US researchers said Tuesday they have used radioimmunotherapy (RIT) to destroy remaining HIV- infected cells in the blood samples of patients treated with antiretroviral therapy, offering a possible new strategy for curing HIV infection.

Patients infected with HIV can use highly active antiretroviral therapy (HAART) to effectively suppress the replication of the virus in the body, but scientists believe reservoirs of latently infected cells still persist in the body, preventing the possibility of 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, professor at Albert Einstein College of Medicine, said in a statement. "Any strategy for curing HIV infection must include a method to eliminate viral- infected cells."

In her study, Dadachova and colleagues administered RIT to blood samples from 15 HIV patients treated with HAART. RIT, which has historically been employed to treat cancer, uses cells known as monoclonal antibodies to recognize antigens and then bind to them. Antigens are foreign objects like bacteria and viruses that stimulate an immune response in the body.

The monoclonal antibodies are also paired with a radioactive isotope, and when injected into the patient's bloodstream, they deliver radiation to the target cells, killing them.

The researchers found that RIT was able to kill HIV-infected lymphocytes previously treated with HAART, reducing the HIV infection in the blood samples to undetectable levels.

"The elimination of HIV-infected cells with RIT was profound and specific," Dadachova said. "The radionuclide we used delivered radiation only to HIV-infected cells without damaging nearby cells. "

The researchers said next they will conduct clinical trials in HIV patients. The findings were presented at the annual meeting of the Radiological Society of North America.