459 Sunflower Seed Food Allergy as a Co-allergy With Peanut S. S. Comstock, C. Kath, S. S. Teuber; Univ CA-Davis School Medicine, Davis, CA. RATIONALE: Sunflower seed allergens are not well-described. Because sunflower seed butter may be consumed as an alternative to peanut butter by peanut-allergic individuals or those trying to avoid sensitization to peanut, issues of co-allergy are important. METHOD: Volunteers with self-reported severe nut and/or seed allergies were recruited. Subjects were interviewed and asked if they had ever eaten the following foods and if they had any symptoms upon ingestion: different tree nuts, peanut, sunflower seeds, pumpkin, or sesame seeds. Sera donated by some subjects were used in IgE immunoblots against raw sunflower seed extract and sunflower butter extract. RESULTS: In our population of seed or nut-allergic individuals, coallergy to peanut and sunflower seed was reported by 20 of 210 patients with peanut allergy (9.5%). Sera from patients with sunflower and peanut allergy showed IgE binding to multiple sunflower polypeptide bands in both the seed and butter extracts. The roasted sunflower butter extract contained more high molecular weight polypeptides in a Coomassie-stained gel. Much, but not all, of the IgE reactivity was absorbed out by preincubation of sera with perennial ryegrass pollen extract. 31 patients with peanut allergy, but no known sunflower seed allergy were also screened (some of whom had never eaten sunflower seeds), and 9 showed IgE binding to sunflower proteins. CONCLUSIONS: Some patients with peanut allergy are clinically allergic to both peanut and sunflower by self-report. Also, a percentage of patients with peanut allergy have sunflower seed-reactive IgE that may not be clinically relevant. Funding: University of California, Davis.