Celiac.com 02/24/2012 - Currently, testing for anti tissue-transglutaminase antibodies is the standard of celiac disease blood testing. The test has a high sensitivity in patients who are eating a diet that contains gluten, but poor sensitivity for people on a gluten-free diet. So, it's not much use for measuring gluten-free diet success in people with celiac disease.
A research team set out to determine if a new test might be more useful than current standard in assessing long-term gluten exposure in celiac disease patients attempting to follow a gluten-free diet. The new test measures Immunoglobulin-A antibodies to catalytically active open conformation tissue-transglutaminase.
The study team included K. Pallav, D. A. Leffler, M. Bennett, S. Tariq, H. Xu, T. Kabbani, A. C. Moss, M. Dennis, C. P. Kelly, D. Schuppan. They are affiliated with the Celiac Center of the Beth Israel Deaconess Medical Center at Harvard Medical School in Boston.
The team made a preliminary dietary assessment of 147 patients with celiac disease, and grouped them according to good or poor compliance to a gluten-free diet. The team used 50 patients with inflammatory bowel disease as a control group.
The team then measured both open (new test) and closed (conventional) tissue-transglutaminase levels using standard enzyme linked immunosorbent assay.
The team's initial dietary review indicated that 128 of the celiac patients had followed a gluten free diet for more than six months. They found 19 to have poor compliance to a gluten-free diet.
Of the 19 who had poor adherence to a gluten-free diet, the team found 13 patients (68.4%) who tested positive using open conformation assay (p=0.51), while ten of the 19 patients (52.6%) tested positive using conventional assay (p=0.51). In the control group, just two patients tested positive using closed assay, while one tested positive using open assay.
The team concluded that, compared to conventional testing, open conformation tissue-transglutaminase may offer greater sensitivity in the poor gluten-free diet adherence group and higher specificity in the control population.
The team suggests studies on larger populations to determine whether open conformation tissue-transglutaminase assay may be superior to the conventional assay in measuring compliance with a gluten-free diet.Source: