The test detects the genes (human leukocyte antigens or HLA) that control the immune system's reaction to gluten. There are several types of HLA genes within each person and it is HLA-DQ that is most useful in the assessment of the probability that a person may be gluten sensitive. The reason gene testing assesses probability rather than disease itself is because some people have the genes for gluten sensitivity but have no detectable evidence of the immune reaction to gluten or have no symptoms. In such people, gluten sensitivity is still possible but the probability is lower than in a person who may be having symptoms attributable to gluten or that has antibodies detected.
HLA testing is most useful when there is diagnostic confusion about whether or not a person is gluten sensitive. Such confusion often stems from one of the following: atypical intestinal biopsy results, the presence of associated diseases (such as microscopic colitis) that may mask the expected improvement of symptoms when gluten is withdrawn from the diet, negative tests for gluten antibodies in the midst of suggestive symptoms or signs of gluten sensitivity or coeliac disease, or when there are no symptoms at all and the person or the doctor can hardly believe that gluten sensitivity is really present. Other situations HLA testing is useful is when a person is already on a gluten-free diet and for testing family members (particularly children) for the probability that they have or will develop gluten sensitivity.
The test utilises stool rather than blood as the testing substrate for food sensitivity; the rationale is that immunologic reactions to proteins in the diet that cause these reactions are centred within the intestinal tract and not in the blood.
- Abdominal pain
- Indigestion, heartburn
- Bloating, wind
- Brain fog
- Joint pain