Fetal Cell Transplants Can Work for Parkinson's
Nov. 22, 1999 (Atlanta) -- It's still an investigational procedure -- as
well as a controversial one -- but for the first time, researchers have
evidence that brain cells transplanted from fetal tissue into the brain of a
Parkinson's disease patient work as intended. That is, the cells store and
release dopamine -- a chemical that allows the smooth movement of muscles. It
is the lack of dopamine that is thought to contribute to the rigidity and
tremors seen in the disease.
"The importance of this study is that we've been able to demonstrate
that the implant works," says lead author Paolo Piccini, MD, a neurologist
at Imperial College School of Medicine, Hammersmith Hospital, London. "The
next step is to find an alternative to fetal cells."
Five healthy subjects and one Parkinson's patient -- a 59-year-old man who
underwent a fetal cell transplant to a part of the right side of his brain some
10 years ago, after his symptoms had become debilitating -- participated in the
study. Physically, his recovery was dramatic. Within three years, he was able
to stop taking his medication, called L-dopa, and after about five years he
discontinued therapy to prevent rejection of the transplanted cells.
The patient was put back on a low dose of L-dopa about six years after the
surgery -- but Piccini says it's because the disease began to affect the left
side of his brain, which didn't get a fetal cell transplant. That's the dose he
remains on today -- with just an intermittent tremor and only slight problems
with muscular movements.
Piccini says follow-up tests showed that the operation works, but only in
some patients and not in others. "If the operation does not improve the
patient," she says, "the operation has not been performed properly.
Many things can go wrong. The cells need to be the right age and prepared very
Of course, the real question is whether the operation can ever become widely
available -- given that the current source of the transplant cells is aborted
fetuses. Piccini says she's confident alternate sources will be found. Research
is currently looking into the possible use of animal cells, especially from
pigs -- as well as human cells from other sources. "When we have a
different source of cells," she says, "it will become available to a
large number of patients."
- New evidence shows that fetal tissue transplanted in the brain of a
Parkinson's patient does work by storing and releasing dopamine, which allows
the smooth movement of muscles.
- The patient who participated in this study has been essentially
symptom-free, with only a mild adjustment in his medication for the 10 years
since the procedure.
- While the operation may not ever be widely available with the current
source of tissue -- aborted fetuses -- one researcher believes that other
sources of cells, either from animals or humans, will be developed to make the
operation more feasible.