Tissue transglutaminase autoantibody detection in human saliva: a powerful method for celiac disease screening

Objective To test the possibility of detecting tissue transglutaminase autoantibodies (tTG-Abs) in saliva with a novel sensitive fluid-phase radioimmunoassay (RIA). Study design Paired saliva and serum samples from 39 patients with celiac disease (CD), at the first biopsy (Group 1: 28 females, mean age 11.5 ± 11.1 years); 32 controls with a normal duodenal mucosa (Group 2: 18 females, mean age 8.1 ± 3.6 years); and 32 healthy volunteers (Group 3: 21 females, mean age 31.7 ± 9.8 years) were studied for tTG-Ab presence. Limit of positivity for salivary assay was calculated according to the 99th percentiles of Group 2 control children and was expressed as an autoantibody (Ab) index. Results Salivary tTG-Abs were found in 97.4% of the patients with CD and in 100% of the corresponding serum samples. All Group 3 subjects were negative with both saliva and serum assays. A correlation between saliva and serum tTG-Ab titers was found (r = 0.826, P = .0014). Conclusions This study demonstrates that it is possible to detect salivary tTG-Abs in CD with a non-invasive, simple to perform, reproducible and sensitive method.