Celiac Disease Occurs When an Individual Makes an Aberrant Immune $\alpha$

Celiac disease occurs when an individual makes an aberrant immune response to a protein in gluten, such as $\alpha$ -gliadin. Evidence suggests that very few proteins are able to elicit the immune response that causes celiac disease. A key piece of this evidence is that:

A) All patients with celiac disease make IgA antibodies to transglutaminase.
B) Gliadin-derived peptides stimulate epithelial cells to produce IL-15.
C) Innate immune responses to gluten induce up-regulation of MIC-A on epithelial cells.
D) More than 95% of patients express the MHC class II DQ2 allele.
E) Monozygotic twins show an 80% concordance for developing celiac disease.