Assessment of allergen sensitization in a general population-based survey (European Community Respiratory Health Survey I).

PURPOSE: Exposed to a common environment, the IgE-mediated immune response differs, for instance, among sensitized subjects, some of them reacting toward one allergen (monosensitized) whereas others are sensitized to a wide array of allergens (polysensitized). However, a better phenotypic characterization is needed for epidemiologic studies. Using the data collected during the ECRHS I (European Community Respiratory Health Survey), several assessments of skin prick tests and serum-specific IgE to identify mono- and polysensitized patients were compared.

METHODS

Subjects took part in the ECRHS-I. The CAP-System was used for serum allergen-specific IgE, and allergen-coated Phazet was used for prick tests. Four allergens (Dermatophagoides pteronyssinus, cat, timothy grass, and Cladosporium) were measured using IgE and nine (the same ones plus olive pollen, birch, Alternaria, Parietaria, and ragweed) were skin tested. One to two local allergens were also tested, depending on countries.

RESULTS

Prevalence of sensitization in 11,355 subjects (34.0 [27.9-40.1] years, 49.9% men) ranged from 32.3% (four specific IgE, 19.3% mono- and 13.0% polysensitized) to 41.8% (four specific IgE combined to nine prick tests, 19.6% mono- and 22.2% polysensitized). Concordance between four specific IgE and four prick tests was weak (weighted κ 0.65 [0.64-0.66]). Concordance between seven and nine prick tests was high (weighted κ 0.99 [0.98-1.00]). Local allergens induced small changes in the prevalence of sensitization, and reclassified some subjects from mono- to polysensitized.

CONCLUSIONS

Skin tests or serum-specific IgE may be chosen to identify allergenic sensitivity, mono- and polysensitized subjects without being strictly interchangeable.