characterization of specific ige antibody related to antigen 5 of echinococcus granulosus

background: anaphylactic reactions, such as urticaria, edema, respiratory symptoms, and anaphylactic shock often complicate the course of cystic echinococcosis (ce). methods: to investigate the role of the ige immunoreactive antigen 5 (ag 5) in the sero-positive patients with ce, we determined n-terminal of 57 kda subunit of ag5 responsible for ige and c-terminal of this active antigen related to induction of igg specifically. results: immunoblotting analysis showed that specific ige to 57-kda subunit related to inter-chain disulphide band of two 22 kda and 38-kda component of ag5 and conformational epitope on this subunits. in addition, since the 57 kda component arise from the removal of the c-terminal portion of 22 kda subunit of ag5, thus ige specifically recognized n-terminal of 22 kda subunit which remain bounds to the other component, whereas igg reacted with c-terminal of 38 kda component of ag5. conclusion: recognition of the specific binding site on the 57 kda subunit of ag5 could leads to understanding the mechanism regulating ige/igg production in some immune circumstances that ige tends to some dominate, whereas in other igg predominates.