Question 1

Do I need to be eating gluten before this test?

Accepted Answer

Yes, it's essential to continue eating gluten-containing foods before testing. Gluten avoidance can cause antibody levels to decrease within weeks, potentially leading to false-negative results. Most experts recommend consuming gluten daily for at least 6-8 weeks prior to testing for optimal accuracy.

Question 2

What happens if I have IgA deficiency?

Accepted Answer

If your total IgA is low or deficient, the tTG-IgA test may not be reliable. In such cases, additional testing with IgG-based antibodies (like tTG-IgG or deamidated gliadin IgG) may be recommended to accurately screen for celiac disease. IgA deficiency affects 2-3% of people with celiac disease.

Question 3

Can this test definitively diagnose celiac disease?

Accepted Answer

While highly accurate, blood tests alone typically cannot provide a definitive celiac disease diagnosis. Positive antibody results usually require confirmation through intestinal biopsy or, in some cases, genetic testing. However, very high tTG-IgA levels (10+ times normal) combined with symptoms may be sufficient for diagnosis in some situations.

Question 4

How long after starting a gluten-free diet do antibody levels normalize?

Accepted Answer

Antibody levels typically begin to decline within weeks to months of starting a strict gluten-free diet. Complete normalization may take 6 months to 2 years, depending on individual factors and adherence to the diet. This is why testing must be done while still consuming gluten for accurate results.

Question 5

Are there other conditions that can cause positive results?

Accepted Answer

While tTG-IgA is highly specific for celiac disease, occasionally other autoimmune conditions like type 1 diabetes, autoimmune thyroid disease, or liver disease may cause mild elevations. However, significantly elevated levels are typically associated with celiac disease, especially when accompanied by appropriate symptoms.

Question 6

Is this test accurate in children?

Accepted Answer

Yes, the tTG-IgA test is generally accurate in children over age 2-3 years, provided they have been consuming gluten-containing foods. For very young children (under 2 years), additional tests like deamidated gliadin peptide antibodies may be needed, as the immune response to gluten may not be fully developed.

Celiac Disease Panel (tTG-IgA + Total IgA)