Purified oat protein may induce immune activation in coeliac disease

Intake of gluten-free oats appears to trigger acute dose-dependent immune and symptom responses, although they rarely lead to prolonged symptoms or intestinal damage, according to a study.

For the study, researchers recruited 33 adult patients with coeliac disease who were HLA-DQ2.5 positive and had been treated. These patients underwent a single-bolus or 6-week oat avenin or 3-month whole oats ingestion intervention.

T-cell activation following the intervention was assessed using serum interleukin 2 (IL-2). Symptom measures, intestinal histology, and immune studies on blood and duodenum were also performed.

A total of 29 participants were included in the analysis. Of these, 11 participants (38 percent) showed avenin-induced dose-dependent T-cell activation and 17 (59 percent) had acute symptoms. Of note, more severe symptoms correlated with higher levels of IL-2.

In a single highly symptomatic patient (3 percent), avenin induced vomiting and a striking pro-inflammatory cytokine profile similar to wheat-induced responses.

Additionally, avenin resulted in the augmented presence of CD38-expressing tetramer-positive, integrin β7-positive, T effector memory CD4-positive T cells in the blood. However, reductions in symptoms, IL-2 release, and tetramer frequency were observed following 6-week avenin intake. No cases of enteropathy were reported.

The findings suggest that a minority of individuals with coeliac disease may need to exclude oats from their diet.