primary prevention of coeliac disease - Associazione Italiana ...

70 MECHANISMS OF ORAL TOLERANCE
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intolerance is a central feature of the disorder . However, in the past, cases of possible
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transient gluten sensitivity were described . Is it possible that this phenomenon of
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transiency is more common than currently appreciated? .
The events that happen to pediatric cases of CD, when they reach adolescence, may
be informative concerning the permanency of gluten intolerance. Detailed information
about these events is absent. Nonetheless, it is recognized that many children adhere
less well to a strict gluten free diet when they reach adolescence. This may represent the
general “rebellion” of teenagers! Despite eating gluten containing foods, few
symptoms may develop. This in turn may lead to increasing carelessness about their
diets. Some of these patients eventually have intestinal biopsies performed and the
mucosa can appear surprisingly normal or even completely normal. Doubts about the
accuracy of the initial diagnosis of CD may then be raised. Some of these patients are
then given a gluten challenge and it is reported that it can take many months or even
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years for histological evidence of CD to return . This contrasts with gluten challenge
in patients with an adult diagnosis of CD when symptomatic and histological evidence
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of disease relapse often only requires one or two months of gluten intake .
Although categorical data about adolescent remission of CD is lacking, the
information available strongly suggests that this really does occur. If this is the case, it
may indicate that restoration of tolerance to gluten is possible. The majority, if not all of
these patients, eventually develop symptomatic gluten intolerance in adulthood,
demonstrating the essential permanency of CD. However, it is possible that
investigation of adolescent CD patients, during their period of remission, may give
insight to T cell tolerance mechanisms towards gluten.
Conclusions
The gut mucosal immune response to the majority of food and other antigens is
typically of low intensity and remains confined to the local environment. The term ²oral
tolerance²may be applied to this controlled immune response. However, in the case of a
single food type, gluten, an enhanced T cell immune response develops in a substantial
number of individuals and features of coeliac disease develop. In this disorder, immune
tolerance of gluten is apparently lost. With an improved understanding of the
mechanisms of oral tolerance, it is possible that manipulation of the immune response
to gluten in coeliac patients could restore the normal physiological state of low
reactivity to this food antigen. This would remove the requirement of gluten-free diet
treatment of coeliac disease.
References
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coeliac iceberg in Italy. A multicentre antigliadin antibodies screening for coeliac
disease in school-age subjects. Acta Paediatr Suppl 1996; 412: 29-35.
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