Medical researchers found radioimmunotherapy (RIT) could be an effective weapon against HIV.
The therapy was shown to obliterate remaining human immunodeficiency virus (HIV)-infected cells in patients treated with antiretroviral medications, a Radiology Society of North America news release reported.
Highly active antiretroviral therapy (HAART) is used to reduce the risk associated with HIV, but does not eliminate the virus completely and is not a "permanent cure."
"In an HIV patient on HAART, drugs suppress viral replication, which means they keep the number of viral particles in a patient's bloodstream very low. However, HAART cannot kill the HIV-infected cells," lead author, Ekaterina Dadachova, Ph.D., professor of radiology, microbiology and immunology at Albert Einstein College of Medicine, said. "Any strategy for curing HIV infection must include a method to eliminate viral-infected cells."
RIT is usually used to treat cancer, it uses cloned cells that seek out and destroy antigens ("foreign bacteria or viruses that simulate immune responses in the body").
The antibody designated to bind with a specific antigen is bound to a radioactive isotope partner.
"In RIT, the antibodies bind to the infected cells and kill them by radiation," Dr. Dadachova said in the news release. "When HAART and RIT are used together, they kill the virus and the infected cells, respectively."
The research team "paired the monoclonal antibody (mAb2556) designed to target a protein expressed on the surface of HIV-infected cells with the radionuclide Bismuth-213," the news release reported.
"The elimination of HIV-infected cells with RIT was profound and specific," Dr. Dadachova said. "The radionuclide we used delivered radiation only to HIV-infected cells without damaging nearby cells."
The team found mAb2556 was able to cross the blood-brain barrier and eliminate infected cells. The team found this type of treatment combined with HAART reduced the HIV infection to (undetectable levels).
"Antiretroviral treatment only partially penetrates the blood brain barrier, which means that even if a patient is free of HIV systemically, the virus is still able to rage on in the brain, causing cognitive disorders and mental decline," Dr. Dadachova said. "Our study showed that RIT is able to kill HIV-infected cells both systemically and within the central nervous system."
