The DNA Connexions Gluten Intolerance test utilizes cheek cells to detect the presence or absence of the HLA tissue typing markers for DQ2 and DQ8 (actually the markers HLA-DQB1*02, HLA-DQA1*0501, HLA-DQB1*0302 exon2 and HLA-DQB1*0302 exon3). The presence of any of these genetic markers is 95% predictive for gluten intolerance/sensitivity. The presence of both markers is 95% predictive for coeliac disease.
This test can determine whether or not you are at risk for gluten intolerance/sensitivity or coeliac disease before symptoms occur.
Gluten sensitivity is a condition with symptoms similar to those of Celiac disease that improve when gluten is eliminated from the diet. People with gluten sensitivity can experience symptoms such as "foggy mind", depression, ADHD-like behavior, abdominal pain, bloating, diarrhea, constipation, headaches, joint pain, and chronic fatigue when they have gluten in their diet, but other symptoms are also possible. Examples may include asthma-like symptoms upon ingestion of gluten, and/or a filling of the sinus cavities with fluid. While these are common symptoms of Celiac disease, these individuals do not test positive for Celiac disease and/or a wheat allergy.
Individuals who have been diagnosed with gluten sensitivity do not experience the small intestine damage or develop the tissue transglutaminase (tTG) autoantibodies found in celiac disease. Triggers such as viruses, bacteria and possibly gluten itself activate professional antigen-presenting cells, such as dendritic cells (DCs), and epithelial cells. Antigen-presenting cells mature in response to interleukin-15 (IL-15) and type I interferon (IFN) produced by stressed epithelial cells, and acquire pro-inflammatory properties; after migration to the draining Peyer's patch or mesenteric lymph node (MLN), mature DCs present gluten to induce the activation of gluten-specific HLA-DQ2- or HLA-DQ8-restricted CD4+ T cells. Transglutaminase 2 (TG2) and gluten form complexes, which TG2-specific autoreactive B cells can internalize and consequently present gluten peptides on HLA-DQ2 or HLA-DQ8 at their surface.