2 HIV Research Studies You Should Know This Week
A common birth control shot has been linked with increased risk of HIV infection while NIAID investigators have found that putting ART on pause during a clinical trial might not be as detrimental as first thought.
*Updated: 1/18/2017 at 10:00 AM EST
A common birth control shot has been linked with increased risk of HIV infection while NIAID investigators have found that putting ART on pause during a clinical trial might not be as detrimental as first thought.
DMPA Linked with Increased Risk of HIV Infection
A research review published in Endocrine Reviews, posited that there may be a potential association between HIV risk and use of the progestin-only 3-monthly injectable depo-medroxyprogesterone acetate (DMPA) birth control shot.
This increased susceptibility to sexually transmitted infections may be linked with the type of progestin used in DMPA, medroxprogesterone acetate (MPA). According to a press release on the research, “MPA acts differently than other forms of progestin used in contraceptives. MPA behaves like the stress hormone cortisol in the cells of the genital tract that can come in contact with HIV.” First author, Prof. Janet P. Hapgood, Ph.D., of the University of Cape Town in Cape Town, South Africa spoke about the significance of the review in the press release, stating, “Studying the biology of MPA helps us understand what may be driving the increased rate of HIV infection seen in human research. These findings suggest other forms of birth control should rapidly replace DMPA shots.”
The investigators did not find an association for combined oral contraceptives (COCs) containing levonorgestrel, or for the 2-monthly injectable contraceptive norethisterone enanthate (NET-EN), although they note that data for NET-EN are limited.
Read the full study, here.
Editor’s Note: It has been brought to our attention that the studies reviewed were not designed to test whether there is any association between contraceptive use and HIV risk, and so it is not yet possible to estimate the potential risk. A randomized clinical trial called ECHO that is designed to determine whether using DMPA, as opposed to other methods of contraception, increase a woman’s risk of acquiring HIV is underway. Results are expected in early 2019. Once the results are available, Contagion® will publish coverage here.
Minor Interruption in ART Approved by NIH for Clinical Trials
New findings released by the National Institutes of Health (NIH) may help the design of future studies aimed at finding strategies to control HIV without the use of drugs. The investigators found that a short-term interruption in antiretroviral therapy (ART) “during a carefully monitored clinical trial does not lead to lasting expansion of the HIV reservoir nor cause irreversible damage to the immune system,” according to a press release on the findings.
Researchers have confirmed that taking ART appropriately can not only extend the lives of those living with HIV, prevent transmission of the virus to others, and reduce levels of the virus in the blood to undetectable levels. Because the virus can remain dormant in latent HIV reservoirs, it is important that individuals on ART are consistent with therapy, else, they run the risk of their viral load increasing when these latent cells “wake up” and start making HIV again.
Knowing this, investigators have been actively developing therapies that would enable sustained remission in the absence of ART. Clinical trials to test these new therapies would require patients to stop ART for a length of time during the trial. This approach is known as analytical treatment interruption (ATI).
To learn more about the effects of ATI, investigators from the NIH’s National Institute of Allergy and Infectious Diseases (NIAID) “analyzed blood samples from 10 volunteers who had participated in a clinical trial evaluating whether infusions of a broadly neutralizing antibody could control HIV in the absence of ART,” according to the press release. After stopping ART, the participants’ HIV reservoirs were shown to expand and their viral loads increased. In addition, immune cell abnormalities were observed in these patients.
The participants restarted ART approximately 22 to 115 days after they had stopped, and the investigators found that 6 to 12 months later, “the size of the HIV reservoirs and the immune parameters returned to levels observed [in the participants] prior to ATI,” according to the press announcement.
According to the investigators, “the findings support the use of ATI in clinical trials to evaluate the efficacy of therapeutic strategies aimed at achieving sustained ART-free remission; however, larger studies that do not involve any interventional drugs are needed to confirm and expand on these results.”
