Kidney-bean (Phaseolus Vulgaris) Dependent, Exercise-induced Anaphylaxis in Patients Comorbid with Mugwort (Artemisia Vulgaris) Pollinosis.

BACKGROUND The cross-reactive allergen between mugwort (Artemisia vulgaris) and kidney bean (Phaseolus vulgaris) has not yet been identified. METHODS A total of 24 patients were included in this study. The sera of patients were analyzed for the concentrations of specific IgE antibodies. The allergenicity and cross-reactivity were investigated by Western blotting and immunoblot inhibitory experiments. RESULTS The immunoblotting indicated the binding of patients' IgE to crude mugwort extract at ~26 kDa protein (15 cases), ~60 kDa (15 cases), and 10-15 kDa proteins (12 cases). The results of the immunoblot-inhibition assay showed that kidney bean seed extract inhibited specific IgE binding to mugwort at 10-15 kDa, ~26 kDa, and ~60 kDa in 4 (16.7%), 1 (4.2%) and 2 (8.3%) cases, respectively. On the other hand, mugwort extract was demonstrated to inhibit specific IgE binding to kidney bean seed at 10-15 kDa, 15-20 kDa, ~30 kDa, and 60 kDa in 1 (4.2%), 3 (12.5%), 4 (16.7%), and 3 (12.5%) cases, respectively. CONCLUSION The 26-30 kDa, 10-15 kDa, and 60 kDa proteins are potential causative agents of the cross-reactivity between mugwort and kidney beans. The findings of this study improved the current understanding on the allergenicity of kidney beans and would provide insights into the refinement of treatment strategy for anaphylaxis.