Is microarray analysis really useful and sufficient to diagnose nut allergy in the mediterranean area?

ABSTRACT

Background: Component-based diagnosis on multiplex platforms is widely used in food allergy but its clinical performance has not been evaluated in nut allergy. Objective: To assess the diagnostic performance of a commercial protein microarray in the determination of specific IgE (sIgE) in peanut, hazelnut, and walnut allergy. Methods: sIgE was measured in 36 peanut-allergic, 36 hazelnut-allergic, and 44 walnut-allergic patients by ISAC 112, and subsequently, sIgE against available components was determined by ImmunoCAP in patients with negative ISAC results. ImmunoCAP was also used to measure sIgE to Ara h 9, Cor a 8, and Jug r 3 in a subgroup of lipid transfer protein (LTP)-sensitized nut-allergic patients (positive skin prick test to LTP-enriched extract). sIgE levels by ImmunoCAP were compared with ISAC ranges. Results: Most peanut-, hazelnut-, and walnut-allergic patients were sensitized to the corresponding nut LTP (Ara h 9, 66.7%; Cor a 8, 80.5%; Jug r 3, 84% respectively). However, ISAC did not detect sIgE in 33.3% of peanut-allergic patients, 13.9% of hazelnut-allergic patients, or 13.6% of walnut-allergic patients. sIgE determination by ImmunoCAP detected sensitization to Ara h 9, Cor a 8, and Jug r 3 in, respectively, 61.5% of peanut-allergic patients, 60% of hazelnut-allergic patients, and 88.3% of walnut-allergic patients with negative ISAC results. In the subgroup of peach LTP-sensitized patients, Ara h 9 sIgE was detected in more cases by ImmunoCAP than by ISAC (94.4% vs 72.2%, P<.05). Similar rates of Cor a 8 and Jug r 3 sensitization were detected by both techniques. Conclusions: The diagnostic performance of ISAC was adequate for hazelnut and walnut allergy but not for peanut allergy. sIgE sensitivity against Ara h 9 in ISAC needs to be improved (AU)

RESUMEN

Introducción: La utilidad clínica del diagnóstico por componentes no ha sido evaluada en el estudio de la alergia a frutos secos (FS). Objetivo: Evaluar la capacidad diagnóstica de una micromatriz comercial de proteínas alergénicas en la alergia a cacahuete, avellana y nuez. Métodos: Se determinó la sIgE en pacientes alérgicos a FS mediante la micromatriz ISAC 112, e ImmunoCAP en los pacientes con sIgE negativa frente a los componentes de ISAC. Además, se realizó ImmunoCAP frente a Ara h 9, Cor a 8 y Jug r 3 en un subgrupo de pacientes sensibilizados a LTP. La sIgE detectada por ImmunoCAP fue comparada con los rangos de ISAC. Resultados: La mayoría de los alérgicos a cacahuete (66,7%), avellana (80,5%) y nuez (84%) estaba sensibilizados a su LTP. Sin embargo, no se detectó sIgE frente a los componentes de ISAC en el 33,3% de alérgicos a cacahuete, 13,9% de alérgicos a avellana y 13,6% de los alérgicos a nuez. El ImmunoCAP permitió detectar sIgE a Ara h 9 en 61,5%, Cor a 8 en 60% y Jug r 3 en 83,3% de los ISAC negativo. En el subgrupo LTP, ImmunoCAP (94,4%) fue superior a ISAC (72,2%) en la detección de sIgE a Ara h 9 (p<0,05). La sIgE frente a Cor a 8 y Jug r 3 fue detectada de forma similar por ambas técnicas. Conclusiones: La micromatriz ISAC es adecuada para el diagnóstico de alergia a avellana y nuez. La sensibilidad del componente Ara h 9 de ISAC debe ser mejorada (AU)