A cure for human immunodeficiency virus (HIV) could soon become reality, according to a new study. Using a groundbreaking therapy method involving so-called radioimmunotherapy (RIT), researchers from Yeshiva University have successfully eliminated remaining HIV-infected cells in blood samples taken from patients treated with antiretroviral therapy. The findings illuminate an effective drug mechanism that could allow researchers to eliminate the AIDS-causing virus for good.

Although HIV care has been greatly improved in recent years by developments in highly active antiretroviral therapy (HAART), a permanent cure continues to elude the scientific community. This is because HIV, like all viruses, sustains itself by infiltrating and hijacking the body’s own cells. While therapies may restrict the activity of the disease, HIV typically endures in latent reservoirs of infected cells. "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 said in a press release. “Any strategy for curing HIV infection must include a method to eliminate viral-infected cells."

The new study, which was presented at the annual meeting of the Radiological Society of North America (RSNA), shows that this may be accomplished with RIT — a type of targeted therapy capable of delivering cytotoxic radiation to infected cells. Using this method, the scientists were able to clear the infection from blood samples taken from 15 HIV-infected patients treated with HAART. In theory, this means that a combination of RIT and HAART could eliminate the pathogen by killing viral particles as well as infected cells.

A drug capable of targeting infected cells could also help HIV-positive patients control psychiatric symptoms. "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."

According to the Centers for Disease Control and Prevention (CDC), about 50,000 Americans contract HIV each year. Globally, the figure is about 2.5 million. Since the epidemic began, about 30 million people have died from the disease worldwide.

The current study dovetails with a number of earlier research efforts to track down and kill HIV-infected cells. Another example is a study from Oregon Health and Science University, in which researchers show that a cytomegalovirus engineered to express certain proteins may allow the body’s immune system to recognize infected cells and tag them for destruction. This method completely suppressed viral activity in monkeys afflicted with simian immunodeficiency virus (SIV) — the primate version of HIV.