aetiology
Last reviewed 01/2018
Pathogenetic factors include:
- diet:
- exposure to "prolamins", proteins rich in proline and glutamine
- the most common cause is hypersensitivity to wheat gliadin; often the peptide corresponding to residues 31-47 is responsible
- similarly antigenic proteins are found in barley, oats and rye
- HLA type:
- affected individuals show an increased frequency of histocompatibility antigens, A1, B8, and of haplotypes D3/DQw2 and D7/DQw2
- a specific HLA DQ heterodimer is particularly closely linked to coeliac disease (A1*D0501 with B1*0201)
- familial:
- 70% concordance in monozygotic twins
- 30% concordance in dizygotic twins who are HLA identical
- 5-19% incidence in first degree relatives
- time of first exposure to gluten:
- early exposure may be a risk factor for coeliac disease
- gluten should be avoided in the first six months of life
- viral infection may trigger coeliac disease e.g. gluten shares sequence similarity with adenovirus 12
- the autoantigen responsible for the anti-endomysial antibody activity is the enzyme transglutaminase