IgE-mediated reactivity to non-specific lipid transfer protein (nsLTP): clinical implications and management ‒ a consensus document of the Association of Italian Territorial and Hospital Allergists and Immunologists (AAIITO)
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Authors Information
1Allergology Clinic, Clinica San Carlo, Paderno Dugnano, Milan, Italy
2Department of Internal Medicine, IRCCS Foudation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
3Immunology and Allergology Unit, S. Maria degli Angeli Hospital, Pordenone, Italy
4SOS Allergology and Clinical Immunology, USL Toscana Centro, Prato, Italy
5Clinical and Laboratory Molecular Allergy Unit, IDI-IRCCS, Rome, Italy
History
Published: 20 October 2023
Accepted: 12 October 2023
Received: 04 September 2023
SUMMARY
The primary cause of adult-onset food allergy in Mediterranean countries is IgE-mediated reactivity to non-specific Lipid Transfer Protein (nsLTP), with a prevalence of 9.5% in Italy. nsLTP is heat- and pepsin-stable due to its 3D structure, causing severe allergic reactions, even anaphylaxis. It’s conserved across plants and a “panallergen” due to homologous forms in various vegetable foods. Found in Rosaceae fruits’ skin, it’s categorized into nsLTP1 (9 kDa) and nsLTP2 (7 kDa), representing 93% and 7% of the molecules described to date, respectively. Pru p 3 (nsLTP1) from peach is a primary sensitizer, binding more epitopes than other homologs. Cross-reactivity varies in sensitized patients, influenced by IgE levels. Clinical manifestations range from none to various symptoms. Managing patients sensitized to nsLTP without clinical allergy is a challenge. Sensitization hierarchy usually starts with peach, then expands through Prunoideae, Rosaceae, and other foods. Clinical symptoms don’t always expand across LTPs. Patients can tolerate some nsLTP-containing foods and consuming them may maintain tolerance. The absence of guidelines led to the Associazione Allergologi Immunologi Italiani Territoriali e Ospedalieri (AAIITO) creating a consensus-based document. Strategies involve avoidance, self-injectable adrenaline, verification through in vivo and in vitro testing, considering cofactors, and peeling fruits. In localized reactions, abstinence is recommended if specific IgE is high. Concurrent pollinosis may complicates diagnosis, but may help management since symptoms are often less severe. Asymptomatic patients are advised to continue normal diets while considering cofactors and total IgE levels. Management strategies should be case-specific, based on expert Consensus Document.
