Background: The aim of this study was to compare the technical and clinical effectiveness of two platforms (Phadia ImmunoCAP™ and Hycor NOVEOS) for the measurement of IgE specific for 10 food allergens. Methods: 289 patients, as part of allergy diagnosis or of their follow-up were included and tested for IgE specific for six food allergen extracts (egg white, cow’s milk, peanut, hazelnut, fish, shrimp) and four molecular allergens (Gal d 1, Bos d 8, Ara h 2, Cor a 14). Specific IgE measurements were carried out using the ImmunoCAP™ and NOVEOS methods. Food allergy diagnosis was established according to international guidelines. Results: A very good correlation (rho>0.9) was present between the two platforms, while specific IgE concentrations measured with NOVEOS were consistently lower (mean -15%) than with ImmunoCAP™. NOVEOS provided higher overall odd-ratios and relative risks for allergen extracts than ImmunoCAP™, but the difference was not significant. When all ten allergens were considered, NOVEOS provided better ROC curves (p=0.03) and thus, had a better ability to establish the true value. Finally, we found that the most discordant results were observed with hazelnut and peanut extracts, and were related to cross-reactive carbohydrate determinants on these two ImmunoCAP™. Conclusions: Specific IgE determination by either ImmunoCAP™ (odd-ratios of allergy = 25.1) or NOVEOS (odd-ratios of allergy = 33.0) is similarly highly informative on the risk of allergy in the selected population. The NOVEOS platform presents the advantage of being less affected by unwanted reactivity due to IgE specific for carbohydrate determinants, while requiring a ten-fold lower test sample volume.

Purpose of review Serum tryptase, a mast cell marker, provides clues for the mechanism, severity, and management of drug hypersensitivity induced by immunoglobulin E dependent or independent mast cell activation. Recent findings The interpretation of serum tryptase levels has been challenged during the last 2 years by major advances in tryptase genetics and their rapid incorporation into clinical practice. On the contrary, new pathophysiological insight into nonmast cell-dependent immediate hypersensitivity has been gained. Summary This review provides up-to-date information on the pathophysiology and recommended use and interpretation of tryptase in the context of drug hypersensitivity reactions as a function of their endotype.