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.