Analysis of candidate genes in celiac disease. A tool to identify life threatening associated genes?
D. Nuzzo, F. Cataldo, L. Scola, G.I. Forte, A. Crivello, A. Giacalone, S. Accomando, G. Candore, C. Caruso, D. Lio
Gruppo di Studio sull'Immunosenescenza, Dipartimento di Biopatologia e Metodologie Biomediche, Università di Palermo, Corso Tukory 211, 90134 Palermo
Given the clear role of gluten in causing autoimmunity, celiac disease
(CD) represents a unique example of an immune mediated disease for
which early diagnosis and dietary treatment can prevent its severe,
sometimes life threatening, complications. Patients with undiagnosed
and untreated CD, as well as those diagnosed later in life, have an
increased morbidity and mortality due to associated conditions. Since
CD is a multisystem disorder, these patients are at risk of chronic ill
health, permanent stunted growth, infertility, skeletal disorders, and
malignancy. Moreover, the mortality rate at every age is twofold
greater in untreated coeliacs. As well known, CD has a strong genetic
component, with a sibling relative risk of about 10-15%. The major
susceptibility locus is in Major Histocompatibility Complex (MHC)
encompassing the human leukocyte antigen ( HLA ), and the HLA alleles
DQA1*0501 and DQB1*0201 are strongly associated with CD. However,
haplotype sharing studies suggest that genes within the MHC complex
contribute no more than 40% to the risk for gluten intolerance. This
means that a CD genetic risk is also conferred by some other non-HLA
genes, and it has been suggested that some genes, encoding for the
pro-inflammatory cytokines and involved in the immunological mediated
lesions of CD, are associated with the risk for gluten intolerance. In
this paper are reported data on the evaluation, by a PCR-ARMS
technique, of a Transforming growth factor-beta2 (TGF-β2)
polymorphism association to celiac disease studying the
1249-1250InsACAA/Non-Ins genotype distribution in 88 CD patient 99 age
and sex matched control and 28 >95 years old healthy subjects living in
west-Sicily. TGF-β2, actually is involved both in the control of
inflammatory response, activating tissue remodelling, and in the
induction of IgA isotope switching in B cells. Considering these
functions, an increased TGF-2 production might be involved in
mucosal damage and IgA autoantibody production in CD subjects. Our data
demonstrate that, in spite of functional role of the cytokine, genotype
frequencies of CD patients are not different from that of age matched
and >95 years old healthy control groups. On the other hand, we have
recently reported that celiac patients show a pro-inflammatory cytokine
genetic profile characterized by the simultaneous presence of both the
tumour necrosis factor-alpha -308A and of the interferon-gamma +874T
allele positive genotypes. Both the two alleles are associated to an
increased production of the two major pro-inflammatory cytokines and it
is well known that an high pro-inflammatory profile is considered
detrimental for life span expectation facilitating rising of the major
aging associated disease (Cardiovascular diseases, Dementia,
Osteoporosis, Malignancy) that are considered among the major CD late
complications. Moreover a decrease of interferon-gamma +874T allele was
found associated to longevity in a group of centenarian woman. All
together these findings seem to suggest that the genotype profile
associated to CD susceptibility might be detrimental for long life
expectancy and studies on genetic asset of CD patients might enlighten
candidate gene for anti-ageing strategies.
Key words:
Celiac disease, longevity, TGF-beta2, centenarians
Problems or questions regarding this site should be directed to
the organiser