Maximal rise in IgE antibody following ragweed pollination season.

Patients allergic to ragweed pollen who did not receive immunotherapy had an increase in ragweed-specific IgE antibodies associated with seasonal exposure. Of 17 such patients, 15 reached peak levels between mid-September and mid-October. Two had peak values after mid-October; the levels were only slightly higher than earlier values. Our study shows that serum obtained in mid-October reflects approximately the maximal IgE antibody level attained 0y ragweed-sensitive patients in our area and that this value can be used as a baseline in monitoring the subsequent decline in antibodies. In addition, our data support an earlier observation that the magnitude of seasonal rise in IgE antibody is related to the preseasonal value. The significantly positive correlation of the results of carefully performed skin tests (end point titration) with radioallergosorbent test (RAST) values suggests the possibility that the RAST can be employed as a reliable diagnostic aid, perhaps even replacing the skin test.