Identification and characterization of novel allergen candidates in blood clams (Anadara broughtonii and Tegillarca granosa) using proteomics and immunoinformatics.

Blood clams (Anadara broughtonii and Tegillarca granosa) are widely consumed in Southeast Asia and can trigger allergic reactions. Whereas tropomyosin and arginine kinase are established allergens, the broader allergen profile and cross-reactivity with shrimp remain poorly defined. Using gel and LC-MS-based proteomics, a novel immunoinformatic approach combining three algorithms and IgE immunoassays, we examined IgE-reactivity in shrimp-sensitized patients. Among 2580 identified proteins, 35 were from blood clams, while 9 were predicted as allergens. From IgE-reactive 2D gel spots, known allergens tropomyosin and arginine kinase were identified, and 17 novel candidate allergens were predicted, including HSP90, ferritin, and hemoglobin-Hb1. Furthermore, MHC and alpha-actinin from IgE-reactive spots were identified as abundant myofibrillar scaffold proteins lacking IUIS-registered homologues. Overall, 35% of sera reacted to blood clam proteins, with strong ELISA correlations to blue mussels. These findings expand the allergen repertoire of blood clams and highlight new candidates for food allergen risk assessment.