Introduction:
The progressive advance in the knowledge and characterization of
allergenic molecules responsible for allergic sensitization to most
sources have had a profound impact in the etiological management of
allergic disease. This impact can be summarized in three main aspects.
Firstly, it has profoundly transformed the way allergenic extracts are
characterized and standardized which is legally reflected in the
regulatory framework for allergens, especially on the Note for Guidance
on Allergenic Extracts, issued by the European Medicine Agency (EMA) and
on the allergen monograph of the European Pharmacopoeia, issued by EDQM
(Council of Europe), that is adopted by European Directives for
Medicinal products 1-3.
Secondly, it improved the accuracy of allergy diagnosis. Single or
multiplexed, allergenic molecules are routinely used and have changed
the way we diagnose 4.
Lastly, but not least, some sensitization profiles are linked to
different clinical phenotypes, and can be used to stratify allergic
patients, to predict intervention outcomes, and to perform system
biology studies that open new avenues for allergy disease management5-11.
The implementation of a new regulatory framework led to the
commercialization of allergy vaccines with registration clinical trials
performed during five years. Based on these studies, a better
understanding of AIT mechanisms is now possible. From allergen-specific
effector cell desensitization5,12-14to a progressive onset of T and B cell-mediated regulatory mechanisms15-19 responsible for
the disease-modifying effect, their temporal alignment is critical to
establish best AIT practices. In this context, the quality of the
extract used − and its standardization −, the knowledge of patient’s
sensitization profiles, and the link to the AIT product used are pivotal
to maximize the odds of AIT success. In this review, we discuss the
different aspects of molecular allergology, from an overview of
allergenic molecules and diagnostic methods to the quality of allergen
preparation and the clinical approaches to AIT. We aim to offer a
practical document to support the allergy specialist in the daily
clinical management of allergic patients.