Possible AIDS medical breakthrough with new study

Researchers have made a major AIDS medical breakthrough in finding a vaccine and a possible functional cure for HIV, thanks to a study that identifies where the virus is still replicating at low levels in the bodies of those that have been infected.

Though medical progress has been made with patients getting powerful antiretroviral drugs such that they eventually become non-infectious, there are still “viral reservoir”-locations and cell types in their bodies where the virus can persist.

As such, though the patients receiving treatment seem to be clear by standard testing, any disruption in their therapy sees the virus return with a vengeance. This means that any functional cure for HIV needs to take out the virus both in the blood– and in the cells and tissues.

AIDS medical breakthrough: looking at the lymphoid tissues

The study from the Northwestern University that was published in the January 7 issue of Nature reported that HIV is still replicating in the lymphoid tissues– even though the patient seem to have been cleared of the virus.

The lymphoid tissues are part of the immune system spread among the body, like lymph nodes, tonsils, and spleen. Prior to the study, researchers thought that the reservoir contained “long-lived infected cells in a resting state”– but no new infected cells.

However, the study discovered that new cells in these areas were being infected by the virus at low enough levels without producing any resistance to the drugs. These are carried throughout the body and when the therapy stops, the cells start the viral production again.

“We now have a path to a cure,” said Dr. Steven Wolinsky, chief of infectious diseases at Northwestern University Feinberg School of Medicine who is an author on the paper.

“The challenge is to deliver drugs at clinically effective concentrations to where the virus continues to replicate within the patient,” Dr. Wolinsky said.

AIDS medical breakthrough: done via mathematical modeling

The group sequenced viral DNA from infected cells that were sampled from the lymph nodes and the bloodstream of three HIV-infected patients.

Taken before and during their first six months of their antiretroviral therapy, the samples showed that the virus was evolving over time– proof that it was replicating– but it wasn’t developing drug resistance.

They then developed a mathematical model to see how the virus might evolve during therapy without developing drug resistance.

Their conclusion is that effective antiretroviral drug concentrations should be delivered into the lymphoid tissue compartments so as to eliminate the viral reservoirs– and ultimately cure the patient of the virus.

“The study is exciting because it really changes how we think about what is happening in treated patients,” said Angela McLean, professor of mathematical biology at the University of Oxford in the UK.

“It helps explain why some strategies that tried to clear the reservoir have failed,” said McLean, a coauthor of the study who led the mathematical modeling in coming up with the AIDS medical breakthrough.