CROSS-REACTIVITY BETWEEN IGE-BINDING PROTEINS FROM ANISAKIS, GERMAN-COCKROACH, AND CHIRONOMIDS

Anisakis simplex larvae parasitize animals used as seafood and can pro duce a specific immune response in man. The ingestion of seafood conta minated with stage three of A. simplex larvae can induce a specific Ig E response with clinical symptoms, usually urticaria, even If the fish is cooked before ingestion and the invasive infestation power destroy ed by heating. Our preliminary studies showed a strong association of A. simplex sensitization with Ascaris lumbricoides, Daphnia, chironomi d spp., Atlantic shrimp (Pandalus borealis), and German cockroach (Bla ttella germanica). We conducted the cross-reactivity study with cockro ach, a ubiquitous insect, and Chironomidae (red mosquito larvae), a wo rk-related allergen, without any possibility of Anisakis contamination . Serum samples were collected from 60 pediatric patients, with serum specific IgE to A. simplex. Both specific-IgE and immunoblot-inhibitio n studies, with a serum pool from 18 patients, were performed to deter mine whether the association of sensitizations to nematodes and arthro pods was due to immunologic cross-reactivity. In addition, serum sampl es from 21 of 60 patients who showed also sensitization to German cock roach were used for individual immunoblot studies. In the serum pool, dose-dependent inhibition of B. germanica and Chironomus spp, was obse rved after preincubation with the A. simplex extract. Immunoblot of An isakis, inhibited with Chironomus and German cockroach, yielded a part ial blot inhibition but mainly on bands below 41 kDa. Blot inhibition of German cockroach and Chironomus with Anisakis was dose related. The band patterns in individual blots were heterogeneous, but most of the m had bands of 30-43 kDa. None of these sera recognized allergens in t he 14-kDa area. In our study, CAP-inhibition and immunoblot-inhibition analysis of Anisakis showed that several IgE-binding components could be shared by the three allergens.