096 - What the Component Resolved Diagnosis cannot tell us yet
Autor(s): D. Villalta
Issue: RIMeL - IJLaM, Vol. 5, N. 3-S1, 2009 (MAF Servizi srl ed.)
Page(s): 96-99
Summary
Detection of the single molecules responsible for allergic reactions represents one of the major advances in recent years in the field of allergy diagnosis. In fact, the availability of such molecules, whether in native or recombinant form, has allowed the development of in vitro tests able to define the exact allergenic profile of each patient (Component Resolved Diagnosis-CRD), with important repercussions for clinical practice, such as the ability to distinguish between states of co-sensitization or cross-reactivity as well as the possibility of predicting the severity of reaction to any plant-based food. Despite such undeniable utility, CRD has some limitations. In some circumstances, it cannot completely replace diagnosis based on allergenic extracts. This is so in particular: (a) when the principal molecules responsible for the reaction to a specific allergen are no longer available in native or recombinant form; (b) when the principal molecules responsible for reaction to a specific allergen are not known; (c) when, although the principal molecules of a specific allergen are known and available for tests in vitro, the patient with symptoms suggestive of allergies nevertheless has negative results to molecular tests. In addition, CRD in its present state does not seem to be able to answer some clinical questions, in particular: (a) which patients with sensitization to Bet v1 may develop SOA toward fruit and/or vegetables? (b) which patients with food hypersensitivity are tolerant or symptomatic after ingestion of the food? and (c) when children with sensitivity to milk, eggs, or peanuts may outgrow their allergy? Only the double-blind placebo controlled oral food challenge (DBPCFC) - which is cumbersome and not without risk - is able to give results to such problems. However, microarrays which do not use the whole molecule but peptide sequences of the molecules (peptide microarray) are under development. The preliminary results of these are extremely interesting and, if confirmed, may pave the way to the use of such methods in clinical practice, especially in some childhood food allergies. They have the double advantage of avoiding DBPCFC while using the most limited amount of blood.
Key-words: allergy, component resolved diagnosis (CRD), microarray, peptide microarray.