090 - Component Resolved Diagnosis (CRD): in-vitro definition of allergic patient’s profile
Autor(s): B. Caruso, A. Ferrari, N. Melloni, M. Rocca, D. Nicolis, C. Cocco, P. Rizzotti
Issue: RIMeL - IJLaM, Vol. 5, N. 3-S1, 2009 (MAF Servizi srl ed.)
Page(s): 90-95
Summary
Molecular characterization of IgE reactivity of specific individual components of allergenic extracts is now possible due to the technology of recombinant allergens derived from studies of molecular biology of allergic pathology. The identification of the immunoreactivity to single allergenic components in allergic individuals allows to specifically define her/his allergic profile and obtain the so-termed Component Resolved Diagnosis (CRD). Molecular allergens can be classified into those that induce the respiratory allergic reactivity and those that identify the food-related allergic pathology. It is also essential to identify those molecular allergens whose immunoreactivity is able to connect the two clinical conditions: respiratory symptoms and food allergic symptoms. Proteins intervening in the defence system of plants belonging to the group of Pathogenesis-Related proteins (PR- 10) are the best characterized molecules in the recent years. Within the Pr-10 group of allergens, Bet v 1, the major allergen from birch pollen, is responsible not only for allergic respiratory reactions but also for food allergic reactions (Oral Allergy Syndrome - SOA). The family of profiline is another well characterized group of molecular allergens, which includes Bet v 2 (birch profiline), whose allergic immunoreactivity is also responsible for more than one allergic symptom. Interestingly, response to immunotherapy can be predicted from immunoreactivity. For instance, in the case of IgE reactivity to grass pollen, subjects positive to Phl p 1 (protein “Beta-Expansin”) and Phl p 5 (ribonuclease) and negative to Phl p 7 (PR-10 of grass and cross-reactive with Bet v1) and to Phl p 12 (profiline of grass and crossreactive with Bet v 2) seem to respond better to the vaccine. Moreover, the availability of the first recombinant Phl p 5 vaccines suggests to characterize properly the IgE response to this molecular antigen. As for the sensitisation to flour food, whose vegetal origin is still belonging to the grasses we should consider the syndrome of Wheat-Dependent Exercise-induced Anaphylaxis (WDEIA) that would be defined by allergic immunoreactivity to the omega-5 gliadin molecule. Another series of molecules that connect vegetal world both of pollen and of food origin are the Lipid Transfer Protein, whose allergenic reactivity would also be responsible for severe symptoms. In conclusion, understanding the relationship between allergic symptoms and the profile of immunoreactivity to the molecular components of an allergen in each individual is therefore crucial.
Key-words: Component Resolved Diagnosis, Molecular Allergens, Immunoreactivity profile, Pathogenesis-related proteins (PR-10), Birch Profiline ( Bet v 2), Wheat-dependent Exercise-induced Anaphylaxis (WDEIA).