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Ninth International Symposium on Celiac Disease<2>
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August 10-13, 2000
a synopsis by Amy Eliezer, MS, RD
Experts engaged in research relating to celiac disease (CD) from many
disciplines and many parts of the world convened in Baltimore,
Maryland for three full days. Reporting on their research, they
covered the genetic, epidemiological, and immunological aspects of CD.
They also discussed diagnostic methods, issues concerning the
gluten-free diet, and the enormous problems of CD diagnosis due to the
diversity of its clinical presentations.
Epidemiology (Occurrence) of CD
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Celiac disease is estimated to exist in as many as 1% of the world's
population. Clinical presentation of symptoms and signs of CD vary
greatly, presenting a difficult diagnostic picture. Any part of the
body, from the brain to the feet, can be symptomatic of gluten
intolerance. Approximately 226 different complaints can manifest
gluten intolerance. Therefore, "atypical" presentations are not
usually atypical.
Conclusion: The diagnosis of celiac disease is very important, and
for the physician, very difficult.
Prevalence in the U.S. general population is probably between 1:126
and 1:250. Given the presumed genetic inheritance, the prevalence
among first degree relatives of celiac patients is about 1:13, while
in second-degree relatives the prevalence is also high, about l:12.
Therefore the risk of having CD is 30-45 times greater in relatives of
celiacs than in the general population. It is notable that the vast
majority of pediatric celiacs are asymptomatic.
The potential for eventual secondary complications in asymptomatic
celiacs highlights the need for childhood screening of the general
population.
New Protocol for Diagnosis of CD
--------------------------------
There are new, revised diagnostic criteria established by ESPGHAN
(European Society of Pediatric Gastroenterology, Hepatology, and
Nutrition). Fortunately, we no longer have to rely on the glucose
tolerance, fecal fat, or d-xylose tests for diagnosis. (Even more
outmoded is the 1970's protocol of biopsying, putting the patient on a
gluten-free diet, challenging him/her with gluten and re biopsying,
and then a gluten-free diet and re-biopsying for a third time.)
Until there is 100% reliable serology, however, a biopsy is still
required to confirm a positive serological diagnosis.
Diagnosis of and Screening for CD
---------------------------------
Currently, there are two stages of testing; serology (blood) tests and
biopsy. Blood tests are usually done first, to be followed by biopsy
for confirmation of diagnosis. All methods of biopsy require up to 8
specimens from various areas of the small intestine in order to detect
all possible damage.
When endoscopy is also used to obtain biopsy specimens, the physician
can actually see the small intestine, and see if there is scalloping
or other lesions. While people with partial atrophy seemed normal in
the past, we now can find earlier stages of damage. Here also, biopsy
specimens must be cut and prepared in a certain way or a test's
accuracy is compromised.
Four serological (blood) tests:
* The Antigliadin IgG antibody test is highly sensitive but low in
specificity.
* The IgA antibody test is low in sensitivity but more specific. It
is used together with the IgG test above.
* The Antiendomysial, or EMA, test is both highly sensitive and
specific. However, it is a subjective test and its reliability
depends on a skilled technician and a celiac-experienced
pathologist. It is also expensive.
* A new test called the tissue Transglutaminase test (tTG) is
commercially available. It is also known as the "Dot Blot" test.
The tTG compound comes on a paper strip. A drop of the patient's
blood is put onto the paper strip. This test is inexpensive, and
easy to read. (There may be some false positive results.)
However, it is expected to be reliable when used for follow-up
compliance to the GF diet.
Diagnostic Implications
-----------------------
A celiac's diagnosis is difficult not only due to the diversity of
symptoms, but also because of other variations: "silent", or hidden
celiacs have NO symptoms, but they do have a positive serology test.
(Osteoporosis or anemia may be present in these people.) Other
celiacs have a negative serology test (because of an immune
deficiency), but they have a positive biopsy. Some celiac children go
back on a normal (gluten-containing) diet after diagnosis and do not
suffer symptomatic relapse for a very long time. However, there is no
natural recovery for untreated celiac disease patients.
Which Adults Should Be Screened for CD?
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Anyone with osteoporosis, IDDM (Type I Diabetes), chronic unexplained
anemia, or thyroid problems.
Follow-up After Diagnosis
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At the first visit after diagnosis, the physician explains the
disease, shows pictures of the intestine, and tells the patient the
possible consequences of damage related to symptoms, i.e. malaise,
fatigue, depression and cancer. He describes the difference between
being healed and being cured. (A patient is never cured; just healed
and healthy.) Routine tests include bone density, Vitamin B12, TSH,
iron, and carotene. He checks for osteoporosis and gives a variety of
vitamin supplements: calcium, iron, folate, and the fat-soluble
vitamins.
Monitoring the Gluten Free Diet
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* After the first month, check for symptoms.
* Within 3-6 months, deficiencies should be corrected. (Vitamin D
deficiency may continue longer.)
* At 6 months redo the serology testing. It should be negative if
the diet is being followed.
* At 1 year perhaps a re-biopsy.
* Follow-up visits every 1-2 years thereafter.
* Osteopenia is very common in both men and women. A few have
osteomalacia.
Follow-up Medical Problems
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If the patient is non-responsive, repeat the diet instruction. Check
for lymphocytic colitis (collagenous) and pancreatic insufficiency.
(Over-the-counter pancreatic enzyme supplements are no good). Also,
check for bacterial overgrowth. For the vast majority of diagnosed
celiacs, a gluten-free diet that fails to heal is due to inadvertent
gluten consumption. A positive serology test will confirm this.
Refractory Celiac Disease
-------------------------
Definition: The lack of a clinical or histological response to a
gluten-free diet.
In one study, more than half of the patients with refractory CD had
jejunoileitis, and were more likely to develop small intestinal
lymphoma (i.e. cancer). Serology tests in these patients are
unreliable and should not be used for monitoring gluten-free diet
compliance. The prevalence of refractory CD is low; at less than 1%
of celiac patients.
Other Rare Complications
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In rare cases however, the problem is microscopic colitis, or T Cell
lymphoma (cancer). There are shared HLA genotypes between colitis and
CD. In colitis, the colon looks like the small intestine looks in
celiac disease. With microscopic colitis, one doctor prescribes Pepto
Bismol for 8 weeks, and he also puts those patients on a gluten free
diet. [Results have been variable--Dr. Alexander, TCCSSG's physician
advisor]
Mental Status
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The depression often seen in untreated celiacs may be the result of a
serotonin deficiency. The progression is seen as chronic inflammation
in the intestines causing a leaky gut, letting large peptides into the
body. This starts a chain of events that ultimately causes a
serotonin deficiency and thus depression. In adults, this depression
manifests itself by fatigue, irritability, and weight loss. In
children, depression manifests itself by withdrawal, behavioral
disorders, and/or excess dependence on parents (clinging). However,
there is no unique set of psychological traits in celiacs.
Fertility
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Untreated celiacs (i.e. on a normal diet) have increased infertility
problems and miscarriages. They also exhibit decreased breast-
feeding, and low birth weight infants with lower Apgar scores.
Therefore, women who have recurrent spontaneous abortions should be
checked for celiac disease.
Neurology
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Ataxia (lack of muscle coordination) or peripheral neuropathy are
sometimes seen in CD. A small percentage of celiacs have headaches
that are usually 100% cured by a gluten-free diet. The problem is
caused by IgG (antigliadin antibodies) circulating in the brain; i.e.,
it is immune-mediated. When the GF diet is followed, these antibodies
disappear from the brain.
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