AT CROI 2016
BOSTON (FRONTLINE MEDICAL NEWS) – Although antiretroviral therapy (ART) has been shown to reduce risk of HIV transmission, particularly among heterosexuals, there is a gap between patient perception of infectiousness and actual risk of HIV transmission, suggesting that clinicians need to do better at discussing implications with patients on treatment.
Among patients participating in a randomized clinical trial comparing three ART regimens, nearly half reported a decline in their perception of their own infectiousness (POI) at 48 weeks compared with study entry, but few participants thought themselves to be noninfectious at any time point, reported Dr. Raphael Landovitz of the David Geffen School of Medicine at the University of California, Los Angeles.
“We think this highlights some important opportunities for finding populations who need more education about what it means for their sexual partners in terms of their infectiousness by a sexual route as they achieve therapy, and I think as providers we can do a better job about contextualizing the benefits of antiretroviral therapy, not only for individuals, but for populations,” he said at a media briefing following his presentation of the data in an oral abstract session at the Conference on Retroviruses and Opportunistic Infections.
Dr. Landovitz and colleagues conducted a secondary analysis of data from the AIDS Clinical Trials Group (ACTG) A5257 Trial, which compared tenofovir/emtricitabine in combination with either atazanavir, raltegravir, or darunavir.
Patients in the trial were asked at baseline and every 48 weeks to rate on a visual analog scale from 0 to 100 their response to the question, “How likely would you be to give someone HIV if you had unprotected sex with them today?” – with 0 being not at all infectious, and 100 being highly infectious.
At baseline, 6% had a POI of not at all infectious, 10% thought themselves to be at low risk for HIV transmission. 26% considered themselves at medium risk, and 58% had a POI of highly infectious.
At week 48, 10% rated themselves as not infectious, 32% as low risk, 20% as medium risk, and 38% as highly at risk of transmission from unprotected sex.
These POI scores were at odds with the actual risk of infectiousness, however: At week 48, 91% of participants had HIV RNA levels of less than 50 copies per mL, the investigators found.
In multivariate analysis controlling for sociodemographic factors, sexual partner preferences and any stimulant drug use, factors associated with a greater probability of decline in POI included higher baseline POI, younger age, and higher level of education. In contrast, non-Hispanic blacks and patients with CD4 levels lower than 50 cells at the start of ART were less likely to have a decline in POI.
In all, 99 patients had a decline to a POI of not infectious. Factors associated with this change were baseline POI, female sex, and no stimulant drug use. Of those who thought of themselves as not infectious at week 48, 8 had HIV RNA levels about 50 copies/mL.
Interestingly, actual viral suppression was not associated with POI, Dr. Landovitz said.
In the briefing, he said that it’s incumbent on caregivers not to present patients with either/or choices, but instead to have a nuanced discussion about relative transmission risks. For example, if the patient has undetectable viral levels and is on treatment, is tested and treated for other sexually transmitted infections and has a known sexual dynamic, he or she probably has a very low risk of transmitting HIV to his/her sexual partner, he said.
However, “the challenge lies in messaging to patients that there are a lot of assumptions in that statement. What if the HIV-infected person has not been consistent with [his or her] antiretroviral therapy for whatever reason? … What if there’s been something traumatic going on in their lives, or what if there has been a new substance abuse overlay that’s compromised their ability to adhere, and they’re no longer virologically suppressed as they thought they were at their last measurement? Then that’s not a guarantee [of low risk],” he said.
“I try and couch it to patients that based on what we know, if someone really is on treatment and undetectable, the risk of sexual transmission is very low. It’s probably not zero, but it’s very, very low,” he added.
Primary funding for ACGT A5257 came from the National Institute of Allergy and Infectious Diseases. Dr. Landovitz disclosed receiving research grants to his institution and consulting fees from Gilead Sciences.