HIV can hide in bone marrow

Medical researchers have gained a significant insight into how the virus that causes AIDS hides in the body as it dodges medicines that are designed to kill it off. Scientists at the University of Michigan have found that a reservoir of dormant cells in bone marrow serves as a holding cell, from which the virus can roar back into action as soon as the drugs are gone.

The scientists say the research opens the door to a new field of study that could eventually reduce the drug burden on HIV patients, as Ashley Hall reports.

ASHLEY HALL: With the help of combinations of different drugs, doctors have been able to reduce the amount of HIV in the blood of patients to almost nothing. But when the patient stops taking the drugs, the virus springs straight back into action.

KATHLEEN COLLINS: There was good reason to believe that this was due to the virus being able to hide out in so-called reservoirs in a very stable form and it is sitting there poised to reactivate so that when drugs are stopped and the virus can spread again, the virus can rebound.

ASHLEY HALL: Dr Kathleen Collins is an associate professor of internal medicine at the University of Michigan, and the lead author of a study that's been published today in the journal Nature Medicine.

KATHLEEN COLLINS: We looked in the bone marrow which people hadn't really closely looked at before.

ASHLEY HALL: And what did you find when you looked at the bone marrow?

KATHLEEN COLLINS: Well, what we found that there was evidence that HIV in fact, does infect the bone marrow progenitor cells or parent cells that are the source of all of the different blood lineages in the body and moreover that HIV can take on a latent form and so we were able to detect the presence of virus ending cells even after patients had been on therapy for years.

ASHLEY HALL: It's not the first time scientists have found reservoirs of the virus in the body. They've already found HIV hiding out in blood cells called macrophages and in the immune cells known as memory T-cells. But scientists believed there was at least one more major reservoir of the virus in the body and Dr Collins' team thought just maybe that was bone marrow.

KATHLEEN COLLINS: Initially we were very surprised. Certainly it wasn't well understood that HIV had the capacity to affect these cells.

ASHLEY HALL: So is this the major reservoir that you are talking about, do you think?

KATHLEEN COLLINS: It could be. There is a lot of questions that remain to be answered. ...

via The World Today - HIV can hide in bone marrow 08/03/2010.