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

Area of Science:

• Allergy diagnostics
• Immunology
• Food hypersensitivity

Background:

• Component-based diagnosis using multiplex platforms is common for food allergies.
• Clinical performance of these platforms in nut allergy remains unevaluated.

Purpose of the Study:

• To evaluate the diagnostic performance of a commercial protein microarray (ISAC 112) for specific IgE (sIgE) detection in peanut, hazelnut, and walnut allergies.
• To compare ISAC results with ImmunoCAP for key nut allergens, including lipid transfer proteins (LTPs).

Main Methods:

• Measured sIgE in 36 peanut-, 36 hazelnut-, and 44 walnut-allergic patients using ISAC 112.
• Utilized ImmunoCAP for sIgE determination in patients with negative ISAC results and for specific LTPs (Ara h 9, Cor a 8, Jug r 3).
• Compared sIgE levels between ISAC and ImmunoCAP.

Main Results:

• High sensitization rates to nut LTPs were observed (Ara h 9: 66.7%, Cor a 8: 80.5%, Jug r 3: 84%).
• ISAC failed to detect sIgE in a significant proportion of patients (peanut: 33.3%, hazelnut: 13.9%, walnut: 13.6%).
• ImmunoCAP identified additional sensitizations, particularly for Ara h 9 (61.5% of ISAC-negative peanut-allergic patients), and showed higher detection rates for Ara h 9 in LTP-sensitized individuals compared to ISAC (94.4% vs 72.2%, P < .05).

Conclusions:

• The ISAC microarray demonstrates adequate diagnostic performance for hazelnut and walnut allergies.
• The diagnostic performance of ISAC is insufficient for peanut allergy, particularly concerning Ara h 9 sensitization.
• Improvements in sIgE sensitivity for Ara h 9 on the ISAC platform are necessary for accurate peanut allergy diagnosis.