Background: There is few data to prove the safety of egg shell calcium as allergen. Especially, non-calcinated egg shell calcium is not allowed to use without the description of origin of egg on food labels in Japan.
Method: We evaluated the possibly contaminated egg allergens in commercial non-calcinated egg shell calcium made from egg by in vitro methodologies (SDS-PAGE, western blotting, inhibition ELISA and sandwich ELISA) and by single-blind oral non-calcinated egg shell calcium challenge on 6 egg hypersensitivity patients.
Results: The allergenic activity of non-calcinated egg shell calcium was almost negligible compared to egg white by all in vitro methods. Furthermore, six patients with egg hypersensitivity were unresponsive to oral non-calcinated egg shell calcium challenge test.
Conclusion: These results indicate that there is little contamination of egg white in non-calcinated egg shell calcium, and that the allergenic activity of non-calcinated egg shell calcium is equivalent to that of calcinated egg shell calcium.