[Positive ratio of allergen specific IgE antibodies in serum, from a large scale study]

Incidences of allergen specific IgE antibodies in a large Japanese population(n = 4,797,158) were studied. Sera from patients were collected in our laboratories during 1994-1998, and assayed with Pharmacias CAP system FEIA. Values greater than 0.70 UA/ml(Score 2) were considered positive. Japanese cedar pollen showed the highest IgE response(positive ratio), followed by house dust, and dust mite. Among food allergens, apple had the highest response, followed by sesame seed, egg white, potato, and tomato. IgE response against Anisakis was significantly higher than that against seafood. Positive ratio varied significantly among regions and among seasons. For example, Hokkaido, compared to other regions, showed lower values for cedar and cypress, but higher for silver birch. Values used in this study were from patients who chose IgE testing, and thus do not represent the general population. However, our findings include positive ratios of rare allergens, and are useful for clinicians who do allergen testing.