The ImmunoCAP ISAC molecular allergology approach in adult multi-sensitized Italian patients with respiratory symptoms.

Objective: To evaluate the performances of an allergen microarray in multi-sensitized allergic patients with respiratory symptoms.

Methods: 321 patients and 92 controls were included in this study. Specific serum IgE were assayed using ImmunoCAP ISAC, a microarray containing 103 components derived from 47 allergens and results were compared with extract-based ImmunoCAP Allergens sIgE to 15 common airborne allergens.

Results: The reproducibility of ISAC was good. The Positive Percent Agreement (PPA) varied between 75% and 100% for sIgE levels above 1 kUA/l. For samples with sIgE levels below 0.1 kUA/l, the Negative Percent Agreement (NPA) ranged between 90% and 100%. Notably, 58% of respiratory allergy patients had IgE to food-specific proteins and 52% resulted sensitized to cross-reactive pan-allergens.

Conclusions: ImmunoCAP ISAC detects allergen sensitization at component level and adds important information by defining both cross and co-sensitization to a large variety of allergen molecules.