1. Gluten-related immunity and small-intestinal injury

In celiac disease, gluten from wheat, barley and rye triggers an abnormal immune response that damages the small intestine. Intestinal injury can impair nutrient absorption. Digestive discomfort or a change after eating a particular food cannot by itself establish the diagnosis. NIDDK’s diagnostic guide places symptoms alongside history and test findings.

2. Why TG2 and HLA are not a personal diagnostic result

A 2024 Nature Immunology study by Dotsenko and colleagues describes TG2-mediated deamidation of selected glutamine residues in gluten peptides. The modified peptides are presented through HLA-DQ2/DQ8, contributing to gluten-specific CD4+ T-cell responses and mucosal injury including villous atrophy. This does not establish one obligatory barrier-leak route or an identical injury stage in every person.

The study analyzed biopsies from diagnosed patients in a drug/gluten-challenge study; it is not a symptom-based test or a prediction of an individual’s treatment response. NIDDK notes that most people carrying DQ2/DQ8 variants do not develop celiac disease. Genetic susceptibility, antibody findings and actual mucosal findings are distinct pieces of information.

3. Discuss dietary changes before testing

NIDDK describes blood tests and small-intestinal biopsies as common diagnostic tools and advises against starting a gluten-free diet before testing because it can affect results. If you have already reduced or stopped gluten, report when and what changed. Ask for a preparation plan rather than setting your own gluten reintroduction amount or duration. Which tests are appropriate depends on individual circumstances and local clinical practice.

4. Diet and follow-up after diagnosis

NIDDK’s treatment information describes a gluten-free diet supported by a dietitian’s help with labels and meal planning. Ongoing management after diagnosis differs from starting an exclusion diet before evaluation. Ask about nutritional assessment, supplementation if needed and follow-up. Symptom improvement alone does not establish villous recovery; follow-up can include antibodies and, in some patients, further biopsies.

For persistent symptoms, take a food record to the clinician or dietitian. Gluten exposure and other conditions can have different implications; do not respond by repeatedly expanding restrictions or adding supplements yourself.

5. Prepare a record for the consultation

Record “symptoms, onset and frequency / observed changes such as weight / grains and products currently eaten / date and details of gluten reduction / confirmed family history / prior blood-test or biopsy reports and diet at testing / medicines and supplements / questions about test preparation.” Unknown results remain pending until the report is available.

A fictional entry, “bloating; reduced bread from October1; antibody testing not yet done; family history unknown,” helps communicate a dietary change and ask how to prepare. It does not diagnose celiac disease or prove gluten caused symptoms. Add actual test dates, findings and clinical interpretation as they become available.