Eosinophil-derived proteins in postprandial (food-dependent) exercise-induced anaphylaxis.

BACKGROUND

Postprandial exercise-induced anaphylaxis (PPEIAn) is a form of EIAn in which the ingestion of food before the exercise is associated with the onset of symptoms. Skin reactivity and the presence of specific serum IgE to several food allergens suggest the occurrence of food-dependent allergic mechanisms.

METHODS

In order to study the involvement of eosinophils in the pathogenesis of PPEIAn we measured the changes in serum eosinophil cationic protein (ECP) and eosinophil protein X/eosinophil-derived neurotoxin (EPX/EDN) levels in 6 patients with PPEIAn, subjected to three separate challenges with either suspected foods only, exercise after a meal without or with suspected food ingestion.

RESULTS

We found serum levels of both eosinophil-derived proteins increased only in challenges including both exercise and suspected food ingestion. Symptoms of anaphylaxis occurred in 3 of these patients.

CONCLUSIONS

The increased release of eosinophil basic proteins in PPEIAn patients, caused by physical exercise following ingestion of suspected foods, is not obligatory for the definition of the syndrome.