The Biochemical Basis and Clinical Evidence of Food Allergy Due to Lipid Transfer Proteins: A Comprehensive Review

Abstract

Plant lipid transfer proteins (LTPs) are ubiquitous proteins that are found in divergent plant species. Although the exact function of LTPs is not fully understood, LTPs are conserved across a broad range of plant species. Because LTPs share structural features, there is an increased probability for significant allergic cross-reactivity. The molecular features of LTPs also decrease the probability of degradation due to cooking or digestion, thereby increasing the probability of systemic absorption and severe allergic reactions. LTP allergy, unlike other forms of anaphylaxis, tends to occur more frequently in areas of lower latitude. The geographic distribution of LTP allergy, along with evidence of increased sensitization after respiratory exposure, has led to the hypothesis that LTP-related food allergy may be secondary to sensitization via the respiratory route. Clinical reactions associated with LTPs have broad clinical phenotypes and can be severe in nature. Life-threatening clinical reactions have been associated with ingestion of a multitude of plant products. Component-resolved diagnosis has played a significant role in research applications for LTP allergy. In the future, component-resolved diagnosis may play a significant role in day-to-day clinical care. Also, quantitative analysis of LTPs in foodstuffs may allow for the identification and/or production of low-LTP foods, thereby decreasing the risk to patients with LTP allergy. Furthermore, sublingual immunotherapy may provide a therapeutic option for patients with LTP allergy.