Researchers Devise a Reliable Test for Wheat-Dependent Exercise-Induced Anaphylaxis

Researchers from Germany believe they have improved upon current methods for diagnosing wheat-dependent exercise-induced anaphylaxis (WDEIA) - and demonstrated that the condition isn't necessarily induced by exercise.

Researchers from Germany believe they have improved upon current methods for diagnosing wheat-dependent exercise-induced anaphylaxis (WDEIA) — and demonstrated that the condition isn’t necessarily induced by exercise.

The authors of the new study, which appears in The Journal of Allergy and Clinical Immunology, found 34 patients with a clear history of WDEIA.

Nearly half of those patients (8 male and 8 female; aged 23 to 76) underwent prospective oral challenge tests with gluten and, in many cases, with either exercise or a mixture of acetylsalicylic acid and alcohol, 2 “cofactors” that can augment allergic reactions to the point of anaphylaxis.

The researchers were able to confirm WDEIA in all 16 subjects — including 4 who had tested negative on all previous wheat challenges — by using either higher gluten doses or some combination of cofactors.

If the test demonstrates that level of accuracy in larger trials, it will prove significantly better than current diagnostic tools.

“Confirmation of WDEIA is challenging,” the study authors wrote. “Results of skin tests and measurement of specific IgE to wheat might be negative, probably because of the low concentration of the responsible peptide in wheat flour… [And] challenge test results with wheat and exercise often are negative in patients with WDEIA despite a clear history.”

Indeed, the authors went on to note, the most common test for WDEIA right now appears to be a challenge that combines wheat and exercise, but that challenge typically produces positive results in roughly a third of all people who actually have experienced WDEIA.

The results of the current study indicate that pure gluten may be a better material for challenge tests. Gluten alone produced reactions in 4 of the 16 patients, even though none of them had ever experienced any previous reaction without both wheat and exercise.

Several factors may explain why pure gluten produces more reaction that wheat flour, but the most important is probably its concentration. Among the subjects who responded to gluten alone, allergy-triggering quantities ranged from a low of 10g to a high of 80g, which is roughly the amount of gluten found in 2 pounds of bread.

Turning to co-factors, the study authors noted that exercise appears less able to induce “exercise-induced” anaphylaxis than other co-factors. A trio of patient who demonstrated no reaction to large quantities of gluten and moderate exercise exhibited symptoms soon after receiving aspirin and alcohol.

Previous research has failed to establish exactly why exercise can intensify the effects of allergens. The authors of the new study found no definitive answers, but they did find some evidence that conflicts with some existing theories.

“It has been suggested that acetylsalicylic acid had a direct effect on mast cell activation because of increased skin prick test reactions to wheat after acetylsalicylic acid treatment; we could not confirm this finding when skin testing with gluten after acetylsalicylic acid ingestion,” they wrote.

Also, “Increased gastrointestinal permeability has been widely discussed as a mechanism for cofactor-triggered food allergy. Our patients with WDEIA did not have increased baseline permeability.”

The study authors noted several limitations to their work, particularly its size, but they asserted that their results demonstrate that WDEIA is poorly understood and even more poorly named.

“Gluten-induced anaphylaxis currently described as ‘food (or wheat)-dependent exercise-induced anaphylaxis’ is not necessarily exercise induced and does not have to result in anaphylaxis,” they wrote. “Thus ‘augmentation factor—triggered food allergy’ might be a more appropriate term for this disease entity.”