Allergen-specific IgE detection
All patient serum sIgE samples were collected and tested by a certified third-party laboratory service provider, KingMed Diagnostics, with uniform and standardized procedures.
A full-automated in vitro allergen detector, the ImmunoCAP 1000 system (Thermo Fisher Scientific Inc., California, USA), was used to detect allergen-specific sIgE in the sera, as described elsewhere9, 11. The sIgE levels for nine categories of allergens (ImmunoCAP number, species source) were evaluated in this study, including those for the house dust mite (d1: house dust mite;Dermatophagoides pteronyssinus ), German cockroach (i6;Blatella germanica ), tree pollen mix (tx4: Quercus alba ,Ulmus americana , Platanus acerifolia , Salix caprea ,Populus deltoides ), mold mix (mx1: Penicillium chrysogenum , Cladosporium herbarum , Aspergillus fumigatus , Alternaria alternata ), dog dander (e5), egg whites (f1), cow’s milk (f2), crab (f23), and shrimp (f24). Positive reactivity was defined as an sIgE level ≥ 0.35 kUA/L (class 1 or above). According to the absolute sIgE levels, the reactivity was categorized quantitatively into six classes: class 1 (≥ 0.35 to < 0.70 kUA/L), class 2 (≥ 0.70 to <3.50 kUA/L), class 3 (≥ 3.50 to < 17.50 kUA/L), class 4 (≥ 17.50 to < 50.00 kUA/L), class 5 (≥ 50.00 to < 100.00 kUA/L), and class 6 (≥ 100.00 kUA/L) 9, 11.