IGHE and Allergy: To insure we only evaluated atopic patients who had documented allergies to the circulating aeroallergen, we selected a group of atopic subjects with positive skin prick or IgE blood tests specific for grasses, trees, and/or ragweed and collected the blood during the non-allergen season, and during pollen season (spring when the grasses and tree pollens were high and the fall when the ragweed counts were elevated in Atlanta (Fig. 1c).