ABSTRACT
BACKGROUND: Our group previously found that up to 7% of amateur anglers in Caceres, Spain may be allergic to the larvae of Protophormia terraenovae (order Diptera, family Calliphoridae) used as live bait for fishing. OBJECTIVE: To identify the pattern of major allergens in P terraenovae and other species of Calliphoridae. MATERIALS AND METHODS: Extracts of P terraenovae, Calliphora vomitoria, Lucilia sericata and Lumbricus terrestris were characterized using sodium dodecyl sulfate polyacrylamide gel electrophoresis and IgE-immunoblotting techniques in individual sera from 24 patients with a positive skin test result and/or specific IgE determination (enzyme-linked immunosorbent assay [ELISA]) to P terraenovae. ELISA and IgE-immunoblotting inhibition studies were also performed to identify potential cross-reactive allergens between these species. RESULTS: IgE-immunoblotting with P terraenovae showed a band of 15.3 kDa recognized by 15 patients, in addition to 2 further allergens of 22.8 kDa and 69 kDa. For C vomitoria, 5 bands of 73, 46, 40, 28, and 14 kDa were observed. For L sericata, 2 major allergens of 73 kDa and 14 kDa were observed. In the case of L terrestris, IgE from 13 patients recognized 1 allergen of around 15.5 kDa. IgE-immunoblotting and ELISA inhibition revealed the presence of cross-reactivity, mainly between L terrestris and P terraenovae. CONCLUSIONS: P terraenovae appears to have species-specific allergens and allergens shared with C vomitoria and L sericata. Striking immunological cross-reactivity was observed between P terraenovae and L terrestris. An allergen of 15-16 kDa could be involved in this phenomenon.
