Allergenic extracts for specific immunotherapy: to mix or not to mix?

Immunotherapy for allergic diseases give rise to questions about when a decision must be taken to define the number of extracts to be used in a single treatment. This represents a long-lasting matter of debate between American and European allergists, which seems to be without real solution. Through the use of extract-based versus molecule-based diagnostic approaches we suggest a possible solution to this controversial issue. We used four model patients previously tested with allergenic extracts and later on selected on the basis of a panel of available allergenic molecules. Their reactivity patterns in term of extracts and molecules were compared and the decision for allergenic extract immunotherapy was made choosing either the 'classical' approach or the molecular approach. From our study it seems that molecules could offer the solution to the 'mixing' issue of allergenic extracts. This innovative approach seems to provide a solution for both the American and the European approach.