Clinical Implications

Profilins: Small proteins with great homology even in distantly related species. Sensitive to heat and enzymes. Mainly local reactions. Minor allergen components, may have extensive cross-reactivity to both foods and pollens.
PR-10 proteins: Widely distributed and cross-reactive panallergens. Heat-labile proteins primarily localized to the pulp of fruit. Mainly local reactions. Sensitized patients may exhibit oral allergy syndrome to fresh fruits or be cross-reactive to a peanut component.
Lipid transfer proteins (LTPs): Small, stable proteins that exist primarily in the peels of fruits and vegetables. High resistance to heat and enzymes, not destroyed by gastric acid. Systemic reactions common. Sensitized patients may be at risk for anaphylaxis, despite food processing or cooking.
Storage proteins: More heat- and enzyme-stable than PR-10 or profilins. Systemic reactions common. Sensitization constitutes an important risk marker for severe systemic reactions. Reactions to cooked and processed foods are possible.
Cross-reactive carbohydrate determinants (CCDs): Linked to proteins; include glycans present in plants but not mammals. Sensitized patients likely to have cross-reactivity, which may induce clinical symptoms.

Table 1. Plant food protein families.