Gluten-related disorders disease patients who have HLA-DQ2 and HLA-DQ8. Coeliac disease (American English: celiac) (CD) is one of the most common chronic, immune-mediated disorders, triggered by the eating of gluten, a mixture of proteins found in wheat, barley, rye and derivatives. Evidence has shown that this condition not only has an environmental component but a genetic one as well, due to strong associations of CD with the presence of HLA (Human leukocyte antigen) type II, specifically DQ2 and DQ8 alleles. These alleles can stimulate a T cell, mediated immune response against tissue transglutaminase (TTG), an enzyme in the extracellular matrix, leading to
Gluten "generally recognized as safe" (GRAS). In August 2013, the FDA issued a final ruling, effective August 2014, that defined the term "gluten-free" for voluntary use in the labeling of foods as meaning that the amount of gluten contained in the food is below 20 parts per million. Gluten Gluten (from Latin "gluten", "glue") is a composite of storage proteins termed prolamins and glutelins that is stored together with starch in the endosperm (which nourishes the embryonic plant during germination) of various cereal (grass) grains. It is found in wheat, barley, rye, oats and related species and hybrids (such as spelt,