NASAL PROVOCATION WITH ALLERGEN INDUCES A SECONDARY SERUM IGE ANTIBODY-RESPONSE

The study of the IgE response to seasonal antigen exposure is limited by its occurrence once a year and by the variability of patient exposu re to pollens. To overcome these problems, me investigated whether nas al challenge with antigen causes an increase in serum anti-ragweed IgE levels. We challenged individuals with ragweed allergy intranasally w ith nanogram quantities of ragweed antigen extract and measured their serum anti-ragweed IgE levels before and at weekly intervals after cha llenge. In a series of studies we found that there was a reproducible rise in antigen-specific serum IgE levels beginning the first week aft er challenge that plateaued at about 180% of baseline levels during th e fourth week and remained elevated for 8 weeks. Not all individuals s howed this response. The magnitude of the allergen-specific IgE respon se to nasal challenge appeared to be greater than the response to seas onal exposure. Treatment with intranasal beclomethasone before challen ge did not affect the response. The results demonstrate a human in viv o model for the study of the antigen-specific secondary IgE response t o allergen.