WASHINGTON (AP) - The virus that causes AIDS can hide in the bone marrow, avoiding drugs and later awakening to cause illness, according to new research that could point the way toward better treatments for the disease.
Finding that hide-out is a first step, but years of research lie
Dr. Kathleen Collins of the University of Michigan and her
colleagues report in this week's edition of the journal Nature
Medicine that the HIV virus can infect long-lived bone marrow cells
that eventually convert into blood cells.
The virus is dormant in the bone marrow cells, she said, but
when those progenitor cells develop into blood cells, it can be
reactivated and cause renewed infection. The virus kills the new
blood cells and then moves on to infect other cells, said.
"If we're ever going to be able to find a way to get rid of the
cells, the first step is to understand" where a latent infection
can continue, Collins said.
In recent years, drugs have reduced AIDS deaths sharply, but
patients need to keep taking the medicines for life or the
infection comes back, she said. That's an indication that while the
drugs battle the active virus, some of the disease remains hidden
away to flare up once the therapy is stopped.
One hide-out was found earlier in blood cells called
macrophages. Another pool was discovered in memory T-cells, and
research began on attacking those.
But those couldn't account for all the HIV virus still
circulating, Collins said, showing there were more locations to
check out and leading her to study the blood cell progenitors.
Finding these sources of infection is important because
eliminating them would allow AIDS patients to stop taking drugs
after their infection was over. That's critical in countries where
the treatment is hard to afford and deliver.
"I don't know how many people realize that although the drugs
have reduced mortality we still have a long way to go," Collins
said in a telephone interview. "That is mainly because we can't
stop the drugs, people have to take it for a lifetime."
The research was funded by the National Institutes of Health,
Burroughs Wellcome Foundation, University of Michigan, Rackham
Predoctoral Fellowship, National Science Foundation and a Bernard
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