What is the recommended first test for a patient exhibiting symptoms of gluten intolerance?

The recommended first test for a patient exhibiting symptoms of gluten intolerance is the tissue transglutaminase antibody test, often abbreviated as tTG-IgA. This test is critical because it identifies the presence of antibodies against tissue transglutaminase, an enzyme that is involved in the gluten metabolism. Elevated levels of these antibodies are commonly associated with celiac disease, which is a form of gluten intolerance.

In clinical practice, the tTG-IgA test is preferred as an initial screening method due to its high sensitivity and specificity for celiac disease. If the test shows elevated antibodies, it may prompt further testing, including a small bowel biopsy to confirm damage to the small intestine and assess for celiac disease.

While other tests such as measuring deamidated gliadin peptide antibodies or checking for specific human leukocyte antigens can be helpful, they are generally not the first-line tests. The small bowel biopsy, while definitive for diagnosis, is invasive and not suitable as initial screening in most cases.

This systematic approach allows healthcare providers to adequately assess and manage patients suspected of having gluten-related disorders effectively.