Tropomyosin is a cross-reactive allergenic protein present in arthropods and is ingested or inhaled in an occupational setting. Exposure and sensitisation via the inhalation route is particularly important in the seafood processing industry where workers are continuously exposed to the aerosolised form of this major food allergen. The aim of this study was to develop the first antibody-based immunoassay to enable the specific quantification of aerosolised invertebrate tropomyosin present in the environment of the shellfish processing industry.

Anti-tropomyosin antibody was generated in rabbits against a combination of tropomyosin from four crustacean species and immuno-affinity purified to be applied in the capture system. Recombinant tiger prawn tropomyosin was generated in E. coli and used for the immune-affinity purification of the generated antibodies and as allergen standard. In order to quantify aerosolised tropomyosin, air collection was performed in the personal breathing zone of 80 workers in edible and king crab processing factories, using PTFE filters. The purified antibody selectively detected tropomyosin from crustacean but not from fish or chicken. The limit of detection (LOD) for the developed sandwich ELISA was 60 picogram/ m3 and limit of quantitation (LOQ) 100 picogram/m3. Immunoassay validation was based on linearity (R2 0.999), matrix interference test (78.8% ± 6.5%), intra-assay CV (9.8%) and inter-assay CV (11%). The novel immunoassay was able to successfully identify working activities, which generate low, medium and high concentrations of the aerosolized food allergen.

We describe the first antibody-based immunoassay for the highly sensitive and specific quantification of the major food allergen tropomyosin. This novel immunological approach can be modified for the detection of other aerosolized food allergens, assisting in the identification of high-risk allergen exposure areas.