Diagnostic capacity of commercial extracts vs prick-by-prick in the study of sensitization to peanut: which technique should we use?

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Is the ISAC 112 Microarray Useful in the Diagnosis of Pollinosis in Spain?

BACKGROUND: Multiple sensitization is frequent among pollen-allergic patients. The goal of this study was to determine the diagnostic accuracy of the ImmunoCAP ISAC 112 (ISAC112) microarray in allergy to pollen from several taxa and its clinical utility in a Spanish population. METHODS: Specific IgE was determined in 390 pollen-allergic patients using the ISAC112 microarray. Diagnostic accuracy (sensitivity, specificity, predictive values, and area under the ROC curve) was calculated for the diagnosis of allergy to pollen from grass (n=49), cypress (n=75), olive tree (n=33), plane tree (n=63), and pellitory of the wall (n=17) and compared with that of the singleplex ImmunoCAP immunoassay. RESULTS: The sensitivity of the ISAC112 microarray ranged from 68.2% for allergy to plane tree pollen to 93.9% for allergy to grass pollen. The specificity was >90%. The AUC for the diagnosis of allergy to plane tree pollen was 0.798, whereas the AUC for the remaining cases was ≥0.876. The accuracy of ISAC112 was higher than that of ImmunoCAP for plane tree pollen and similar for the remaining pollens. The frequency of sensitization to most species-specific allergenic components and profilins varied between the different geographical regions studied. A total of 73% of pollen-allergic patients were sensitized to species-specific components of more than 1 pollen type. CONCLUSIONS: The ISAC112 microarray is an accurate tool for the diagnosis of allergy to pollen from grass, cypress, olive tree, plane tree, and pellitory of the wall. The features of the ISAC112 microarray are similar or superior (in the case of plane tree pollen) to those of ImmunoCAP. This microarray is particularly useful for the etiologic diagnosis of pollinosis in patients sensitized to multiple pollen species whose pollination periods overlap.

Is Microarray Analysis Really Useful and Sufficient to Diagnose Nut Allergy in the Mediterranean Area?

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, Cora 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 Cora 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.

Comparable actions of omalizumab on mast cells and basophils.

BACKGROUND: Omalizumab (OmAb) has recently been approved for the treatment of diseases other than allergic asthma, including chronic urticaria. The exploration of the use of OmAb in chronic urticaria was based on the presence of IgE autoantibodies against autoantigens such as anti-IgE, anti-FcεRI, and IgE antibodies against thyroid peroxidase in certain patients with chronic urticaria. OmAb recognizes and sequesters free IgE to prevent its interaction with FcεRI. However, OmAb is equally and rapidly effective against autoimmune and non-autoimmune urticaria, suggesting the possible involvement of additional mechanisms of IgE. OBJECTIVES: We sought to investigate the in vitro mechanism of action of OmAb in mast cells and basophils. METHODS: Both LAD2 human mast cell line, previously sensitized with IgE, and ex vivo basophils were incubated with OmAb at different doses, analysing its effect on IgE-dependent events (e.g., degranulation, phosphorylation-mediated signalling, and eicosanoid release). RESULTS: We found that OmAb dissociates pre-bound IgE from mast cells and basophils, resulting in a reduction of proximal phosphorylation-mediated signalling events (Syk, PLCγ, and LAT) and in a decrease in degranulation and leukotriene synthesis. CONCLUSION: Our data prove the existence of common mechanisms of action of OmAb in mast cells and basophils that would explain its effectiveness and rapid effect in chronic urticaria and provide a basis for its use in other diseases mediated by these cells.

Is the ISAC 112 microarray useful in the diagnosis of pollinosis in Spain?

Background: Multiple sensitization is frequent among pollen-allergic patients. The goal of this study was to determine the diagnostic accuracy of the ImmunoCAP ISAC 112 (ISAC112) microarray in allergy to pollen from several taxa and its clinical utility in a Spanish population. Methods: Specific IgE was determined in 390 pollen-allergic patients using the ISAC112 microarray. Diagnostic accuracy (sensitivity, specificity, predictive values, and area under the ROC curve) was calculated for the diagnosis of allergy to pollen from grass (n=49), cypress (n=75), olive tree (n=33), plane tree (n=63), and pellitory of the wall (n=17) and compared with that of the singleplex ImmunoCAP immunoassay. Results: The sensitivity of the ISAC112 microarray ranged from 68.2% for allergy to plane tree pollen to 93.9% for allergy to grass pollen. The specificity was >90%. The AUC for the diagnosis of allergy to plane tree pollen was 0.798, whereas the AUC for the remaining cases was ≥0.876. The accuracy of ISAC112 was higher than that of ImmunoCAP for plane tree pollen and similar for the remaining pollens. The frequency of sensitization to most species-specific allergenic components and profilins varied between the different geographical regions studied. A total of 73% of pollen-allergic patients were sensitized to species-specific components of more than 1 pollen type. Conclusions: The ISAC112 microarray is an accurate tool for the diagnosis of allergy to pollen from grass, cypress, olive tree, plane tree, and pellitory of the wall. The features of the ISAC112 microarray are similar or superior (in the case of plane tree pollen) to those of ImmunoCAP. This microarray is particularly useful for the etiologic diagnosis of pollinosis in patients sensitized to multiple pollen species whose pollination periods overlap (AU)

Introducción: La sensibilización a múltiples pólenes es frecuente entre los pacientes alérgicos a polen. El objetivo de este estudio fue determinar la exactitud diagnóstica de la micromatriz ImmunoCAP ISAC 112 (ISAC112) en alergia a polen de diversos taxones y su utilidad clínica en una población española. Métodos: Se determinó IgE específica mediante ISAC112 en 390 pacientes polínicos. Se calculó su exactitud diagnóstica (sensibilidad, especificidad, valores predictivos y área bajo la curva ROC) para el diagnóstico de alergia a polen de gramíneas (n=49), ciprés (n=75), olivo (n=33), plátano de sombra (n=63) y parietaria (n=17) y se comparó con la de ImmunoCAP monocomponente (CAP). Resultados: La sensibilidad de ISAC112 osciló entre 68,2% para alergia a polen de plátano de sombra y 93,9% a polen de gramíneas. La especificidad se situó por encima del 90% en todos los casos. El área bajo la curva (AUC) de la curva ROC para diagnóstico de alergia a polen de plátano fue de 0,798. El resto de AUC fueron ≥ 0,876. La exactitud diagnóstica de ISAC112 fue superior a la de CAP para la alergia a polen de plátano de sombra y similar para el resto de pólenes estudiados. La frecuencia de sensibilización a la mayoría de componentes alergénicos genuinos y a profilinas varió entre las diferentes zonas. El 73 % de los pacientes polínicos estaban sensibilizados a componentes genuinos de más de un tipo polínico. Conclusiones: ISAC112 es una herramienta exacta para el diagnóstico de alergia al polen de gramíneas, ciprés, olivo, plátano de sombra y parietaria, con prestaciones similares o superiores, en el caso de alergia a polen de plátano de sombra, a las de CAP. Es especialmente útil para el diagnóstico etiológico de la polinosis en pacientes con sensibilizaciones a múltiples pólenes con periodos de polinización solapados (AU)

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

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)

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)

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.

In Vitro Production of Ag-Specific IFN-?? in Patients With Delayed Hypersensitivity to Amoxicillin

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