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Essay:
Another Test Essay is on GlutenFreedom’s site.
Please, read it also.
Contents:
Serum Tests, Small Bowel Biopsies, Stool
Tests, Genetic Tests, Elimination Tests, Conclusions
There
are a number of tests employed in the diagnosis and monitoring of Celiac Disease and Gluten Intolerance. Panels
of serum tests are employed to measure levels of antibodies specifically
associated with the typical digestive symptoms of Celiac Disease. Small
bowel biopsies are performed to check for injury to the villi of the small
bowel. Stool tests measure antibodies
inside the intestines. Genetic tests
look for the ability to make defensive anti-bodies that have the potential of causing
Gluten Intolerance, Celiac Disease, and other conditions if wheat is eaten. Elimination
diets test a diagnosis by watching what happens when the suspected food is
taken out of the diet, and then put back in.
The
traditional "Gold Standard" for diagnosis of Classic Celiac Disease has been positive
serum antibodies coinciding with positive small bowel biopsies. This
standard has been applied under the convention that injury from gluten
does not exist in a patient unless specific antibodies are in the blood and the
small intestine has significant damage.
As of 2004, most doctors rely on this method, that is, these doctors are
only looking for obvious cases of Celiac Disease, and are not yet confident in seeking
a diagnosis of Gluten Intolerance.
Serum Tests
Any
doctor may order panels of blood tests for Celiac Disease. Depending on the doctor and the test lab,
the blood tests may screen for anti-bodies to specific wheat proteins that are associated
with gluten intolerance (gliadin) or anti-bodies
to human tissue that are associated with Celiac Disease (endomysial tissue and tissue
transglutaminase).
Panels
of serum tests for Celiac Disease can easily cost over $400 each and they need
to be repeated over time. But for that
money, serum tests are less than 50% effective in detecting reactions to gluten
unless the patient already has more serious or permanent damage.[1][2]
These serum tests can be useful in strengthening a diagnosis of gluten
sensitivity, particularly in advanced cases, but they cannot be relied upon for
a confident proof that a patient has no reaction to gluten.
Certain
doctors swear by the serum tests – the serum tests have certainly been the
conventional test. But a few doctors
think the serum tests are worse than useless, because it may turn out that the
expensive serum tests and biopsies can do more harm than good because of the
contribution the false negative results make to misdiagnosis.
Small Bowel Biopsies
Samples
of tissue lining the upper small intestine are taken with an instrument
inserted through the throat and stomach.
The tissue is examined for damage under a microscope. This test been a standard but it also has
some reputation for not finding any damage in some patients that nevertheless
have better health on a gluten fee diet.
Sometimes the small bowel damage is patchy and is missed by the biopsy. Sometimes damage is too small to easily find
under a microscope. Sometimes reactions
happen elsewhere in the body without visibly affecting the upper small
intestine.
Small
bowel biopsies can be useful in seeing if the intestines have been very badly
injured, but they cannot be relied upon for a confident proof that a patient
has no reaction to gluten.
Stool Tests
Stool
tests for gliadin sensitivity are performed under the theory that the highest
levels of anti-bodies to any food are found where the food contacts the body,
i.e., inside the intestines.[3][4][5] While rates of false negatives for gliadin
sensitivity can be higher than 50% for blood tests, rates for false negatives
are less than 21% for stool tests.[6] This recently developed test has the
potential of revising most previous studies of diseases associated with Celiac
Disease.
Stool
testing for gliadin sensitivity is presently only available from www.enterolab.com.
Genetic Tests
People
can be tested for the genes related to developing gluten intolerance potential
(Enterolab is one place to test, there
certainly are others). The question
remains, when should a person who has the genes for gluten intolerance go on
the gluten free diet? Is it too late
for the fetus for a pregnant woman to go on the gluten free diet only after she
develops Celiac symptoms? Certainly no child should be fed grains
before 6 months, and pediatricians informed about Celiac Disease recommend no
child with a family history of associated
conditions should be fed gluten before the age of 2 years. But should a child with the genetic
potential for gluten intolerance ever be fed gluten, or is it OK to feed
gluten to such a child until the child develops some symptom
or associated condition? Maybe it
depends on family history. It is probably
not always too late to put a child on a gluten free diet very soon after seizures start, but
it is not known if it is too late to reverse diabetes if the gluten free diet
is started after the diabetic
symptoms start. We just don’t know
yet.
Elimination Tests
This
test involves removing a food from a patient’s diet and watching for clinical
improvements in that patient’s symptoms.
To remove the possibility of coincidental remissions, an Elimination
Test is followed by a Challenge, wherein the suspect food is returned to the
diet and the patient is monitored for a return of symptoms.
Because
of the elevated risks of permanent heath injuries, it is recently recommended
that challenges (which may last for months) “…should not be performed in
children younger than six, and not during puberty.”[7]
Some
doctors state that clinical improvement of symptoms on a Gluten Free Diet
should be the true Gold Standard.
Conclusions
The
serum tests and biopsy have problems with detecting early stages of injury, but
can support a diagnosis when positive.
The stool tests can detect reaction to gluten before any obvious
symptoms can be observed. But the real
proof is improvement of symptoms associated a food from the diet. However, the Gluten Free Diet is not without
complications or errors – please, read “GFD Tips, Pointers,
and Pitfalls” as well as the many guides to the gluten free diet available
on Celiac web sites.
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