A test that may best biopsy in detecting celiac disease

Last Updated: 2017-08-16

By Reuters Staff

NEW YORK (Reuters Health) - The HLA-DQ:gluten tetramer test is better than biopsy for detecting celiac disease after 14-day gluten challenge in people who have been adhering to a gluten-free diet, researchers from Norway report.

Many people follow gluten-free diets without being diagnosed with celiac disease, thereby significantly complicating the diagnosis using current tests, which lack adequate sensitivity in people who do not eat gluten.

Dr. Vikas K. Sarna and colleagues from Oslo University Hospital and University of Oslo, in Norway, investigated whether the currently recommended 14-day gluten challenge was enough to induce villous blunting in patients known to have celiac disease and whether the HLA-DQ:gluten test or other tests could improve the celiac disease detection rate earlier in the gluten challenge.

Among 19 adults with celiac disease, only 5 developed biopsy-detectable villous blunting (Marsh type 3), whereas the rest of the biopsies remained negative for celiac disease, according to the August 4 online report in Gut.

Twelve patients experienced at least a 50% increase in intraepithelial lymphocyte counts, and 9 of the 12 also had significant decreases in the ratio of villous height to crypt depth.

Anti-transglutaminase 2 immunoglobulin A levels remained low 28 days after the start of gluten challenge, but 3 cytokines (interleukin-8, interferon-gamma inducible protein, and eotaxin) showed significantly increased concentrations within 6 hours after gluten challenge.

The median number of HLA-DQ:gluten tetramer cells increased from 4.2 at baseline to 22.9 on day 6 of the gluten challenge, with 12 of 15 participants showing a significant response (data from 4 participants were not available for technical reasons).

"Our results clearly demonstrate that the gluten-specific T-cell response in blood on day 6 is a sensitive and fast reacting parameter for gluten exposure in celiac disease," the researchers note. "Based on previous results, a 3-day challenge, and not continuous challenge in 6 days as was done in the current protocol, should suffice. If undertaking a gluten challenge as part of the work-up, this 3-day challenge monitored by a near to non-invasive HLA-DQ:gluten tetramer test should represent an attractive option for patients and clinicians alike."

"Increased level of HLA-DQ:gluten tetramer appears to be a marker of celiac disease regardless of dietary regime as all, except one, of our participants with biopsy-proven celiac disease had detectable levels at baseline," they add.

"Aiming for a diagnostic work-up that is based on a short-duration gluten challenge, the less invasive blood test - based on HLA-DQ:gluten tetramers in a flow cytometric assay - seems to be a sensitive biomarker that should be explored further," the researchers conclude.

Dr. Sarna did not respond to a request for comment.

SOURCE: http://bit.ly/2vUcyRK

Gut 2017.