Stability of specific IgE antibodies to common food and inhalant allergens

Abstract

Objective: To determine the optimum storage temperature for serum allergen specific IgE antibodies (sIgE) to common food and inhalant allergens.

Methods: Patient sera with sIgE concentrations ≥0.7kIU_A/l were pooled accordingly: pool 1-peanut and hazelnut, pool 2-egg white, cow's milk and cod fish, pool 3-soy, wheat and shrimp and pool 4-dust mite Dermatophagoides farinae, dog dander, cat dander, Timothy grass pollen, and silver birch pollen. Aliquots stored frozen, refrigerated and at room temperature were tested in duplicate (Phadia ImmunoCAP® 250) over two weeks. The relative difference was calculated for each sIgE as a percentage of the initial value and compared to the analytical reference change value.

Results: Minimal effects on specimen stability were noted for all sIgE analyzed under the three storage conditions tested in this study. All changes observed in sIgE concentrations were related to the assay variability and not to sample deterioration.

Conclusion: Serum allergen specific IgE concentrations are stable at all temperatures studied for up to 17days.

Keywords: Allergen specific IgE antibodies; Allergy testing; Specimen stability; sIgE.