Can a negative blood test for celiac be wrong?

Accuracy of the test most commonly used to diagnosis celiac disease called into question in new study. When the blood test most often used to diagnose celiac disease is negative, the result might not be accurate, according to a new study.

What if tTG IgA is negative means?

For individuals who test negative, IgA deficiency should be considered. If total IgA is normal and tissue transglutaminase (tTG)-IgA is negative, there is a low probability of the patient having celiac disease and a biopsy may not be necessary.

What can cause a false negative celiac test?

There are two recognized reasons for false negative blood tests for celiac disease: Patients with deficiency of one type of antibody, IgA (they are born that way) will have low endomysial antibodies and anti-tissue transglutaminase antibodies since they are IgA-type antibodies.

Can tTG IgA be false positive?

Conclusions: The results of the various methods of assaying anti-tTG antibodies in patients with LC are highly variable, and the positives found are generally false positives, partly due to the high immunoglobulin concentration.

How are transglutaminase antibody levels predict IgA deficiency?

Tissue transglutaminase antibody levels predict IgA deficiency Our data provide a simple means of avoiding unnecessary total IgA measurements in the assessment of coeliac disease.

Can a negative Iga test be a false negative?

However, given an increased prevalence of IgA deficiency among coeliac patients there is a risk of false negative results. Hence, in addition to specific serum tTG IgA, screening tests frequently include total IgA levels.

Can a positive TTG result be a sign of celiac disease?

The authors believe positive tTG IgG results, combined with negative IgA results, is evidence of IgA deficiency, and potentially of celiac disease. While the presence of IgG-tTG seems to be of limited diagnostic value in IgA-sufficient celiac patients, the presence of these antibodies without IgA-tTG might be a sign of IgA deficiency.

What causes a false negative blood test for celiac disease?

There are two recognized reasons for false negative blood tests for celiac disease: Patients with deficiency of one type of antibody, IgA (they are born that way) will have low endomysial antibodies and anti-tissue transglutaminase antibodies since they are IgA-type antibodies.