A new tool in the field of in-vitro diagnosis of allergy: preliminary results in the comparison of ImmunoCAP© 250 with the ImmunoCAP© ISAC

Background: The ImmunoCAP(C) ISAC allows for the determination of specific immunoglobulin E (IgE) against 103 recombinant or purified allergen components in a single analytical step. The aim of our study was to perform a comparison of the specific IgE results measured with the microarray method to those obtained using the traditional method of ImmunoCAP(C). Methods: We selected 86 clinically relevant patients on the basis of their specific IgE for recombinant allergens (ImmunoCAP(C) 250, Phadia). Also, we selected two patients with a high total IgE to evaluate the non-specific binding of IgE. All samples were screened with the ImmunoCAP(C) ISAC. Then, we compared the 555 specific IgE antibodies results provided by ImmunoCAP(C) ISAC with the specific IgE levels obtained with ImmunoCAP(C) 250. Results: We observed that 82 of the 384 results found to be positive with ImmunoCAP(C) were negative with ISAC(C) (concordance 78.65%). Of 171 negative results obtained with ImmunoCAP(C), 11 were positive with ISAC(C) (concordance 93.57%). No non-specific binding was observed. Conclusions: Our results show that the ImmunoCAP(C) ISAC has good analytical performance when compared with the ImmunoCAP(C) 250 method. We did not observe any nonspecific binding. However, better sensitivity for some clinically relevant allergen components, such as rPru p 3 is needed.