US doctors in Philadelphia said they have saved a seven-year-old girl
who was close to dying from leukemia with a pioneering use of an
unlikely ally: a modified form of the HIV virus.
After fighting her disease with chemotherapy for almost two years and
suffering two relapses, the young girl “faced grim prospects,” doctors
at Children’s Hospital of Philadelphia said.
So in February this year they agreed to take her on in an experimental program that fought fire with fire.
Helped by a genetically altered HIV virus — stripped of its
devastating properties that cause AIDS — doctors turned the girl’s own
immune cells into a superior force able to rout the “aggressive”
leukemia.
The treatment of Emily Whitehead was one of the very first of its
kind and cannot yet be considered “a magic bullet,” the hospital said.
But in Emily’s case, it apparently worked completely.
First, millions of the girl’s natural immune system cells were
removed. Then the modified HIV virus was used to carry in a new gene
that would boost the immune cells and help them spot, then attack cancer
cells that had previously been able to sneak in “under the radar,” the
hospital said on its website.
Finally the rebooted immune cells were sent back in to do their work.
“The researchers have created a guided missile that locks in on and
kills B cells, thereby attacking B-cell leukemia,” the hospital said.
Pediatric oncologist Stephan Grupp, who cared for the girl, explained
Tuesday that there was never any danger of AIDS during the process.
“The way we get the new gene into the T cells (immune cells) is by
using a virus. This virus was developed from the HIV virus, however all
of the parts of the HIV virus that can cause disease are removed,” he
said in an email.
“It is impossible to catch HIV or any other infection. What’s left is
the property of the HIV virus that allows it to put new genes into
cells.”
During the treatment, Emily became very ill and went into the
intensive care unit, underlining how risky the procedure can be.
However, drugs that partly block the immune reaction were administered,
without interfering with the anti-leukemia action, and she recovered,
the hospital said.
The result was “complete” and best of all, the doctors say, the
boosted immune shield continues “to remain in the patient’s body to
protect against a recurrence of the cancer.”
“She has no leukemia in her body for any test that we can do — even
the most sensitive tests,” Grupp told ABC television. “We need to see
that the remission goes on for a couple of years before we think about
whether she is cured or not. It is too soon to say.”
Grupp said on the Children’s Hospital of Philadelphia website that
cell therapies might eventually replace the more costly, painful bone
marrow transplant treatment, a standard last-ditch defense against
cancer.
“I’ve been meeting with families to discuss bone marrow transplant
for 20 years,” he said. “In almost every meeting, I say that bone marrow
transplant is very hard and that if we had an alternative for children
at that point in treatment, I would be delighted to put myself out of
business. And for the first time, we’re seeing how that might actually
happen.”
Source: AFP
No comments:
Post a Comment