In vivo and in vitro testing with rAni s 1 can facilitate diagnosis of anisakis simplex allergy

Background: Traditional diagnostic tests such as skin prick tests (SPT) and specific IgE (sIgE) against whole Anisakis simplex extract have low specificity. Consequently, allergy to A simplex is overdiagnosed. Objective: Our aim was to compare tests used in component-resolved diagnosis. Methods: We evaluated 34 patients with allergy to A simplex, 15 patients with acute urticaria who were sensitized to A simplex but had no clinical history of allergy to A simplex, and 10 patients allergic to seafood. SPT, sIgE (ELISA and ISAC-112), and the basophil activation test (BAT) were performed with A simplex whole extract and the molecular components rAni s 1, rAni s 3, and nPen m 1. Sensitivity and specificity were calculated and compared with different cutoffs. Results: With the A simplex whole extract, SPT, sIgE, and BAT yielded specificity values of 72%, 68%, and 70%, respectively, with a cutoff (wheal size) of 11.2 mm, an sIgE value of 7.9 kUA/L, and a stimulation index of 1.9. Specificity increased to 100% using the molecular component rAni s 1 with SPT, sIgE by ELISA, and ISAC-112. Neither rAni s 3 sensitization nor cross-reactivity with Pen m 1 was observed in patients sensitized to A simplex. Conclusion: rAni s 1 is recognized by 100% of our patients and is able to distinguish between patients allergic to A simplex and patients with acute urticaria who are sensitized to A simplex but have no clinical history of allergy to this parasite (AU)

Introducción: Las pruebas diagnósticas tradicionales como pruebas cutáneas (PC) e IgE específica (sIgE) con el extracto completo de Anisakis simplex tienen una baja especificidad. Esto conlleva a un sobrediagnóstico de alergia a A simplex. Objetivo: Nuestro objetivo fue comparar diferentes pruebas de diagnóstico basado en componentes moleculares. Métodos: Se estudiaron 34 pacientes con alergia a A simplex, 15 con urticaria aguda sensibilizados a A simplex pero sin historia clínica compatible con alergia a A simplex y 10 alérgicos a mariscos. A todos ellos se les realizaron PC, sIgE mediante ELISA e ISAC-112 y TAB con el extracto completo de A simplex y los componentes moleculares rAni s 1, rAni s 3 y nPen m 1. Se calculó y se comparó la sensibilidad y especificidad de cada prueba con diferentes puntos de corte. Resultados: Las PC, la sIgE y el TAB con el extracto completo de A simplex mostraron una especificidad del 72%, 68% y 70% con un punto de corte de 11,2 mm de tamaño de pápula, 7,9 kUA/L de sIgE y un índice de estimulación de 1,9, respectivamente. La especificidad incrementó al 100% utilizando el componente rAni s 1en PC e sIgE mediante ELISA e ISAC-112. No se observó sensibilización a rAni s 3 ni reactividad cruzada con nPen m 1 en los pacientes sensibilizados a A simplex. Conclusión: el alérgeno rAni s 1 es reconocido por el 100% de nuestros pacientes y nos permite distinguir entre pacientes alérgicos a A simplex y pacientes con urticaria aguda sensibilizados a A simplex sin historia clínica de alergia a éste parásito (AU)

In vivo and in vitro testing with rAni s 1 can facilitate diagnosis of Anisakis simplex allergy.

BACKGROUND: Traditional diagnostic tests such as skin prick tests (SPT) and specific IgE (slgE) against whole Anisakis simplex extract have low specificity. Consequently, allergy to A simplex is overdiagnosed. OBJECTIVE: Our aim was to compare tests used in component-resolved diagnosis. METHODS: We evaluated 34 patients with allergy to A simplex, 15 patients with acute urticaria who were sensitized to A simplex but had no clinical history of allergy to A simplex, and 10 patients allergic to seafood. SPT, slgE (ELISA and ISAC-I 12), and the basophil activation test (BAT) were performed with A simplex whole extract and the molecular components rAni s 1, rAni s 3, and nPen m 1. Sensitivity and specificity were calculated and compared with different cutoffs. RESULTS: With the A simplex whole extract, SPT, slgE, and BAT yielded specificity values of 72%, 68%, and 70%, respectively, with a cutoff (wheal size) of 11.2 mm, an slgE value of 7.9 kUAIL, and a stimulation index of 1.9. Specificity increased to 100% using the molecular component rAni s 1 with SPT, slgE by ELISA, and ISAC-112. Neither rAni s 3 sensitization nor cross-reactivity with Pen m 1 was observed in patients sensitized to A simplex. CONCLUSION: rAni s 1 is recognized by 100% of our patients and is able to distinguish between patients allergic to A simplex and patients with acute urticaria who are sensitized to A simplex but have no clinical history of allergy to this parasite.