Introduction:

Food allergy affects millions of people globally. Lipid transfer proteins (LTP) are panallergens presente in plant foods and sensitization symptoms vary from oral allergy syndrome (OAS) to anaphylaxis.

Objective: Characterization of clinical and molecular sensitization profile of patients with history of previous reaction to foods containing LTP.

Material and methods:

Retrospective study including 15 patients with history of systemic reaction to foods containing LTP. Patients were characterized for symptoms and sensitization in skin prick tests (SPT) with commercial extract and food in nature (SPT prick-prick). MacroArray Allergy Explorer-ALEX® was performed to evaluate total IgE, specific IgE for molecular components (IgEmc) and total extracts (IgEte) values.

Results:

Fifteen patients, 73% women, mean age 30.7±13.7 years old. Mean age in first episode was 21.8±10.5 years old, manifesting as: anaphylaxis n=8 (apple, peach, nuts), urticaria/angioedema n=4 (apple, peach, peanut) and OAS n=3 (apple, peach, peanut). Mean total IgE: 430.5kU/L. The following LTP (N;IgE mean±standard deviation-kU/L) were identified: Pru p 3 (15;15.7±21.5), Ara h 9 (10;2.9±4), Mal d 3 (9;1.5±1.7), Act d 10 (6;0.6±1), Vit v 1 (6;1.8±2.5), Cor a 8 (4;0.1±0.2), Sola l 6 (1;0.88). For peach, all associations between symptoms, cutaneous tests and IgE values obtained a correlation of k=1; furthermore, symptoms agreement with SPT+SPT prick-prick was higher for apple (k=0.44, p=0.03); symptoms agreement with IgEte was higher for peanut (k=0.87, p<0.01); symptoms agreement with IgEmc was higher for hazelnut (k=0.70, p<0.01) and grape (k=0.55, p=0.02).

Conclusions:

ALEX® method allows simultaneous identification of total IgE, IgEte and IgEmc, simplifying the interpretation and clinical correlation of the results. In this study we demonstrate for different foods that the diagnostic method with greater correlation with clinic is variable and dependent on the food. A broader prospective study is needed to assess the sensitivity and specificity of this test.

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