<<Disclaimer: Verify this information before applying it to your situation.>>

It was suggested in a recent post: "...even the 'gold standard"
biopsy, an invasive & expensive procedure is not all that reliable.
Neither are the blood tests."

I have to take exception to these statements.  Keep in mind that I am
not a doctor.  You can find support in what I am about to say in some of
our reference files, which have been written or reviewed by celiac
medical experts.

The blood tests are used to "screen" for celiac disease.  There are
three tests commonly used:  IgG antigliadin antibodies, IgA antigliadin
antibodies, and IgA endomysial antibodies.  When all three tests come
back positive, there is at least a 90% probability of celiac disease
(CD).  (In some cases, numbers as high as 98% have been quoted).  When
all three tests come back negative, there is less than a 10% probability
of active CD.  So in either of these cases, I would state that the blood
tests are pretty reliable.  See the DIAG-TST reference file for more
information.  (To obtain a copy, visit our web site at
<http://rdz.acor.org/lists/celiac/diag-tst.html>, or send an e-mail
message to [log in to unmask] containing this line in the
body of the message:  GET CELIAC DIAG-TST)

When the test results are mixed, then it is less certain.  Many
gastroenterologists will perform a biopsy if any of the tests come back
positive or if there are sufficient symptoms.  And negative test results
are meaningless if the patient has been on a gluten-free (GF) diet
recently.  The antibodies will only be present in the blood in high
quantities if a celiac has been consuming a normal gluten diet for at
least a month, and often much longer (a fact that many doctors are not
aware of).

In any case, one should not depend on the blood test results for a
diagnosis.  Even if all three tests are positive, it takes a small
intestine biopsy showing villi damage, followed by clinical response to
a GF diet, to diagnose CD.

Is the biopsy reliable?  Again, IF the patient has NOT been on a GF
diet, the biopsy is usually very reliable.  More information about it
is also in the DIAG-TST reference file listed above.

Is the biopsy costly?  Compared to the blood tests, yes.  However, it is
generally outpatient surgery that only takes an hour or so.  You will be
sedated and be off work just that one day.  So it is not nearly as
expensive as many surgeries.  Any medical procedure in a hospital is
expensive, particularly if you are paying for it out of your own pocket,
but compared to most other surgeries it is not too costly.

Is the biopsy invasive (and therefore uncomfortable and/or dangerous)?
My answer is, "No".  I have had a biopsy done on me twice, and my two
celiac children have had the biopsy done once each.  In all four cases
there were no complications.  The procedure is done by inserting a
flexible tube down the throat, through the stomach, and into the first
few feet of the small intestine.  The patient is sedated throughout and
usually has no memory of the surgery.  Sometimes the patient might have
a sore throat afterwards for a day or two, but in our case that did not
happen any of the four times we had the procedure done.  There is always
some risk associated with any surgical procedure, but for a small
intestine biopsy the risks are very small indeed; its just about as safe
a proceedure as you can undergo (in my opinion).

I believe that most of the cases where the results were "inconclusive"
had to do with people who tried the GF diet first, then went back to
eating gluten prior to the testing.  I think in most cases they simply
did not stay on a regular gluten diet long enough to ensure detectable
villi damage.  In other cases, they may not actually be celiacs but may
instead have an allergy-type intolerance to wheat or other gluten-
containing grains.  In the latter case, perhaps allergy testing would
help to prove this one way or the other.

I do know personally of two cases where people went on a GF diet without
a biopsy and then later found out they did not have CD; they had
something else.  The improvement they got on a GF diet was a coincidence
in one case, and was due to some other unnoticed aspect of their change
in diet in the other case.  Both of these individuals are now eating
gluten again and are responding well to the treatments they are
receiving for their medical problems.  Had they continued to just stay
on the GF diet without diagnosis they would not be doing as well as they
are now.  (In both cases it has been over two years since their real
problems were diagnosed.)

Bottom line:  In my opinion, if you are not already on a GF diet it is
definitely better to seek a biopsy-proven diagnosis; don't start the
diet first.  So please, don't try the GF diet first and see how it
works!  Find a gastroenterologist (or for children, a pediatric
gastroenterologist) who is familiar with CD and let them do the
diagnosing.

If you are already on a GF diet and have not been biopsy-diagnosed, then
you have a dilemma.  If gluten obviously makes you ill, then it may not
be practical to go back on a regular gluten diet in order to be biopsied
months later.  On the other hand, it may be worthwhile as you may find
that you are following a GF diet when you don't really need to be.
Either way, make sure you have a gastroenterologist who is familiar with
CD and knows you are on the diet, so he/she can properly determine
if/when to perform any blood tests or biopsies, and whether or not any
results tests would be meaningful.

Remember, these are the opinions of a celiac parent, not a medical
professional.

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|      Jim Lyles               Home: [log in to unmask]      |
| Holly, Michigan, USA    Work: [log in to unmask] |
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