Doctors in
Berlin, Germany, are reporting that a 42-year-old American living in
that city may have eliminated the virus from his body after a bone
marrow transplant.

According
to the Wall Street Journal report, the man was suffering from leukemia
and AIDS, and while he continues to receive treatment for the leukemia,
the virus has not reappeared in his blood in 600 days.

Traditionally, when a person on antiretroviral medication to treat
HIV stops taking the pills, the virus bursts back with a flurry of
activity. But this unidentified patient stopped taking the medication
and has not had any evidence of the virus in his blood since.

The report explains that doctors believe this is due to the man’s
leukemia doctor’s use of bone marrow from a donor who had genetic
immunity to HIV infection.

The development suggests a potential new therapeutic
avenue and comes as the search for a cure has adopted new urgency. Many
fear that current AIDS drugs aren’t sustainable. Known as
antiretrovirals, the medications prevent the virus from replicating but
must be taken every day for life and are expensive for poor countries
where the disease runs rampant. Last year, AIDS killed two million
people; 2.7 million more contracted the virus, so treatment costs will
keep ballooning.

So what does this case indicate to experts? The Journal reports:

While cautioning that the Berlin case could be a fluke,
David Baltimore, who won a Nobel prize for his research on tumor
viruses, deemed it “a very good sign” and a virtual “proof of
principle” for gene-therapy approaches. Dr. Baltimore and his
colleague, University of California at Los Angeles researcher Irvin
Chen, have developed a gene therapy strategy against HIV that works in
a similar way to the Berlin case. Drs. Baltimore and Chen have formed a
private company to develop the therapy.

“Sounds like good news so far — I’d be hesitant to call it a cure,”
Mark Peterson of the Michigan Positive Action Coalition, or MI-POZ, a
group of politically active HIV-positive people in Michigan, said in an e-mail. Peterson went on to say that the news
underscored the importance of research into a specific class of drugs
that stop the virus from invading human cells in the first place.

This is possibly very important news in the fight against HIV.

When antiretrovirals were first introduced, and viral loads (the
number of viral particles in the blood) were found to have been
suppressed to undetectable, doctors thought that eventually cells
harboring HIV would die off and the person would be HIV-free. That did
not happen. Researchers discovered that the virus incorporated itself
into the genetic makeup of the infected person and waited for the
opportunity to reignite the infection.

But in 1996, researchers also made another startling discovery, the Journal reports:

…researchers discovered that some gay men astonishingly
remained uninfected despite engaging in very risky sex with as many as
hundreds of partners. These men had inherited a mutation from both
their parents that made them virtually immune to HIV.

The mutation prevents a molecule called CCR5 from appearing on the
surface of cells. CCR5 acts as a kind of door for the virus. Since most
HIV strains must bind to CCR5 to enter cells, the mutation bars the
virus from entering. A new AIDS drug, Selzentry, made by Pfizer Inc.,
doesn’t attack HIV itself but works by blocking CCR5.

Craig Covey, executive director of the Midwest AIDS Prevention
Project based in Ferndale, said he had not heard anything about the
case or the reports, and was unable to comment.