Analysis of Soy Allergy Using Molecular Component Testing

RATIONALE: Soy allergy is one of the most common food allergies. The presence of IgE specific to soy component storage proteins Gly m4, m5, and m6 has been indicated as a means to improve the specific identification of systemic and local soy allergic reactions.

METHODS: A retrospective review of national laboratory data was performed over samples testing for IgE to Gly m4, 5, and 6 (Phadia ImmunoCAP). Data from de-identified patient samples were compiled into risk groups based on current research utilizing the international standard cutoff of 0.35kU/L as a positive test for IgE.

RESULTS: Of the sample set, 46% of patients were responsive to at least one soy component. Of these, 39% of patients display response to only Gly m5 and 6, the components most indicative of a severe and systemic response to soy. Patients responsive to Gly m4 only represented 37%, and 15% were responsive to all components. Few patients were responsive to Gly m5 or 6 separately or associated with Gly m4. Nearly 60% of positive pediatric (<10Y) patients were responsive to both Gly m5 and 6 and only 14% to Gly m4 alone. Patients older than 10 years predominantly respond to Gly m4 alone over m5 and m6 only (54% to 24%).

CONCLUSIONS: Molecular component allergy testing represents a major step forward in assessing risk of soy allergies and constructing an appropriate medical response. A significant rate of specificity between the identification of markers for systemic and local/non-specific reactions indicates the importance of this information for patients and their families.