Disease: Celiac Disease
Disease: Celiac Disease
Subtopic: Diagnosis: clinical and subclinical categorizations
First Task is to create
4 page summary of your research. Essentially about the diagnosis
and the clinical and subclinical categorization. (this info is to
present to people so it needs to be detailed but easy to read when
presenting)
● Make sure the summary is in order. I want you to talk about the
diagnosis first and then clinical categories and finally
subclinical
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A prospective, double-blind, placebo-controlled trial to establish a
safe gluten threshold for patients with celiac disease1–3
Carlo Catassi, Elisabetta Fabiani, Giuseppe Iacono, Cinzia D’Agate, Ruggiero Francavilla, Federico Biagi,
Umberto Volta, Salvatore Accomando, Antonio Picarelli, Italo De Vitis, Giovanna Pianelli, Rosaria Gesuita,
Flavia Carle, Alessandra Mandolesi, Italo Bearzi, and Alessio Fasano
ABSTRACT
Background: Treatment of celiac disease (CD) is based on the
avoidance of gluten-containing food. However, it is not known
whether trace amounts of gluten are harmful to treated patients.
Objective: The objective was to establish the safety threshold of
prolonged exposure to trace amounts of gluten (ie, contaminating
gluten).
Design: This was a multicenter, double-blind, placebo-controlled,
andomized trial in 49 adults with biopsy-proven CD who were
eing treated with a gluten-free diet (GFD) for �2 y. The back-
ground daily gluten intake was maintained at �5 mg. After a baseline
evaluation (t0), patients were assigned to ingest daily for 90 d a
capsule containing 0, 10, or 50 mg gluten. Clinical, serologic, and
histologic evaluations of the small intestine were performed at t0 and
after the gluten microchallenge (t1).
Results: At t0, the median villous height/crypt depth (Vh/Cd) in the
small-intestinal mucosa was significantly lower and the intraepithe-
lial lymphocyte (IEL) count (� 100 enterocytes) significantly highe
in the CD patients (Vh/Cd: 2.20; 95% CI: 2.11, 2.89; IEL: 27; 95%
CI: 23, 34) than in 20 non-CD control subjects (Vh/Cd: 2.87; 95% CI:
2.50, 3.09; IEL: 22; 95% CI: 18, 24). One patient (challenged with 10
mg gluten) developed a clinical relapse. At t1, the percentage change
in Vh/Cd was 9% (95% CI: 3%, 15%) in the placebo group (n � 13),
�1% (�18%, 68%) in the 10-mg group (n � 13), and �20%
(�22%, �13%) in the 50-mg group (n � 13). No significant differ-
ences in the IEL count were found between the 3 groups.
Conclusions: The ingestion of contaminating gluten should be kept
lower than 50 mg/d in the treatment of CD. Am J Clin Nutr 2007;
85:160–6.
KEY WORDS Gastroenterology, celiac disease, gluten toxic-
ity, small-intestinal morphometry, gluten-free diet, gluten threshold
in gluten-free food
INTRODUCTION
Celiac disease (CD) is an immune-mediated enteropathy trig-
gered by the ingestion of gluten—the major protein fraction
contained in the cereals wheat, rye, and barley—in genetically
susceptible persons. CD is a life-long disorder affecting 0.5–1%
of the general population worldwide. The standard treatment of
CD involves the consumption of a diet completely devoid of
gluten proteins, a so-called gluten-free diet (GFD). In the long
term (1–2 y), a GFD is associated with clinical, serologic, and
histologic remission (1). However, it is almost impossible to
maintain a diet with a zero gluten content because gluten con-
tamination is very common in food. “Hidden” gluten (used as a
protein filler) may be found in commercially available products,
such as sausages, soups, soy sauces, and ice cream. Even prod-
ucts specifically targeted to dietary treatment of CD may contain
tiny amounts of gluten proteins, either because of the cross-
contamination of originally gluten-free cereals during their mill-
ing, storage, and manipulation or because of the presence of
wheat starch as a major ingredient.
The potential toxicity of trace amounts of gluten is still un-
clear. We previously showed in treated CD patients that the 4-wk
ingestion of 100–500 mg gliadin/d (roughly equivalent to 200–
1000 mg gluten) is able to cause measurable changes in the
architecture of the small-intestinal mucosa (2). Only limited data
are available on the toxicity of lower doses of gluten (3–6). This
is an important issue because the daily ingestion of contaminat-
ing gluten in apparently well-treated CD patients is most likely to
ange from 5 to 50 mg.
Establishing a safe threshold of gluten consumption for CD
patients is a matter of major public health importance, particu-
larly in light of the recent reports concerning the high prevalence
1 From the Center For Celiac Research, University of Maryland School of
Medicine, Baltimore, MD (CC and AF); the Department of Pediatrics, Uni-
versità Politecnica delle Marche, Ancona, Italy (CC, EF, and GP); the De-
partment of Gastroenterology, Children Hospital, Palermo, Italy (GI); the
University Department of Gastroenterology, Catania, Italy (CD); the Uni-
versity Department of Pediatrics, Bari, Italy (RF); the University Department
of Gastroenterology, Pavia, Italy (FB); the University Department of Internal
Medicine, Bologna, Italy (UV); the University Department of Pediatrics,
Palermo, Italy (SA); the Department of Gastroenterology, “La Sapienza”
University, Rome, Italy (AP); the Gastroenterology Unit, Catholic Univer-
sity of Sacred Heart, Rome, Italy (ID); the Department of Biostatistics,
Università Politecnica delle Marche, Ancona, Italy (RG and FC); the De-
partment of Pathology, Università Politecnica delle Marche, Ancona, Italy
(AM and IB).
