A comprehensive review on biological properties of fish and shellfish allergens

Seafood allergens, primarily derived from fish, crustaceans, and mollusks, represent a complex clinical challenge. The WHO/IUIS Allergen Nomenclature Sub-committee has cataloged over 80 allergens classified into 18 protein families, with Arthropoda (48 allergens), Chordata (26), and Mollusca (9) serving as the major contributors. Notably, most allergens exhibit cross-species conservation, being identified in multiple seafood types—a feature that predisposes individuals to cross-reactivity due to their ubiquitous presence in living organisms. This complexity is further exacerbated by the evolutionary divergence among seafood taxa and their intricate phylogenetic relationships with mites and insects, creating significant hurdles for precise clinical allergen diagnosis. A comprehensive understanding of seafood allergens is therefore essential, encompassing both their cross-reactive potential across species and the molecular basis of allergenicity. This review systematically examines seafood allergens through the lens of protein biochemistry, detailing their discovery history, physiological functions, structural characteristics, stability profiles, and immunogenic cross-reactivity. While shellfish-dust mite cross-reactivity is well-documented, emerging evidence suggests similar phenomena involving other arthropods, including insects like cockroaches. To elucidate these cross-reactive mechanisms, we conduct a comparative analysis of protein similarities among crustaceans, insects, and mites, aiming to identify shared epitopes and molecular determinants that drive allergic responses. Clinical Trial Number: not applicable.