Final HIV Research Highlights From CROI 2018

Our coverage from the 2018 Conference on Retroviruses and Opportunistic Infections (CROI) in Boston wrapped up yesterday with two interviews with Federal HIV leaders who shared perspectives about the science coming out of the conference and its implications for HIV prevention, care, and treatment.

NIH's Dr. Carl Dieffenbach Discussed Drug-Drug Interactions, Organ Transplants, and Between PWLH

We heard from Dr. Carl Dieffenbach, Director of the Division of AIDS at NIH's National Institute of Allergy and Infectious Diseases (NIAID), and his colleague Anne Rancourt about some of the key research findings presented that day, including:

• Drug-drug interactions between contraceptive rings and antiretrovirals (ARVs) -- A study presented at CROI found drug-drug interactions between contraceptive hormones delivered by a vaginal ring and the drug efavirenz, an ARV commonly used in HIV treatment. These results are from a pharmacology study, meaning subjects took the drug and researchers took careful measurements of drug levels in the blood stream. Researchers found that efavirenz caused an 80% decrease in the level of the active contraceptive in the blood stream of women living with HIV. Read the study abstract and view the presentation. Carl and Anne also discussed the importance of studies of drug-drug interactions given that people living with HIV are often on other medications. So such studies examine whether different commonly used drugs interact with HIV treatment by changing the levels of the ARV or other drug in ways that could inhibit effectiveness or cause safety problems. Dr. Dieffenbach also noted that NIH is funding investigations to test a two-in-one product for HIV-negative women that can deliver both HIV prevention and contraception. Examining potential drug-drug interactions are an important part of these early phase studies for multi-purpose prevention technologies.

• Organ transplants from donors with HIV or HCV -- Another presentation at CROI reviewed encouraging results of organ transplants from HIV-positive donors to HIV-positive recipients, which is now allowed under research conditions as a result of the 2013 HIV Organ Policy Equity (HOPE) Act. Dr. Dieffenbach observed that end-stage liver and kidney disease are slightly more prevalent among people living with HIV than among the population as a whole and that waiting lists for donated organs are much larger than the available organs. According to the CROI presentation by Dr. Christine Durand of Johns Hopkins University, there are now 24 transplant centers across the U.S. with active HOPE Act research protocols; all are comparing outcomes among those with HIV-positive and HIV-negative donor organs. Across the country, 286 patients living with HIV have consented to receive an HIV-positive donor organ, and there have been 77 transplants from 22 donors. Dr. Durand also shared findings from an initial study at Hopkins of the use of organs from hepatitis C virus-infected donors for HCV-uninfected transplant candidates. In that study, the transplant team used the direct-acting antiviral agents used to treat HCV as both pre- and post-transplant prophylaxis to prevent infection in the organ recipient. At one year post-transplant, all 10 patients who underwent this process remain HCV-free. Both studies suggest innovative strategies that may be used to expand the organ donor pool. Read the presentation abstract, watch the presentation video on the CROI website.

• No evidence of ongoing HIV replication in lymph nodes during suppressive ART -- Dr. Dieffenbach also drew our attention to a study by Dr. Mary Kearney of NIH's National Cancer Institute. He explained that this is an important study because while individuals on ART are tested for detectable virus in their blood, there had been some lingering questions about whether the virus could be continuing to replicate at low levels elsewhere in the body (i.e., not in the blood). Dr. Kearney's team looked into the lymph nodes of many virally suppressed people living with HIV and found no evidence of ongoing replication. Read the study abstract or view the presentation. Among the reasons that this study is important, Dr. Dieffenbach observed, is that this data adds even more support to the understanding that someone living with HIV who is on ART and has achieved and sustains a suppressed viral load has effectively no risk of transmitting HIV to an HIV-negative partner. In the community, he observed, this is known as "undetectable equals untransmittable" or "U=U."

CDC's Dr. Jonathan Mermin Discusses HIV and Syphilis Infections Among MSM

New CDC data reported at CROI show that two intersecting public health threats -- HIV and syphilis -- are putting at risk the health of gay, bisexual, and other men who have sex with men across the United States. Dr. Jonathan Mermin, Director of CDC's National Center for HIV, Viral Hepatitis, STD, and TB Prevention, explained that men who have sex with men are disproportionately impacted by syphilis (accounting for the majority of reported cases nationally) and that STIs like syphilis increase the risk of acquiring HIV. Further, CDC estimates that men who have sex with men living with HIV are eight times more likely to be diagnosed with syphilis than those who are HIV negative (1,203 vs. 155 per 100,000 MSM). Dr. Mermin noted that there is an estimated two- to five-fold increased risk of acquiring HIV when syphilis is present -- because syphilis symptoms (sores) make it easier to acquire and transmit HIV. The troubling reality is that if you are an HIV-negative gay man who is diagnosed with primary and secondary syphilis, you are more likely to be infected with HIV in the future. But, Dr. Mermin advised, screening is a key first step to controlling syphilis. Once diagnosed, syphilis can be treated and cured with antibiotics. Read the abstract and view the poster [PDF, 838KB] that presents state-specific rates of primary and secondary syphilis among MSM living with diagnosed HIV and rates among MSM who are either HIV-negative or who do not know their HIV status.

[Note from TheBodyPRO: This article was originally published by HIV.gov on March 9, 2018. We have cross-posted it with their permission.]