2 Supported in part by the Italian Celiac Society. Purified gluten was kindly
supplied by Bruno Ja
y while working for the Tate & Lyle Group (United
Kingdom).
3 Reprints not available. Address co
espondence to A Fasano, Muco-
sal Biology Research Center, University of Maryland School of Medi-
cine, 20 Penn Street, Room 345, Baltimore, MD XXXXXXXXXXE-mail:
afasano@m
c.umaryland.edu.
Received May 26, 2006.
Accepted for publication August 28, 2006.
160 Am J Clin Nutr 2007;85:160–6. Printed in USA. © 2007 American Society for Nutrition
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of the disease worldwide (7, 8). The recent National Institutes of
Health Consensus Conference position on CD estimated that as
many as 3 million people in the United States are affected by CD.
These findings, together with the recently approved Food Aller-
gen Labeling and Consumer Protection Act, created a vacuum in
terms of health care policy, food safety, legislative guidelines,
and industry-related legal liability that needs to be filled to allow
the Food and Drug Administration’s governmental mandate to
implement the new bill by 2006. The “gluten threshold” topic is
cu
ently under evaluation by the Codex Alimentarius, the
WHO/FAO commission that is in charge of setting food stan-
dards at the international level. To address the aforementioned
issues we undertook a prospective, double-blind, placebo-
controlled multicenter trial to investigate the toxicity of gluten
traces in the celiac diet, with the cooperation and the sponsorship
of the Italian Celiac Society (Associazione Italiana Celiachia;
AIC). We report herein the final results of this study.
SUBJECTS AND METHODS
Study design
This was a prospective, multicenter, placebo-controlled,
double-blind, randomized trial performed between the years
2001 and 2004. The patients were adults with biopsy-proven CD
who had consumed a GFD for �2 y and were in apparent good
health. Patients were excluded if they 1) were younger than 18 y,
2) were poorly compliant with the GFD, 3) were positive fo
anti-tissue transglutaminase (tTG) antibodies or had a villous
height/crypt depth (Vh/Cd) �1.5 at baseline (t0), or 4) associated
conditions, such as selective immunoglobulin A (IgA) defi-
ciency or other autoimmune diseases. Patients that qualified fo
the study were interviewed and gave their informed consent.
Control subjects (only for comparison of the morphometric val-
ues at t0) were adults who were negative for serologic CD mark-
ers and for Helicobacter pylori (urea
eath test) and were un-
dergoing upper endoscopy for diagnostic purposes.
The patients qualifying for the trial underwent a screening and
a dietary interview (t�1). They were asked to maintain a strict
GFD during the study period, ie, avoidance of any possible
source of gluten contamination (such as restaurant meals). The
only cereal-based food they were allowed to eat was the special
GFD products on the market in Italy, which Italian law estab-
lishes as having a gluten contamination of �20 ppm (20 ppm �
20 mg/kg product). After 1 mo the subjects returned for a baseline
evaluation (t0), which involved 1) a clinical examination, 2) a
dietary interview, 3) blood collection for serum anti-tTG anti-
ody and antigliadin antibody (AGA) measurements, and 4) an
endoscopy and small-intestinal biopsy. While still adhering to a
strict GFD, the patients were randomly assigned (by the coordi-
nating center) to ingest daily and for 90 d a capsule containing
either 10 mg purified gluten, 50 mg purified gluten, or 50 mg
cornstarch as a placebo (double-blind microchallenge). Afte
completing the 3-mo microchallenge (t1), the patients repeated
the same clinical, serologic, and histologic tests as at t0. If any
patient had symptoms suggestive of CD relapse during the mi-
crochallenge, the protocol was stopped and the patient was asked
to perform the t1 evaluation before dropping out of the study.
From t�1 to t1, the adherence to both the GFD and the study
protocol and clinical progress were checked weekly by telephone
interview. The study protocol was approved by the Ethical Com-
mittee of the Università Politecnica delle Marche, Ancona, Italy.
Methods
Purified gluten was used for the preparation of the capsules
(Amygluten 110; Tate & Lyle PLC, London, United Kingdom).
We used whole gluten rather than single gluten fractions because
it has been shown that not only gliadins, but also glutenins (the
other major component of gluten), contain toxic epitopes (9).
Gelatin capsules that would quickly dissolve in the stomach were
prepared by the pharmacy of the coordinating center. On a dry
weight basis, the capsules contained 10 mg raw gluten, 50 mg raw
gluten, or 50 mg cornstarch (placebo). All laboratory tests and
analyses of biopsy specimens were centrally performed at the
Università Politecnica delle Marche. Serum IgG class AGA and
IgA class anti-tTG were measured by standard enzyme-linked
immunoso
ent assay methods (Alfa-Gliatest and h-TTG; Euro-
spital Trieste, Trieste, Italy).
Small-bowel biopsies (�4 specimens from each procedure)
were taken from the second part of the duodenum. All biopsy
specimens were oriented and fixed in 10% formalin, embedded
in paraffin wax. The sections (5 �m) were stained with hema-
toxylin and eosin and immunostained by using anti-human CD3
antibody (DAKO, Glostrup, Denmark) to enhance diagnostic
accuracy in counting intraepithelial lymphocytes (IELs). Only
well-oriented sections were examined; when necessary, the sam-
ples were dissected again until they were of good quality. The
specimens were examined in batches by 2 pathologists with
long-standing experience in morphometric analysis (IB and
AM), who were blinded to subject assignment. The morphomet-
ic analysis of the sections was performed on �10 well-oriented