Yearly and seasonal changes of specific IgE to Japanese cedar pollen in a young population

Background: There have been no detailed long-term observations of the relationship between specific IgE production and stimulation by various naturally occurring allergens. Objective: This study was conducted to elucidate the yearly and seasonal changes of specific IgE antibody production to Japanese cedar pollen, an allergen of Japanese cedar pollinosis, in young adults. Methods: The numbers of Japanese cedar pollen were counted over a period of 9 years. Changes in the percentages of antibody carriers to Japanese cedar pollen and mite were examined during these years, Changes in Japanese cedar pollen-specific IgE levels between a low exposure year and a high exposure year in individual subjects were also investigated. Results: From 1987 to 1995, the percentages of Japanese cedar pollen-IgE carriers varied from about 30% to 50% with the intensity of pollen stimulation, and carriers tended to increase yearly, The rates of anti-mite IgE carriers changed little. In the spring which is the pollen season, Japanese cedar pollen-IgE levels in low exposure years were weaker than those in high exposure years in individual subjects, Levels in autumn, which is not the pollen season, showed equivalent levels in both high and low exposure years. Anti-mite IgE levels in individual subjects varied little during these years. Conclusions: A long-term follow-up study supported that Japanese cedar pollen-IgE production is mainly associated with the degree of allergen exposure.