Celiac.com 11/03/2008 - Blood testing for radioimmunoassay (RIA) tissue transglutaminase auto-antibodies (tTG-Abs) has proven to be a sensitive test for celiac disease follow-up. Recent studies have shown that RIA can accurately detect tTG-Abs in human saliva. However, not much is known about reliability of this method for monitoring the progress of celiac disease over time in patients who are attempting to follow a gluten-free diet.
A team of researchers recently set out to assess salivary RIA tTG-Abs in celiac children on gluten-free diet. The research team included doctors M. Bonamico, R. Nenna, R.P.L. Luparia, C. Perricone, M. Montuori, F. Lucantoni, A. Castronovo, S. Mura; A. Turchetti, P. Strappini, and C. Tiberti.
The research team also included two control groups matched for age and sex. Group 3 included 89 gastroenterological patients, while group 4 included 49 healthy subjects. The team used RIA to detect tTG-Abs in saliva and blood, and compared the results against two other established tests: serum tTG-Abs ELISA and IgA anti-endomysium antibodies (EMA).
The team detected salivary RIA tTG-Abs in 94.5% of patients from group 1, 66.7% of celiac patients from group 2a, and 50.0% from 2b. They detected blood RIA tTG-Abs in 98.2% of patients from group 1, 72.2% of celiac patients from group 2a, and 50.0% from 2b. The longer patients were on a gluten-free diet, the more the tTG-Abs decreased. The research team also found a correlation between saliva and serum levels (r = 0.75, P = 0.0001). A celiac disease follow-up showed comparable salivary and serum RIA sensitivities, and higher levels for EMA and ELISA methods.
The research team concluded that it is possible to measure salivary tTG-Abs with a high level of accuracy; both at initial diagnosis for celiac disease, and also while patients are following a gluten-free diet.
This discovery means that doctors treating people with celiac disease might soon be able to use a simple saliva test to monitor the progress of their patients’ gluten-free diets. Such a development might take remove much of the guesswork for celiacs who are trying to follow a gluten-free diet, and would be particularly useful for patients who might be asymptomatic, or who are at risk for celiac-associated conditions.
Aliment Pharmacol Ther. 2008; 28(3): 364-370.