Sure, romantic rejection can
make one's heart ache, but it's a cakewalk next to a heart
transplant rejection. Organ transplant surgeries, like
singles bars, may bring people and hearts together � but
what can you do should the new couple reject one another?
Two new studies will try � like marriage counsellors �
to make these matches last.
One of these promising studies,
called Diagnostic Applications of Microarrays on Organ
Transplantation, is part of the Genome Canada project.
Several Alberta institutions will tackle the study,
which has received a generous $11 million in funding.
"We've been doing preliminary studies
for a year and a half with gene chips," says Project
Leader Dr Phil Halloran, professor at the University
of Alberta and editor of the American Journal of
Transplantation. "The goal of the [Genome Canada]
project is to understand the mechanisms by which rejection
affects the tissues in the human," he says. "We can
do that by examining parallel processes in mice that
have been engineered in instructive ways so that we
can see the function of their genes," he adds. "Applying
this knowledge to human tissue, we can come up with
a new set of diagnostic tools to help us manage people
and show us the molecules we should be targeting with
the next generation of immunosuppressive agents."
JUST
GIVE ME A SIGN
Dr Halloran hopes that the project will identify indicators
of organ rejection � so they can be managed to prevent
organ damage from occurring. He foresees using rejection
indicators much like how we now use blood pressure and
cholesterol levels to manage heart disease.
"Currently, the whole basis of
what we do clinically in managing transplantation and
other diseases is to wait for injury to occur," says
Dr Halloran. "We shouldn't be doing it that way. A kidney
transplant is a kidney, and when we learn about the
way a kidney transplant behaves, we learn more about
the way a kidney behaves, which ultimately should help
us prevent kidney failure."
STEMMING
REJECTION
For Dr Miodrag Stojkovic, a researcher at the Institute
of Human Genetics at the University of Newcastle upon
Tyne, embryos hold the key to better transplant matchmaking.
His project, "Somatic cell nuclear replacement as a
source of human embryonic stems," was just granted a
licence in August by Britain's Human Fertilisation and
Embryology Authority.
"The ultimate goal is to derive
human embryonic stem (ES) cells from cloned embryos,"
says Dr Stojkovic. The process involves replacing the
nucleus of an unfertilized egg with the nucleus of a
cell from a patient's body. ES cells will then be derived
from the resulting blastocyst. "This is very important,"
says Dr Stojkovic, "because these human embryonic stem
cells have nearly 100% of the genetic background of
the patient."
BIRDS
OF A FEATHER
The process of nucleus transfer has many potential benefits
for those with a well-grounded fear of rejection. For
instance, Dr Stojkovic hopes his project will produce
beta (islet) cells for transplantation in patients with
Type I diabetes.
"Embryonic stem cells are the source
of all cell types," says Dr Stojkovic, "and have the
possibility of differentiating into nearly all stem
cell types." In culture dishes he'll attempt to coax
these ES cells into differentiating into islet cells.
If all goes according to plan, the islet cells transplanted
into the patient � from whom the transplanted nucleus
was derived � shouldn't stir up a rejection response
thanks to the near-perfect genetic match.
With matches like this, transplanted
organs and the patients who receive them may well live
together, happily ever after.
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