University of Minnesota-led research shows HIV rapidly emerges from multiple anatomic sites in long-term treated patients who interrupt therapy

Monday, February 23, 2015

Today’s human immunodeficiency virus (HIV) drugs can help patients live better and longer, but cannot yet, unfortunately, cure. University of Minnesota-led research published today in the Proceedings of the National Academy of Sciences (PNAS), helps shed additional light on why that might be.

The new research finds that multiple variants of the HIV can be found emerging from lymphatic tissues when therapy is interrupted. This was found even among patients who had been on therapy for more than 10 years. The finding shows that the “reservoir” of HIV infection in these patients is much larger and more complex than previously thought, which has significant implications for strategies that might be used to cure the infection.

Lymphatic tissues are part of the body’s immune system, and work to fight bacteria and other potential health risks and include the lymph nodes, spleen and special tissues in the gut. HIV’s significant potential to kill comes from its ability to overwhelm and essentially shut down the immune system, causing AIDS and resulting in the body’s inability to fight off infectious disease.

Previous research released from the University of Minnesota and University of Nebraska Medical Center in January 2014 found drugs used to treat HIV poorly penetrate lymphatic tissues where most HIV replication takes place. This, the authors argued, may be part of the challenge to curing HIV.

“Current thinking is that one or a few latently infected cells can replenish the infection and keep it going over the life of the patient,” said lead investigator and University of Minnesota infectious disease expert Timothy Schacker, M.D., a specialist in HIV and AIDS-related treatment and research. “What this research tells us is that, because the infection rapidly emerges from multiple sites and cells right after treatment is interrupted, current drugs can suppress the virus but can’t really eliminate the infection. It is almost like the current therapies are just keeping a lid on it.”

To achieve their research findings, study authors briefly stopped antiretroviral treatments in 14 immunosuppressed patients and measured the time until the virus was again found in the blood and from where in the body the virus emerged.

Schacker and collaborators continue to work on strategies to more fully suppress virus replication in an effort to reduce this reservoir so that if therapy is interrupted, the virus will not emerge.

Fourteen University of Minnesota authors from a variety of disciplines, in addition to national collaborators, teamed up to help address the complex questions involved in this research. Funding was provided by the National Institutes of Health (NIH) grant no. P01AI074340, and by federal funds from NIH contract HHSN261200800001E.