A tissue transglutaminase IgA (tTg-IgA) test is used to help doctors diagnose celiac disease. In this autoimmune disorder, the immune system mistakenly thinks that gluten — a protein in wheat, barley, rye, and oats — is a foreign invader.

What is a tTG blood test?

A tissue transglutaminase IgA test or tTg-IgA test is an effective method used in the diagnosis of celiac disease. It is a blood test that checks for antibodies or immunoglobulins, which are proteins produced by the immune system. A high number of antibodies in blood indicate celiac disease

What happens if tTG is positive?

All celiac disease blood tests require that you be on a gluten-containing diet to be accurate. The tTG-IgA test will be positive in about 93% of patients with celiac disease who are on a gluten-containing diet. This refers to the test's sensitivity, which measures how correctly it identifies those with the disease.