This Week in HIV Research: Predicting Long-Term Undetectable Viral Loads; and Spontaneous Controllers of HIV
This week, a study finds that people with HIV who achieve an undetectable viral load with their first regimen may never experience viral rebound. Another study finds that spontaneous controllers of HIV are more likely to be African Americans or women. And a modeling study suggests that the U.S. can still achieve the United Nation's 90-90-90 goals by 2020. To beat HIV, you have to follow the science!
Initial Viral Suppression Predicts Long-Term Undetectable Viral Load
People living with HIV who achieve viral suppression on their first antiretroviral treatment regimen may well never experience viral rebound, an analysis of data from the UK CHIC study published in The Lancet HIV showed.
Viral suppression was defined as a viral load of < 50 cells/mL, and rebound as at least one measurement of > 200 cells/mL. The overall rate of first viral rebound was 7.8 per 100 person years, but almost 30% of these were temporary viral "blips." Researchers calculated the likelihood of durable detectable viral load for various scenarios, arriving, for example, at a 1% chance for men who have sex with men and are at least 45 years old.
Longer duration of undetectable viral load, older age, more recent treatment start, and antiretroviral initiation at lower viral loads were all associated with a reduced risk of viral rebound. Conversely, sub-Saharan African origin slightly increased that risk. Study authors hypothesized that this may be related to socioeconomic conditions in that group.
Majority of Spontaneous Controllers of HIV Are Women or African Americans
African Americans and women are more likely to control their HIV without antiretroviral treatment than are other demographic groups, a review of medical records published in AIDS found.
Researchers reviewed the records of more than 45,000 people living with HIV in the greater Los Angeles and Miami areas. They analyzed close to 30,000 of these for people whose viral load was below 50 RNA copies/mL for at least one year without treatment. Only 53 people fit that description. Almost half of these viral controllers were women and over 60% were African American. This corresponded to 0.58% of all women and 0.33% of all African Americans in the cohort, compared to 0.18% among all 30,000.
The frequency of viral "blips" predicted whether these spontaneous controllers' HIV durably returned to detectable levels. Results suggest that controlling HIV without antiretrovirals is "an extreme along a continuum of HIV-1 infection" and not qualitatively different from having undetectable virus while on treatment, study authors concluded.
U.N. 90-90-90 Goals Achievable in the U.S.
The U.S. can achieve the United Nation's 90-90-90 goals by 2020, a mathematical modeling study published in American Journal of Preventive Medicine showed.
These goals stipulate that 90% of people living with HIV know their serostatus, 90% of those living with HIV are on treatment, and the virus of 90% of those on treatment is below detectable levels. For 2030, these targets are 95-95-95. In the U.S., this translates into a maximum of 21,000 annual seroconversions by 2020 and no more than 12,000 per year by 2025.
Study authors noted that the first two of the 2020 goals have already been met in New York City, and the third goal has been achieved among white people in that city. However, to reach these targets nationally, "pernicious health disparities" among regions, races/ethnicities, and sexual orientations must be eliminated, they added. Authors called for real-time epidemiologic tracking and expanded implementation research to help guide the allocation of resources for HIV prevention and treatment.
Extracellular Vesicles Help Spread HIV in Body
A protein that facilitates the spread of HIV in a person is also carried by extracellular vesicles (EVs) that are released by HIV-infected cells, a study published in Scientific Reports found.
The protein, gp120, was previously thought to be carried by virions. Researchers devised a new method for separating EVs from other material by using magnetic forces. They then tested HIV preparations with and without EVs on human tissue in vitro and found a 50% reduction in infection when EVs were not present. Further experiments showed that EVs carrying gp120, in particular, facilitated the spread of HIV among cells.
"If we remove extracellular vesicles from HIV laboratory preparations, we also reduce HIV infection of human tissues in culture," study author Leonid Margolis, Ph.D., of the National Institutes of Health explained in a related press release. New anti-viral strategies could target these EVs to intercept the transfer of viral material to new cells, study authors concluded.