D1.33 - Oat Allergy in a Young Adult: Allergenic Protein Profiling and Clinical Implications

Oat (Avena sativa) is a cereal from the Poaceae family that has become very popular in our setting due to its high nutritional value. Oat allergy is a rare but clinically significant condition. We report the case of a 19-year-old male, with medical history of rhinoconjunctivitis and asthma with exercise, who presented a systemic reaction to oats with the aim of identifying the allergenic proteins responsible and their possible clinical implications.

The patient presents oropharyngeal pruritus and shortness of breath within minutes of consuming homemade cookies containing oats. Skin tests (SC) with cereals, prick-prick tests with oat grain and oat bran, specific IgE determination against allergens (ImmunoCAP) and protein extracts from oat flour, flakes, and bran were analyzed using SDS-PAGE and Western blot to determine protein profiles and IgE reactivity.

Skin prick tests were positive for oat grains and oat bran and negative for other cereals. The IgE value for oats was 0.84 kUA/L. Western blot analysis identified significant IgE reactivity to proteins in all oat extracts. Key findings included a 50 kDa protein (serpin), a 37 kDa protein, and a 22.5 kDa band in oat bran corresponding to the 12S seed globulin protein.

We present a case of IgE-mediated anaphylaxis to oat with identification of specific serpin-like proteins and 12S globulin.  Further studies on cross-reactivity between cereals and seeds are important to develop effective strategies to reduce allergenic risks in affected patients.