(NBC NEWS) -- Two men who had grueling bone marrow treatments for cancer are
enjoying a happy side effect: They appear free of the AIDS virus,
researchers reported on Wednesday.
The doctors are not quite
ready to call it a cure, but they say the men have stopped taking HIV
drugs and have remained free of the virus for almost four months in one
case and almost two months in another.
"While these results are
exciting, they do not yet indicate that the men have been cured," says
Dr. Timothy Henrich of Brigham and Women's Hospital and Harvard Medical
School in Boston.
The cases of the two men, who don't want their names released, were first reported at an international AIDS conference in Washington last July. Henrich,
Dr. Daniel Kuritzkes and colleagues had actively looked for HIV patients
with leukemia or lymphoma who had received bone marrow stem cell
They wanted to replicate the case of Timothy Brown,
also known as the "Berlin patient," who was treated for leukemia with a
bone marrow transplant that happened to come from a donor with a
genetic mutation that makes immune cells resist HIV infection. The
transplant replaced his own infected cells with healthy, AIDS-resistant
cells, and he remains free of the virus more than five years later.
found three patients who had remained on HIV regimens while undergoing
bone marrow transplants, which are designed to destroy the cancer and
replace diseased blood and immune systems with healthy ones from donors.
The patients' own bone marrow is destroyed, usually with
chemotherapy or radiation, and replaced with a tissue-matched transplant
from a donor.
Henrich said at the time that the AIDS cocktails likely protected the new transplanted bone marrow from infection.
patient is HIV-free nearly three years later, and the other more than
four years later. Each made the choice to discontinue his AIDS drugs a
few weeks ago.
Now there is still no evidence the virus is
anywhere in their bodies, Henrich says. He'll report his findings to a
meeting of the International AIDS Society in Malaysia.
"Up to week
14 for both patients, we continue to be unable to detect (HIV) DNA in
their cells or virus in their blood," Henrich says.
very deeply this time -- much more deeply than last time." They looked
in the immune cells that HIV attacks, especially the CD4 and CD8
T-cells. They also took samples of rectal tissue from one patient to
make sure no virus was hiding there. The one place they didn't look was
in the brain. "We didn't feel the risk of that was justified," Henrich
The patients will get weekly blood tests for at least a year
or more, says Henrich. "We don't even know where some of the HIV might
be hiding," he says.
The case raises a big question that some AIDS specialists never dreamed they would be asking: When do you declare a cure?
never is an 'aha' moment when you suddenly can declare a cure," says
Kevin Robert Frost, CEO of thee Foundation for AIDS Research (amFAR),
which helped pay for the study. "it is impossible to prove the absence
The human immunodeficiency virus that causes AIDS
is transmitted sexually, in blood, on infected needles, at birth and in
HIV drugs called antiretroviral therapy can keep
the virus suppressed to such low levels that patients are healthy and
their immune systems are not damaged. People taking the drugs are also
less likely to infect someone else, and studies show that uninfected
people who take them are much less likely to become infected.
doctors believe the drugs can stop the virus from infecting cells and,
perhaps, from hiding out in the body. But people who are infected and
who stop taking their drugs almost always have the virus come back at
some point, so it does lurk in what are known as reservoirs.
says doctors have been debating when and if to declare the patients
cured. Timothy Brown, the Berlin patient, says he is. "What is the
definition of a cure? " Henrich asked. "Even with the Berlin patient,
who is five years out, it could come back, although the chances are very
A third patient who also seemed HIV-free died when his
lymphoma returned, Henrich said. It's clear this isn't a treatment for
the average HIV patient, but it does show it may be possible to
eradicate the virus. It also suggests that HIV patients who do get
leukemia or lymphoma should stay on their HIV drugs during treatment.
Then there is the widely reported case of a baby in Mississippi whose HIV infection disappeared after
unusually early and aggressive drug treatment. "She's doing quite well,"
says Dr. Hannah Gay of the University of Mississippi Medical Center,
who treated the child.
The child, who lives in rural Mississippi,
is now 3 years old and still has no evidence of active HIV infection.
She was born to a mother who didn't know until right before she gave
birth that she had HIV, and when the child was diagnosed with the virus,
Dr. Gay decided on an unusual course of aggressive treatment.
colleagues reported at another AIDS meeting in March that the treatment
appears to have eradicated what's known as "replication-capable" virus,
although some tests do show evidence of HIV in the child's body.
"We still don't know exactly when to declare a cure and that's the case even with the Berlin patient," Gay told NBC News.
baby is doing great. It is our intention to keep following her closely.
We know that ... there is the possibility she has some cells hidden there
that are infected with replication-competent virus that somewhere down
the line could come back out. We are aware that is a possibility," Gay
Frost says it may change the direction of research. Timothy
Brown was given transplants of bone marrow cells from a patient with a
mutation in a gene called CCR5, which makes people resistant to HIV
infection. But the latest two patients got ordinary cells.
people thought that was a critical component of what had been achieved
in the Berlin patient. I think this changes the game," Frost told NBC
Henrich says it is possible that transplanted immune system
cells destroyed any remaining HIV-infected cells as part of their normal
and expected scavenging of alien cells -- which would include any of
the patients' own immune cells left after the pre-transplant
Frost said he had not heard of any other patient
going as long at 15 weeks without HIV drugs without the virus coming
back. But he is nonetheless cautious. "My sense is we going to be at
least a year out before anybody is going to be prepared to make claims
about what these cases really mean," he says. "You want to be at least a
year out before you would consider declaring a victory."
"Whatever the outcome, we will have learned more about what it will take
to cure HIV," added amfAR research director Dr. Rowena Johnston.