Clinically Significant Cross-Reactivities among Allergens

Crossreactivity of IgE antibodies are occasionally unexpected and confusing. Moreover, the implications are not always the same. Some types of serologic crossreactivities usually produce clinical symptoms, whereas other do not. Even the latter type may be relevant, as it may contribute to the induction of immune responses to the crossreactive antigens ('crossreactive priming'). For the interpretation of IgE antibody assays it is important to appreciate that finding IgE antibodies to some allergen does not imply that the patient has ever been exposed to that allergen.