Background: Plants of the genus Artemisia are a source of fall allergi
c symptoms, particularly in the western United States. Studies have ch
aracterized the allergens in one of the major species (A. vulgaris) bu
t currently there are no cross-reactivity data on the major United Sta
tes species. Objective: The purpose of this study was to investigate t
he in vitro cross-reactivity among nine Artemisia species: A, frigida,
A. annua, A. biennis, A. filifolia, A. tridentata, A. californica, A,
gnaphalodes, A. ludoviciana, and A. vulgaris. Methods: The cross-reac
tivity was demonstrated with the use of enzyme-linked immunosorbent as
say (ELISA) inhibitions and immunoblotting techniques utilizing a seru
m pool from patients allergic Co Artemisia species. Results: The enzym
e-linked immunosorbent assay inhibitions revealed strong cross-reactiv
ity among all nine species with A. biennis and A. tridentata being two
of the strongest inhibitors. The polyacrylamide gel electrophoresis s
howed a great deal of similarity in the bands among the nine species.
The nitrocellulose blots showed similar IgE binding patterns among the
Artemisia species with strong inhibition among all nine extracts. Con
clusions: These data all demonstrate very strong in vitro cross-reacti
vity among the nine Artemisia species studied. Such data have signific
ant clinical relevance, suggesting that a single Artemisia species may
be sufficient for allergy skin testing and formulation of immunothera
py extracts.