Comparative Study of ImmunoCAP and ELISA for Detecting Allergen Specific IgE to Japanese Hop Pollen and Two Spotted Spider Mite

Abstract

Background & Objectives: Japanese hop pollen (Hop J) and two spotted spider mite (TSM) are common allergens in this country. The aim of this study was to validate a new immunoCAP test for detecting allergen-specific IgE to Hop J and TSM compared to skin reactivity and ELISA results. Methods: Ninty-five allergy patients showing more than 2+ response on skin prick test to Hop J, 131 allergy patients showing more than 2+ response on skin prick test to TSM and 60 non-atopic healthy controls were enrolled. Skin prick testing was performed using homemade Hop J pollen and TSM extracts. The specific IgE levels to both homemade allergens were measured by ELISA, which were compared to those of the immunoCAP system. Results: The positive rates of serum specific IgE to Hop J were 57% by ELISA and 51% by Pharmacia immunoCAP system among 95 patients tested. The positive rates of serum specific IgE to TSM were 28% by ELISA and 50% by immunoCAP system among 131 patients tested. A significant correlation was found in specific IgE level between ELISA and the immunoCAP system (r=0.63 for Hop J and r=0.61 for TSM, P<0.05). Conclusion: The new immunoCAP system for detecting serum specific IgE antibodies to Hop J pollen was comparable to the results of other in vivo and in vitro test and can be applied for the diagnosis of Hop J-allergic patients. New immunoCAP system to TSM was superior to the ELISA test, and can be used for screening TSM-sensitive patients.