Contact a healthcare professional (primary care, gastroenterologist, or dietitian) before starting a gluten-free diet
Continue eating gluten daily until testing is completed
Ask for blood tests:
tTG-IgA (tissue transglutaminase IgA)
Total serum IgA
If total IgA is low: tTG-IgG and/or DGP-IgG
Consider DGP-IgA/DGP-IgG in some cases
If blood tests are positive or symptoms are significant: request an upper endoscopy with small-bowel (duodenal) biopsies
Ask about HLA-DQ2 and HLA-DQ8 genetic testing if needed:
A negative result generally rules out celiac disease
Positive results do not confirm celiac disease
If already on a gluten-free diet: discuss a supervised gluten challenge and repeat testing with a clinician
Review medication and supplements with the clinician to ensure they do not interfere with interpretation
If results confirm celiac disease: follow medical guidance for baseline labs and monitoring (e.g., anemia, iron studies, vitamin levels)