Clinical importance of non-specific lipid transfer proteins as food allergens.

Non-specific lipid transfer proteins (nsLTPs) have recently been identified as plant food allergens. They are good examples of true food allergens, in the sense that they are capable of sensitizing, i.e. inducing specific IgE, as well as of eliciting severe symptoms. This is in contrast with most plant food allergens, which are recognized because of primary sensitization to related inhalant allergens (cross-reactivity), i.e. pollen allergens. The basis of the difference between the latter category and strong food allergens such as nsLTPs appears to lie in the sensitivity of the allergens to proteolytic attack and food processing. Stability allows the allergen to reach the gastrointestinal immune system in an immunogenic and allergenic conformation, allowing sensitization and induction of systemic symptoms. Stability also explains the presence of such allergens in processed foods. Together, these characteristics make nsLTPs clinically highly relevant plant food allergens and ideal tools with which to study the mechanisms involved in food allergy.