Aetiology

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