Serological characteristics of peanut allergy

Background Peanut is the most common cause of severe or fatal food-associat ed anaphylaxis. Studies indicate that peanut extracts contain many allergen ic proteins. The identification of major and minor allergenic components is necessary for standardization of experimental and diagnostic extracts. Objective To identify further major and minor allergenic components of pean ut extract using a large population of peanut allergies, and to relate sero logical findings to clinical parameters. Methods The crude peanut extract was fractionated by fast protein liquid ch romatography and the IgE binding proteins identified by sodium dodecyl sulp hate polyacrylamide gel electrophoresis followed by western blotting. Serum from 89 peanut allergies with a positive history of peanut allergy and ele vated specific IgE and control serum from four atopic and four non-atopic, non-peanut allergies were used. Results Nineteen peanut proteins were found to bind IgE from peanut allergi c sera. Over 70% of subjects reacted to protein bands of 63 and 17 kDa (con sistent with Ara h 1 and Ara h 2, respectively), confirming the importance of these two proteins as major allergens, A high proportion of patient sera also bound proteins at 15, 10, 30. 18 and 51 kDa in decreasing order. The percentage of cases with sensitivity to a 15 kDa protein was found to be hi gher in patient groups with severe reactions to peanut. Conclusion This study highlights the diversity of peanut allergens. Diagnos tic extracts containing a high proportion of the 15 kDa component may aid i n diagnosis.