Simtomax point-of-care test effective for differentiating between celiac disease, nonceliac gluten sensitivity

Among three point-of-care tests for celiac disease, Simtomax was the most accurate for distinguishing between celiac disease and nonceliac gluten sensitivity, according to data presented at the British Society of Gastroenterology Annual Meeting.

“Thirteen percent of the general population self-report intolerance to gluten, and the prevalence of nonceliac gluten sensitivity (NCGS) is estimated to be much higher than celiac disease,” Michelle Lau, MbChB, MRCP, clinical research fellow in the academic department of gastroenterology at Royal Hallamshire Hospital, Sheffield, U.K., told Healio Gastroenterology. “The symptoms of celiac disease and NCGS can be indistinguishable, but patients with celiac disease carry the risk of complications if left untreated. Our aim was to evaluate the role of Simtomax in differentiating between celiac disease and NCGS.”

Michelle Lau

To determine the utility of the immunoglobulin A/G deamidated gliadin peptide-based point-of-care test Simtomax (Tillotts) in discriminating between celiac disease and NCGS, Lau and colleagues compared the accuracy of three point-of-care tests in three prospectively recruited patient groups.

The first group included 100 patients with a positive endomysial antibody (EMA) referred for gastroscopy, all of whom were tested with Simtomax, Biocard (IgA-tissue transglutaminase [TTG], Ani Biotech) and Celiac Quick Test (IgA/G/M-TTG, Biohit).

To test the sensitivity of Simtomax in the general population, the second group included 667 patients with GI symptoms who also underwent gastroscopy and were tested with Simtomax, EMA and TTG. Patients with positive EMA, previous villous atrophy, known celiac disease, self-reported gluten sensitivity and those on a gluten-free diet were excluded from this group to reduce positive ascertainment bias.

Finally, to test the sensitivity of Simtomax in a gluten sensitive population, the third group included 35 patients with self-reported gluten sensitivity who also underwent gastroscopy and were tested with Simtomax, EMA and TTG.

All sensitivities were measured based on histology results from five duodenal biopsies.

The first group showed Simtomax was superior to the other point-of-care tests for detecting celiac disease (96.5% sensitivity; 85% celiac disease prevalence). The second group showed Simtomax had comparable sensitivity and negative predictive value to EMA and TTG, with a celiac disease prevalence of 4.95%. Finally, the third group showed Simtomax had 100% sensitivity in identifying celiac disease in patients with self-reported gluten sensitivity, and a 100% negative predictive value for identifying patients with NCGS.

“To our knowledge, this is the first study to demonstrate that Simtomax had 100% sensitivity and NPV for celiac disease in a gluten sensitive population, which suggests that Simtomax can effectively rule out celiac disease in patients who self-report gluten intolerance,” Lau said. “Larger studies are required to further validate the results.” – by Adam Leitenberger

References:

Lau MS, et al. Abstract #OC-024. Presented at: British Society of Gastroenterology Annual Meeting; June 20-23, 2016; Liverpool, UK.

Disclosures: One of the researchers reports grant/research support from Tillotts Pharma, which did not have any input in the study design, access to study data, interpretation of findings or drafting of the manuscript.

Editor's note: This article was updated on June 24 with additional comments from the presenter.