Utility of Basophil Activation Test for monitoring the acquisition of clinical tolerance after oral desensitization to cow's milk: Pilot study.

OBJECTIVE: The quantification of basophil activation by flow cytometry is a useful tool for the assessment of immediate-type responses to food allergens and the prediction of clinical tolerance in food allergy patients. The aim of this study is to investigate how the analysis of allergen-induced CD63 up-regulation by flow cytometry can be effective in monitoring the acquisition of clinical tolerance by specific oral desensitization in food allergy. To our knowledge, this is the first study to examine this topic. MATERIALS AND METHODS: Three male patients affected by cow's milk allergy underwent successful oral desensitization to cow's milk. In order to monitor the acquired clinical tolerance that occurred after treatment, we performed laboratory tests for total and specific IgE, specific IgG4 and the Basophil Activation Test (BAT) both at baseline and at the end of the desensitization protocol. RESULTS: Using a fluorescent enzyme immunoassay, the comparison of specific cow's milk antibodies before and after treatment showed a decrease of specific IgE levels, without reaching normal values, and an increase of specific IgG4 levels. A complete suppression of cow's milk proteins (α-lactoalbumin, ß-lactoglobulin and casein) induced CD63 regulation was observed in all three reported cases. CONCLUSIONS: Using flow cytometry, food allergen-specific basophil responses could be monitored in order to identify an acquired tolerance induced by desensitization treatment. Although further studies are needed to develop this important new topic, it was interesting to note that the BAT seemed to be more sensitive and characterized by a close correlation with clinical tolerance.

'Empty sella syndrome': a case of a patient with sodium succinate hydrocortisone allergy.

OBJECTIVE: We present the case of a woman with 'empty sella syndrome' who experienced generalized urticaria after the administration of sodium succinate hydrocortisone in two episodes. METHODS: The patient underwent an allergological evaluation (prick, intradermal, and patch tests) with hydrocortisone sodium succinate, hydrocortisone acetate, hydrocortisone, hydrocortisone sodium phosphate, methylprednisolone hemisuccinate, methylprednisolone, and preservatives held in the formulation of sodium succinate hydrocortisone (sodium phosphate and methyl-p-oxybenzoate). The basophil activation test (BAT) was also performed with hydrocortisone. The single-blind i.m. challenge test was performed with hydrocortisone sodium phosphate in 4 days. RESULTS: Skin test with hydrocortisone sodium succinate and methylprednisolone hemisuccinate was positive. On the contrary, allergological tests performed with other formulations of the same steroids and preservatives were negative. These results showed an immediate-type allergy to succinate ester. BAT was not helpful to improve our diagnostic work-up because our patient was a 'nonresponder.' Therefore, the patient underwent successfully to a challenge test with hydrocortisone sodium phosphate. CONCLUSIONS: Patients with succinate ester allergy can tolerate alternative corticosteroids without ester.