Non-celiac gluten sensitivity not yet universally adopted. For people on a gluten-free diet who are unable to perform an oral gluten challenge, an alternative to identify possible celiac disease is an in vitro gliadin challenge of small bowel biopsies; this test is only available at selected specialized tertiary-care centers. After exclusion of celiac disease and wheat allergy, the subsequent step for diagnosis and treatment of NCGS is to start a strict gluten-free diet (GFD) to assess if symptoms improve or resolve completely. This may occur within days to weeks of starting a GFD, but improvement may also be due to a non-specific, placebo
Gluten immunochemistry include: LTP (albumin/globulin), thioredoxin-hB, and wheat flour peroxidase. A particular 5 residue peptide, Gln-Gln-Gln-Pro-Pro motif, has been found to be a major wheat allergen. New immunogenic motifs appear in the literature almost monthly and new gliadin and "Triticeae" protein sequences appear that contain these motifs. The HLA DQ2.5 restricted peptide "I I Q P Q Q P A Q" produced approximately 50 hits of identical sequences in NCBI-Blast search is one of a several dozen known motifs whereas only a small fraction of Triticeae gluten variants have been examined. For this reason the immunochemistry is best discussed at the level