Celiac disease is typically diagnosed through a combination of blood tests and a biopsy of the small intestine. Key diagnostic steps include:
- Blood Tests: These tests check for specific antibodies associated with celiac disease, such as anti-tissue transglutaminase (tTG) antibodies and anti-endomysial antibodies (EMA). Elevated levels of these antibodies suggest an immune response to gluten.
- Genetic Testing: While not used for diagnosis alone, genetic testing can identify certain genes (HLA-DQ2 and HLA-DQ8) that predispose individuals to celiac disease.
- Small Intestine Biopsy: If blood tests are positive, a biopsy of the small intestine is usually performed during an endoscopy. This biopsy examines the villi to check for damage or flattening, which is characteristic of celiac disease. It’s important to continue eating gluten before testing to ensure accurate results, as removing gluten from the diet before testing can lead to false-negative results.