Serum Markers in Gluten Challenge

The diagnosis of celiac disease carries with it important ramifications. Celiac disease is a
systemic immunologic disorder in which the sentinel lesion is an enteropathy triggered by
polypeptides derived primarily from the gliadin proteins found in wheat, rye and barley.
Ingestion of the offending proteins leads to inflammation and intestinal mucosal damage,
which results in a spectrum of abdominal symptoms, increased intestinal permeability,
malabsorption, occult gastrointestinal bleeding and diarrhea. Systemic manifestations of
celiac disease include a myriad of conditions including malignancy and autoimmune disease.

The only accepted treatment for celiac disease is lifelong adherence to a gluten free diet.
Adherence to this diet, simply put avoiding all foods containing even small amounts of wheat,
rye and barley, has been shown to lead to improvement in the majority of related problems and
normalization of all standard diagnostic tests. Because of this many individuals who present
for evaluation of possible celiac disease but who are already on a gluten free diet cannot be
tested accurately as there is currently no way of differentiating between healthy individuals
and individuals with well treated celiac disease. The standard practice in such cases is to
perform a 'Gluten Challenge' whereby the patient eats the equivalent of 2 slices of bread per
day for six to eight weeks before returning for evaluation with serologic testing and
endoscopy with duodenal biopsy. The use of the gluten challenge in clinical practice is
limited by patient symptoms and resistance to such a long test period, after which it may
take a number of weeks for the intestine to heal and the symptoms to resolve. Autoantibodies
to tissue transglutaminase or antibodies to deamidated gliadin, while being excellent tools
to predict celiac disease in patients who have been on a long-term gluten containing diet,
display low sensitivities to detect short-term and/or recent gluten exposure. For this
reason, it would be very useful if novel circulating markers could be identified that
indicate the presence of celiac disease and in particular would provide an early and less
invasive marker of a positive response to gluten challenge.

Inclusion Criteria:

1. Age between 17 and 72 years, inclusive.

2. Subject must have been diagnosed with celiac disease by duodenal / jejunal biopsy at
least 6 months prior to entrance into the study.

3. Subject has Anti-Tissue Transglutaminase (anti-tTG) ≤ 20 EU as measured by serology.

4. Subject must be on a gluten-free diet for at least the past 6 months.

5. Female subjects should be either post-menopausal (amenorrhea for at least 24
consecutive months), surgically sterile, or women of child-bearing potential (WOCP)
with a negative urine beta human chorionic gonadotropin (HCG) pregnancy test prior to
entering the study and who are using or agree to use acceptable methods of
contraception. Abstinence is an acceptable means of avoiding pregnancy as long as the
subject agrees to use contraception if they become sexually active. Acceptable
contraceptives include intrauterine devices (IUDs), hormonal contraceptives (oral,
depo, patch or injectable) in use for one month prior to screening and double barrier
methods such as condoms or diaphragms with spermicidal gel or foam.

6. Subject must sign an Institutional Review Board approved informed consent and agree to
complete required clinic visits.

7. BMI between 18.5 and 38, inclusive.

Exclusion Criteria:

1. Subject has Anti-Tissue Transglutaminase (anti-tTG) > 20 EU as measured by serology.

2. Subject has other food intolerances or food allergies (other than celiac disease) that
would interfere with the conduct of the study).

3. Subject has a history of severe acute symptomatic reactions to sporadic gluten
ingestion

4. Subject has any chronic active GI disease other than celiac disease (e.g. Crohn's
disease, IBS).

5. Subjects with symptomatic neurological or psychiatric disease(s) that would interfere
with the conduct of the study.

6. Subject has clinically significant abnormal laboratory test results at the screening
visit or as determined by the Principal Investigator

7. Subject is pregnant or breast feeding.

8. Subject (premenopausal females) is sexually active without contraception.

9. Subject should not have been on steroids in the past 3 months.

10. Subject is deemed inappropriate by the Principal Investigator.