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From:
Jim Lyles <[log in to unmask]>
Date:
Mon, 20 May 1996 23:50:04 EST
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<<Disclaimer:  Verify this information before applying it to your situation.>>
 
                    CD:  Past, Present, and Future
                    -----------------------------
                        by Dr. Robert Truding
                       summarized by Jim Lyles
 
Dr. Robert Truding, a pediatric gastroenterologist out of Beaumont
Hospital, spoke at our April meeting.  What follows are some
highlights of his talk.
 
Dr. Truding first learned of CD as a medical student in the late
60's, when it was not of much interest to the clinicians because so
few people were diagnosed with it.  However, it was the arch typical
intestinal disease; if you wanted to learn about intestinal diseases
then CD was the one to teach you about them.  Not much was known about
viruses and gastroenteritis in those days, whereas with CD you knew
exactly what it was about:  You gave someone who had it gluten, they
got diarrhea; you remove gluten from the diet and they got better.  It
was a perfect setup for teaching medical students about gut diseases.
 
Endoscopies were first done in the 70's.  Prior to that time biopsies
were obtained via a "different route" (laughter).  The endoscopy
allowed several biopsy specimens to be obtained, instead of a single
specimen.  So doctors could take a few extra specimens and take them
back to the laboratory for study.  The "celiac" response could
actually be duplicated in the lab, using a tissue specimen from a
healthy (healed) celiac.  When gluten was applied to the specimen
within 24 hours measurable changes occurred to the specimen.
 
These discoveries raised the question:  How do you now diagnose CD?
For most maladies you have an "operational" definition; you try some
tests and based on the results you make a diagnosis.  Then there are
"symptomatic" illnesses where you don't have a have an operational
definition.  For example, if someone says, "I feel nauseous," there is
no "nauseous meter" that can be used to measure it.  So you look at
the symptoms and try to deduce the cause of them.
 
In the old days, you diagnosed CD by first looking for the symptoms.
Only if someone had the symptoms would you then perform a biopsy and
look for the characteristic celiac villi damage.  Without obvious
symptoms, a biopsy was generally avoided because the technique used
was much less pleasant than a modern-day endoscopy.  It took about an
hour, the patient was not sedated, and in the end you hoped there was
a sample and not just a gob of mucus; otherwise the whole procedure
had to be repeated.  So, people weren't volunteering for the procedure
(more laughter) and you had to see obvious symptoms before you would
put someone through it.
 
A lot of pediatricians avoid the biopsy and simply worked with an
operational definition.  If a child came in with a lot of diarrhea,
they'd put him on a GF diet.  If he got better, they'd decide that was
all that was needed and the child would be labelled a celiac.  The
problem was that it seemed half the kids in the country were being
labeled as celiacs.  When a child has a viral infection, it usually
lasts five days or so.  But 1-2% may last for two weeks.  Usually by
then the pediatrician has been called two or three times and wants to
do something, so he would put the child on a GF diet.  If he got
better (which he would have done anyway if it was a virus) then the
pediatrician would label the child as a celiac.  So we ended up with a
large group of children with an operational diagnosis of CD that was
in fact misleading.  It became an issue from the parenting point of
view when the child reached school age and suddenly the parents no
longer had complete control of the child's diet (school lunches, snack
s, etc.).
 
As an aside:  Most of the research in CD has been done by Europeans.
The Irish, Italians, etc., are where this disease appears to have
originated.  In these populations it appears that one out of every 250
or 500 people has CD.  (There is some dispute over these numbers.)
 
In order to help with this problem of over diagnosis, it was decided
that the best method for diagnosing CD involved three separate
biopsies.  The first step was to perform a biopsy on someone if they
showed symptoms consistent with CD.  If the biopsy was abnormal, then
you'd put them on a GF diet and wait to see if they got better.  If
they did, then somewhere down the line (six months?  two years?)
you'd perform a second biopsy.  If the second biopsy was normal (or at
least improved), then you would add gluten back to the patient's diet.
Finally you'd do a third biopsy (after some indeterminate interval)
and see if the biopsy got worse again.  If it got worse then you
considered the diagnosis of CD to be confirmed and the patient would
then go on a GF diet for life.
 
Three biopsies may seem excessive, but it was needed at that time
because only about 10% of the children that had been labeled as
celiacs actually had CD.
 
So now you had to go back and ask, "What are the clinical symptoms of
CD?"  Most of the people that had the clinical symptoms, and were put
in the textbooks as having CD really did not have CD.  So you had to
discount all the earlier information about celiac symptoms.
 
The Europeans more or less universally adopted the three-biopsy
approach to diagnosing CD.  But this meant that the only people that
got diagnosed were those that had symptoms.  The next question was:
How many celiacs are there that don't have obvious symptoms?  It
appears there are many people that have CD and don't know about it
because they don't have any obvious symptoms.
 
The major breakthrough in solving this problem is the advent of the
antibody blood tests for CD.  The blood tests help to find the celiacs
that don't have symptoms.  Now, the major symptoms of CD are:  you
feel well, you grow well; it is only the people who are unusual who
have symptoms at the time of diagnosis.
 
In the 70's, Dr. Truding worked in an area that had a large Irish and
Italian population; his office saw maybe two pediatric celiac patients
a year.  Nowadays, his office diagnoses five or six a year, because of
the blood test; it helps detect CD where it would otherwise not be
suspected.
 
So what is the definition of CD today?  If you have no symptoms, is it
a medically valid disease?  If you have a relative with CD, and you
have a biopsy that comes back abnormal, does that mean you also have
CD or does it just mean you have a funny-looking biopsy?  If you have
Dermatitis Herpetiformis (DH) and you have a biopsy that comes back
abnormal, does that really mean you have two different diseases (DH
and CD), or is it just an abnormal biopsy?  The bottom line is:  When
people talk about CD, nobody is talking about the same thing.  If you
were trained thirty years ago, it is much different then if you were
trained in the last couple of years.  And now, with the genetic
testing everything is going to change again.
 
The antibody studies are interesting, but there appear to be a lot of
false positives from them.  But we don't actually know if they are all
false positives.  For example, if a child has a positive antibody test
but a negative biopsy, then Dr. Truding would say the child does not
have CD.  Yet 30 years from now the child might see Dr. Alexander as
an adult and this time have a positive biopsy.  Was the diagnosis as a
child correct?
 
In some of the Scandinavian countries they have seen a decrease in the
number of celiacs in the past 15 years.  One theory is that it has to
do with breast-feeding.  But the Belgians say they've seen an increase
in CD over the same span, and they do just as much breast-feeding as
the other countries.
 
When you hear about testing and read about symptoms, keep in mind that
it is all old information.  The next wave of testing is the genetic
tests that we've heard about.  It is going to be helpful in finding
people with a predisposition to CD.  But not everyone with a
predisposition to CD actually gets CD, so then the question will be:
Are we causing people unnecessary concern when we tell them of the
diseases they may be genetically more likely to develop?  Suppose this
genetic testing comes up with other diseases?  For example, suppose
genetic testing done when you are a child shows that you'll develop
cancer when you are 60.  Should you be told?

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