Variations of cationic proteins from eosinophil leukocytes in food intolerance and allergic rhinitis.

Challenge tests were performed in patients with food intolerance and allergic rhinitis to evaluate the usefulness of measurement of the eosinophil cationic protein (ECP) of serum to distinguish different allergic reactions. In one group of patients with food intolerance symptom-induced challenge resulted in a marked decrease of serum-ECP. The number of blood eosinophils decreased simultaneously in some but not all of these patients. In another group of patients with food intolerance serum-ECP displayed peak-like increases followed by a decrease. The decrease in serum-ECP may reflect that consumption of ECP is a result of idiosyncrasy in the target organ. In allergic rhinitis some patients showed an initial peak-like increase of serum-ECP, which was abolished by pretreatment with disodium-cromoglycate but not by pretreatment with antihistamine. Similar results have previously been demonstrated for allergic asthma. The difference obtained in serum-ECP upon challenge in typical reagin-mediated allergy and food intolerance may indicate that the latter is not reagin-mediated. However, the interpretation of data is difficult because of lack of knowledge regarding the turnover in the circulation of ECP.