PrEP in the Transgender Population: New Study to Examine Effects

Infectious Disease Advisor: Are there any unique challenges when studying the transgender population?  How do you address them as part of your study?

Dr Morris: There are some important issues, and they are strongly related to the overall lower socioeconomic status of this population and their history of discrimination. Transgender individuals have experienced discrimination in every aspect of their lives, including within the medical community. Studies across the United States have indicated that transgender people experience obstacles when attempting to access adequate primary health care.  Often they are isolated from family, religious groups, and healthcare providers. To overcome this situation, transgender people have fostered their own support networks to obtain peer advice and share safe places to get medical care and other essential services. Unfortunately, many transgender people still have bad experiences in the medical setting and do not get treated appropriately. Therefore, there is an overall apprehension associated with becoming part of research.

At the same time, there are voices being raised within the transgender community demanding that resources in research be targeted at and for the transgender population.  It is very important to involve the community continuously and from the beginning in every research effort. For example, we organized several focus groups and individual interviews in our study to ensure that everything we propose is acceptable, both in terms of treatment and infrastructure. This is absolutely necessary because we are trying to gain the trust of this community, and it is very important to deliver a positive experience from the very beginning. To effectively engage transgender women, research programs need to use trans-inclusive strategies and ensure that services are delivered by providers who are knowledgeable in trans health issues.

Infectious Disease Advisor: What are the effects of hormonal therapy on HIV infection and immune response and treatment?

Dr Morris: We know that cisgender women have lower viral loads and higher CD4 T cells than men, which seems to be partially related to the estrogen effect.  There are also differences in terms of how HIV progresses based on the hormones that some people have in their body.  But these effects have not been studied in the setting of exogenous hormonal therapies used for sexual transition.

Infectious Disease Advisor: Are there specific hormonal therapy combinations that should be avoided because of their effects on certain antiretroviral therapies for HIV?

Dr Morris: This is a common concern within the transgender community. Not enough studies are available on the use of antiretroviral therapy (ART) in transgender women using feminizing hormones, and most data on drug-drug interactions are extrapolated from studies using combination oral contraceptives. It is important to note that HIV and its treatment are not contraindications to hormone therapy and based on available data, most ART can be used safely with estrogen (with few exceptions).6 With regard to PrEP, there is no evidence that tenofovir (or emtricitabine) affects levels of estrogen or progesterone products or vice versa. However, this has not been demonstrated in a transgender population, and it is one of the goals in our upcoming PrEP study. For providers interested in learning more about these issues, I suggest they check out the web page of the Center of Excellence of Transgender Health at UCSF.

Infectious Disease Advisor: When thinking about the HIV cure agenda, do you believe that the effects of hormonal therapy might influence the choice of cure strategy for the transgender population?

Dr Morris: That is a very good question, and more studies are needed to understand that fully.  Getting back to HIV pathogenesis, it is very likely that hormonal therapy might have real implications regarding cure studies. In fact, there is evidence that estrogens are strong inhibitors of HIV transcription, and we do not know if the same interventions to eradicate HIV will be effective in transgender women. In particular, agents that are designed for “kick-and-kill” strategies may be impacted by estradiol-mediated mechanisms and this needs to be evaluated as part of future studies.

Infectious Disease Advisor: Dr Morris, would you like to add anything in conclusion about future direction and how we should address this important issue?

Dr Morris: It is crucial to get everybody to be culturally competent as much as possible, and it is not just asking about a person’s pronouns.  Asking is important, but we also need to be – at a systemic level – facilitating that, and that people are being educated and systems are set up so that they can be receptive to the transgender population just like everybody else is into the system.  When we get to the research side, it is building that trust and following through on what you promised to do and keeping your word. Once we can develop that, there is a lot more work to be done.  Obviously, we need to know more about prevention and treatment, as well as learning how we can do a better job in clinical practice, and ultimately that is what we’re trying to inform so that outcomes are better.  That would be a huge thing to accomplish.

Click here to read part 2 of this series, in which Dr Gianella talks with Brooke Sullivan about her transition, living with HIV, her experiences with activism, barriers to HIV prevention and care for transgender people, and taking part in clinical trials to enhance understanding of HIV research within this group.

Sara Gianella Weibel, MD, is an assistant professor of medicine at the University of California, San Diego Center for AIDS Research.

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