Allergen profile of Protophormia terraenovae, other species of calliphoridae, and Lumbricus terrestris in anglers allergic to maggots in Cáceres, Spain

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. To identify the pattern of major allergens in P terraenovae and other species of Calliphoridae. 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. 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. 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.