Chinese Bellflower Root Anaphylaxis: IgE-Binding Components and Cross-Reactivity With Mugwort and Birch

A 56-year-old man who had suffered from seasonal rhinitis in spring and autumn experienced recurrent generalized urticaria and an oral burning sensation after eating several cooked herbs for 3 months. A skin-prick test showed positive responses to various pollens, celery, Chinese bellflower, and arrowroot. The Chinese bellflower-specific IgE ELISA OD value was 1.547. Oral challenge with unprocessed raw Chinese bellflower root provoked oral burning sensation, eyelid swelling, generalized urticaria, and hypotension. In an ELISA inhibition test, IgE binding to Chinese bellflower was significantly inhibited by Chinese bellflower, mugwort, and birch pollen extract. SDS-PAGE and immunoblot assay revealed nine IgE-binding components, and common protein bands were detected in the range of 40~55 kDa (Chinese bellflower-mugwort-birch) and 14 kDa (Chinese bellflower-birch). Chinese bellflower root can cause anaphylaxis and may have cross-reactivity with mugwort and birch.

Liposome entrapped allergen reduces plasma histamine in sensitized mice.

Immunotherapy of allergic diseases is associated with problems of adverse systemic reactions. We have shown earlier that liposome entrapped allergen (LEA) is effective in inducing IgG response and restricting IgE response in immunized mice. This mode of treatment may be more effective and safer if it can prevent anaphylaxis. To determine this feature, mice were administered allergen preparations repeatedly and later challenged with the same allergen. Mice given liposomal preparation showed lower specific IgE response as compared to the mice given free allergen or alum adsorbed allergen of Artemisia scoparia. Specific IgG response was higher in mice immunized with LEA. The mice immunized with liposomal preparation survived whereas others injected with free allergen or alum adsorbed allergen died probably due to anaphylaxis. High levels of histamine were observed in mice injected with free allergen as compared to the mice injected LEA. The increase in plasma histamine level may be the cause of anaphylaxis during allergen challenge. In conclusion, LEA could be used as a safe and effective mode of immunotherapy for allergy diseases, since it reduces plasma histamine levels considerably thereby reducing the chances of anaphylaxis.