Scientists do not have a clear understanding of how opioid use impacts the immune response in people living with HIV. But two federal grants totaling more than $12 million will fund research into this topic, with the ultimate aim of better understanding which meds are best for people living with HIV and dealing with opioid use disorder (OUD). The grants were awarded to the Philadelphia-based Wistar Institute, which focuses on biomedical research involving cancer, immunology and infectious diseases.

Specifically, Wistar’s HIV Research Program will oversee a consortium of scientists across the nation and abroad as they look into the ways that OUD and medications for OUD (MOUDs) might affect the immune system’s response to HIV treatment.

“We have uncovered a potential link between substance abuse, HIV infection and MOUDs that may determine health outcomes only if the right medication is chosen,” Luis J. Montaner, DVM, DPhil, the study leader, said in a Wistar press release.

It is understood that both HIV and chronic opioid use are linked to activation of the immune system, which can lower CD4 cells and lead to the progression to AIDS in people living with HIV.

What is not well understood, Montaner said, is “how the medications we use to treat OUD impact disease progression and the response to [HIV meds] in people living with HIV.”

Meds to treat OUD either activate or block opioid receptors. The main goal of the research, according to the press release, is to study the role these opioid receptors play in activating the immune system of people who have HIV. Researchers will also explore the effects of the different classes of MOUDs.

The grants come from the National Institute on Drug Abuse (NIDA), part of the National Institutes of Health, and will fund two clinical studies.

One grant of nearly $8.4 million over five years was awarded to an international trial conducted by researchers in France, the United States and Vietnam. The second grant, of about $3.9 million over five years, will be put to use at research centers in the United States.

“We expect the results of this major collaborative effort, which has its hub in Philadelphia, to have broad clinical implications in informing the best pharmacologic strategy for the management of opioid use disease in HIV-infected people starting [antiretrovirals],” said Montaner in the press release. “This is directly relevant in light of the opioid epidemic ongoing in our nation and will help ensure that the right medications are used for both HIV and OUD, with the ultimate objective of saving lives in the future.”