Coeliac disease may be triggered by gluten in barley and rye with a distinct immunogenic profile from that of wheat gluten proteins, Australian researchers have shown.

In research that may have implications for the development of immune therapies for coeliac disease, Victorian researchers have shown that barley and rye-derived gluten triggers activation of pathogenic CD4+ T cells that are central to Coeliac Disease  pathogenesis.

But the barley and rye T-cell-activating peptides were different to those of wheat gluten peptides.

While most research into CD has focused on the role of wheat gliadin on the immune activation and gut toxicity, researchers at the Walter and Eliza Hall Institute of Medical Research, Melbourne conducted a barley and rye feeding study in 42 children with human leucocyte antigen (HLA)-DQ2.5+.

After consuming barley or rye for three days, adverse symptoms (predominantly gastrointestinal) were reported in 91% (38/42) of children.

Immune activation of hordein or secalin-specific T-cells was observed in in 62% (26/42) of the children. However the adverse clinical symptoms correlated poorly with the presence or magnitude of T-cell responses.

Writing in the journal Gut, the researchers said the contribution of T-cell populations targeting unique hordein and secalin sequences in barley and rye, independent of wheat, to Coeliac Disease pathogenesis, should not be underestimated.

They noted that barley was a common component of a child’s diet in the form of malted drinks, for example, Milo, Ovaltine and Vegemite, whereas rye-containing foods are uncommon.

“The findings are highly relevant for immunotherapies that aim to target the complete T-cell response to wheat, barley and rye,” they wrote.

“Design of novel immune treatment strategies for children and adults with Coeliac Disease  need to consider the important pathogenic contribution from unique barley and rye sequences independently of wheat.”