Study of the in vitro sulphidoleukotriene production in food-allergic patients

Objective and design: To study in vitro sulphidoleukotriene (sLT) production by food allergic patients using cellular allergen stimulation test (CAST)-ELISA and to evaluate the reliability of this technique for diagnosing food allergic reactions. Subjects: Forty patients with adverse reactions after food intake, 20 healthy controls, and 15 individuals sensitized to inhalant allergens as atopic controls. Methods: Skin tests, serum-specific IgE, histamine release test (HRT), CAST-ELISA and food challenges. One-way ANOVA was used to compare tests results between patients and controls and to study mediator release and specific IgE, related to the severity of clinical pictures. Sensitivity and specificity were analyzed by ROC curves. Results: Food allergic patients showed higher (p < 0.05) Ag-dependent sLT production (836.2 +/- 664.1 pg/ml) (mean +/- standard deviation) than both control groups. After stimulus with anti-IgE antibodies, sLT production was higher (p < 0.05) by atopic controls (1630.8 +/- 696.5 pg/ml) compared to patients and healthy controls. Patients with anaphylactic reactions showed higher Ag-specific and anti-IgE sLT and histamine production than patients with less severe manifestations. Mean serum-specific IgE was significantly lower (p < 0.05) in patients presenting oral allergy syndrome compared to patients with more severe clinical pictures. CAST-ELISA was the most sensitive method, Prick by prick test was the most specific. Conclusions: CAST-ELISA may provide a useful tool for diagnosing food allergy. Enhanced cell releasability may be linked to-the severity of the clinical response to foods.