of the NIH. It was led by principal investigator James D. Neaton, Ph.D., of the University of Minnesota, Minneapolis, and START study co-chairs Abdel Babiker, Ph.D., of University College London, and Jens Lundgren, MD, from the University of Copenhagen.