Food challenge with increased total IgE

There are no specific recommendations to my knowledge. Some clinicians “factor in” high total IgE in their interpretation of specific-IgE with the argument that a give specific-IgE is more important with lower total IgE. This makes sense if mast cells and basophils have IgE with multiple specificities on their surface, then a given concentration of specific-IgE would have less opportunity to cross-link in the “sea of IgE”. However, I am not aware of any specific correction factors for interpretation of specific-IgE in light of total IgE.

I will share you question with Dr. Scott Sicherer, a deputy editor of the Journal of Allergy and Clinical Immunology: In Practice and internationally recognized expert in food allergy, for his comments.

Sicherer Reply:
I agree with Dr. Ledford’s reply. I will clarify that think the question regards food-specific IgE “cut-offs” rather than a “guideline” per se. So the question would for example be “Should we interpret an egg white IgE level of 2 kU/L differently if the total IgE were 10 versus 3,000”. The relatively few studies correlating food-specific IgE to food challenge outcomes derived the various “cut-offs” on atopic participants, often with atopic dermatitis, who generally run higher IgE. In that sense a “fudge factor” may have played a part in these determinations. A number of studies have addressed taking into consideration the total IgE with mixed conclusions.1-3 My clinical approach mirrors Dr. Ledford’s comments--I consider very high total IgE at the extreme values to consider food challenges more liberally, but base this more on the individual patient’s tests and experiences with food allergic reactions rather than any specific adjustment.

1. Gupta RS, Lau CH, Hamilton RG, Donnell A, Newhall KK. Predicting outcomes of oral food challenges by using the allergen-specific IgE-total IgE ratio. J Allergy Clin Immunol Pract 2014; 2:300-5.
2. Mehl A, Verstege A, Staden U, Kulig M, Nocon M, Beyer K, et al. Utility of the ratio of foodspecific IgE/total IgE in predicting symptomatic food allergy in children. Allergy 2005; 60:1034-9. 3. Grabenhenrich L, Lange L, Hartl M, Kalb B, Ziegert M, Finger A, et al. The component-specific to total IgE ratios do not improve peanut and hazelnut allergy diagnoses. J Allergy Clin Immunol 2016; 137:1751-60 e8.