The establishment of a new method to detect food allergen specific IgE and its clinical application for detecting allergic diseases

Abstract

Objective To prepare a detective membrane strip for detection of food allergen-specific IgE in serum samples and estimate its clinical application value in allergic diseases. Methods The crude extracts of the food allergens were prepared. Nitrocellulose membrane as the solid support was selected and the coating and the detecting conditions were optimized. The membrane strips were used to detect serum samples in 210 patients with allergic diseases and the results were compared with German Allergy Screentesting system. Results The optima] experimental conditions were as follows: The NC membrane was adopted as the solid support. After being spotted, the food allergens were incubated for 2 hours at room temperature, followed by 2% PVA blocking for 1 hour. After serum samples were diluted (1: 10) and incubated for 2 hours at room temperature, the concentration of anti-human IgE was 2 μg/mL Compared with the German Allergy Screen-testing system, their positive detectical coincidence was 63.6%, and negative detectical coincidence was 94. 6%. The two methods had no difference in detecting the majority of food allergens such as egg white, milk, peanut, soybean, crab and shrimp (X2 2.53, 2.40, 2.08, 2.38, 0.17,1.13, P>0.05). Conclusions The advantages of our method for detecting allergic diseases are little serum needed, multiple detective allergens, simple manipulation and low cost. This method has obvious clinical application value, which should be a new detective method for the allergic diseases with broad perspectives. Key words: Food hypersensitivity; Immunoglobulin E