This Week in HIV Research: The PrEP Sex/Race Gap
This week, our tour of recently published research of note in the HIV universe takes us past the following new landmarks:
- A huge gap between pre-exposure prophylaxis (PrEP) being indicated and PrEP being taken in the U.S. -- that is, among anyone who isn't a white male.
- An array of differences in antiretroviral therapy usage and viral suppression rates across HIV transmission categories in Europe.
- An examination of the effect that modern-era hepatitis C (HCV) treatments have had on mortality among people coinfected with HIV and HCV.
- An analysis highlighting sex-based differences in cognitive impairment among people with HIV -- particularly African Americans.
Let's take a few minutes to explore each of these studies a little more deeply. To beat HIV, you have to follow the science!
Barbara Jungwirth is a freelance writer and translator based in New York. Follow Barbara on Twitter: @reliabletran.
Myles Helfand is the executive editor and general manager of TheBody and TheBodyPRO. Follow Myles on Twitter: @MylesatTheBody.
Many People of Color and Women Who Should Get PrEP Don't Get It
Women, African Americans, and Latinx people took pre-exposure prophylaxis (PrEP) at significantly lower rates than their proportions among the 1.1 million adults for whom biomedical prevention is indicated, a study published in Morbidity and Mortality Weekly Report found.
Researchers analyzed prescriptions for tenofovir disoproxil fumarate (Truvada) without other HIV medications in a nationwide database, yielding 78,360 PrEP users. The U.S. Centers for Disease Control and Prevention (CDC) estimates that 43.7% of those who need PrEP are African American and 24.7% are Latinx.
Study authors cautioned that race/ethnicity data were available only for 42% of participants; among these, 11.2% were African American and 13.1% were Latinx, pointing to a large gap between rates of PrEP indication and prescription. Among women, the disparity was even greater -- 2.1% of heterosexual women who might benefit from biomedical prevention filled prescriptions for Truvada.
Study authors called for research on barriers to PrEP use among these groups and public health efforts to increase its uptake among people who are not white men.
Antiretroviral Use, HIV Suppression Rates Vary Widely Across Europe
The likelihood that a person with HIV living in Europe will be on antiretroviral therapy or have a suppressed viral load may depend on their transmission category and/or their geographical location, a study published in AIDS showed. The study focused on people who fall within one of three transmission categories: heterosexuals, men who have sex with men (MSM), and people who inject drugs (PWID).
In Western and Northern Europe, antiretroviral use was more common among those who had acquired HIV through heterosexual contact than among MSM or PWID. Conversely, in Eastern Europe, more MSM than the other two categories received antiretrovirals. Across the continent, PWID were least likely to be on antiretroviral therapy or to be virologically suppressed compared to the other two groups.
Study authors cautioned that because of restrictive policies in some countries regarding MSM and PID, people within these communities may have been misclassified. In addition, all 12,872 participants were in HIV care at specific clinics; this may have undercounted some key populations by excluding people in prison and migrants.
Still, results point to the need for disaggregated data to develop targeted interventions for key populations that may differ by region, study authors concluded.
Newer Treatments Almost Negate HCV-Related Mortality Risk Among Coinfected People
In people living with HIV (PLWH), hepatitis C (HCV) coinfection increased the 10-year mortality risk by 4.3%, an estimate published in Clinical Infectious Diseases showed. However, that risk appeared to be largely offset by newer HCV medications called direct-acting antivirals (DAA): The study found that DAA reduced 10-year mortality among people with HIV/HCV coinfection by 3.8% compared to people who did not receive DAA. This difference is likely due to residual liver fibrosis after HCV has been cured, study authors suggested.
Previous studies of people taking older HCV treatment regimens based on pegylated interferon (PEG-IFN) estimated a greater drug effect on mortality. However, these medications had severe side effects, which meant that only some could tolerate them, which in turn introduced unmeasured cofounders.
The authors of the current study noted that 58% of participants were women, compared to 23% among all PLWH in the U.S. This may limit the generalizability of the results. Furthermore, the estimates rest on assumptions that may be inaccurate, including assumptions regarding DAA efficacy and side effects. Nonetheless, the study shows that greater efforts to address coinfection are needed and that insurers should expand access to DAA, study authors concluded.
Sex Differences in Cognitive Impairment Are Attenuated by Reading Level
Women living with HIV are at greater risk for experiencing neurocognitive impairment (NCI) than men, an observational cohort study published in AIDS found. African-American women appeared to be particularly at risk, but the difference between African-American women and men disappeared when reading levels -- a proxy for cognitive reserves -- were considered.
Researchers analyzed data on 2,063 participants (20% women), 1,361 of whom were living with HIV. Among the HIV-positive population, a much higher proportion of women than men were African American. Some of the observed neurocognitive differences may be explained by lower reading levels among the women in the study compared to men, study authors reasoned. They advised HIV clinicians to be aware of African-American women's greater risk for NCI.
A previous study that included equal numbers of women and men also found worse cognitive scores among women. Its authors attributed the result to psychological factors, or possible sex differences in pharmacokinetics, as well as the effects of menopause.