A multiplex diagnostic test: exploring IgE sensitization to tropomyosins and related sea foods and arthropods
Alessandri C, Giangrieco I, Tuppo L, Bernardi ML, Zennaro D, Ferrara R, Rafaiani C, Ciancamerla M, Tamburrini M, Ciardiello MA, Mari A
Allergy 72: 666-666. (2017)
Introduction:Tropomyosins are allergenic proteins present ininvertebrate muscle and non-muscle cells, involved in muscle con-traction together with actin and myosin. A great number of aller-genic tropomyosins have already been described in invertebrate(crustaceans, molluscs, snails, mites, insects) whose IgE cross-reactiv-ity is related to the high structural similarity in amino acidsequences. The test is a new nanobead-based IVD test for specificIgE detection using 122 molecular allergens and 122 allergenicextracts, all coupled to chemically activated nano-particles.Objectives:To analyze the sensitization profiles of tropomyosinsensitized patients by means of the multiplex test, considering aller-genic molecules and extracts from crustaceans and mollusks.Results:The tested allergenic preparations, all immobilized on thechip, were 10 invertebrate extracts (Anisakis pegreffi, Anisakis sim-plex, calamari, clam, German and American cockroach, mussel, octo-pus, shrimp, snail), and seven tropomyosins (Ani s 3, Der p 10, Hel as 1, Lit v 1, Per a 7, Uro du 1, Ven ga 1). Out of the 1751 analyzedpatients 115 (6.58%) turned out to be sensitized to at least one ofthe 17 tested allergenic preparations. The most recognized extractwas clam with 36% prevalence, the least recognized is Americancockroach with 5% prevalence. The most recognized tropomyosin isVen ga 1 with 29% prevalence, the least recognized is Hel as 1 with20% prevalence. The patients recognizing at least one of the seventropomyosins are 49, 33% of them having IgE to all seven tropomyo-sins, 16% of them recognizing one only.Conclusions:The study results confirm differences in sensitizationpatterns toward the tested invertebrates extracts and tropomyosins.The single patient defined IgE profile, supported by clinical data andoral food challenge if needed, might lead to a better selection ofwhich of the involved foods should be excluded from the diet. Any-how, highly similar tropomyosins seems to behave in a patient-related manner. Food and non-food extracts from allergenic sourceswith known or still unknown tropomyosins help to broad the IgEprofile definition. Testing extracts from vertebrate species and fishesseems not to bring evidence of any IgE cross-reactivity.
