NEWS
Cereal killer
Portable screening technology could make coeliac disease monitoring faster and easier
EARLIER DIAGNOSIS of coeliac
disease, a potentially life-threatening
autoimmune condition caused
by gluten intolerance, could soon
be possible with a £10m (€13m)
project aimed at creating a portable
screening device.
The EC has partly funded a partnership
of 21 organisations across
Europe to work on the CD-MEDICS
(coeliac disease management
monitoring diagnosis using biosensors
and integrated chip systems)
project. The aim is to develop a
testing device that can be used in a
GP’s surgery to diagnose and
monitor people with the disease.
‘We will have a disposable,
completely integrated polymer chip
which is put into an instrument,
such as a small laptop, which will
have embedded communication
abilities so that the results of the
test are automatically sent to the
patient’s electronic medical
records,’ claimed project co-ordinator
Dr Ciara O’Sullivan.
‘You apply a finger prick of
10
blood on to the chip, press a button
and, in 10 to 15 minutes you will
have the results,’ she added.
The researchers aim to produce
three different chips — one for
primary diagnosis, one for regular
monitoring of a person diagnosed
with coeliac disease and one to test
new-born babies so their diet can
be carefully controlled.
For people with the disease,
eating gluten damages the lining of
the gut, which prevents normal
digestion and the absorption of
food and nutrients. The only way to
treat the condition is to maintain a
strict gluten-free diet.
At present, the primary diagnosis
of the condition involves a blood
test that is sent to a pathology lab,
and if the results come back
positive, an individual would
then need to have a minor bowel
biopsy to discover what is happening
to the gut.
The researchers hope to eventually
eliminate the need for a
biopsy by using the device to look
A gluten-free diet, avoiding foods containing wheat, rye and barley, is essential for those with coeliac disease
for genetic markers and certain
autoantibodies associated with the
disease. The presence of HLA-DQ2
and DQ8 genes indicate a person’s
genetic predisposition to the condition.
The scientists aim to sense
autoantibodies such as gliadins.
‘In a primary diagnosis, when
we introduce a drop of blood on to
a chip, it gets divided into two
streams — one to the genetic
analysis and one for the antibody
analysis.
‘For the genetic analysis, we
have a PCR [polymerase chain
reaction — a process for amplifying
DNA] inbuilt into the chip and then
this goes on to be detected by
biosensor arrays. We have specific
probes immobilised on an electrode
surface that detects different
HLA-associated amplicons — the
products of PCR.
‘On the other side, we look at
different antibody levels, transglutaminase,
gliadins and glutens. We
need the two things to be combined
for the primary diagnosis
because very often people have
very low antibody levels. But if you
see there is a predisposition and
they have the symptoms, then you
follow the antibody levels more
closely,’ said O’Sullivan.
The second chip the
researchers plan to develop will
look just at the levels of antibodies,
which will benefit people who
require regular monitoring
after being diagnosed with the
condition.
‘Gluten is often hidden in products,
particularly processed foods.
Some people find it very difficult to
maintain the diet, so this particular
test will be potentially very useful
for people who are newly diagnosed
and trying to get used to the
diet in the first year or two.
It will also allow the doctor to
see pretty quickly whether they are
still ingesting gluten or not. That will
be an improvement because they
do not often use blood testing to
look for that because it means
sending it off to the pathology lab
and so on,’ said Sarah Sleet, chief
executive of Coeliac UK, one of the
consortium members.
Finally, the third chip will have
just the biosensing platform for HLA
genes, which would be useful for
new-born babies who do not have
antibodies and will not have yet
eaten gluten.
While the technology will have
obvious benefits to those with
coeliac disease, O’Sullivan also
highlighted its cost advantages.
‘Predisposition tests are generally
just done for families, so if one
person is diagnosed, the other
members of the family are checked.
It is expensive to do so because it
has to be sent to a lab.
‘The new method is cheap
because the test is all done in situ,
there is no need for sending away,
no specialist personnel and there
are no sterilisation issues,’ she said.
The researchers are aiming to
develop an antibody chip that will
cost €15, a combined chip for €30
and a HLA gene chip for €20.
Anh Nguyen
the EnGIneeR 21 APRIL–4 MAY 2008
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