Allergenicity of bony and cartilaginous fish – molecular and immunological properties

Abstract

Allergy to bony fish is common and probably increasing world-wide. The major heat-stable pan-fish allergen, parvalbumin (PV), has been identified and characterized for numerous fish species. In contrast, there are very few reports of allergic reactions to cartilaginous fish despite widespread consumption. The molecular basis for this seemingly low clinical cross-reactivity between these two fish groups has not been elucidated. PV consists of two distinct protein lineages, α and β. The α-lineage of this protein is predominant in muscle tissue of cartilaginous fish (Chondrichthyes), while β-PV is abundant in muscle tissue of bony fish (Osteichthyes). The low incidence of allergic reactions to ingested rays and sharks is likely due to the lack of molecular similarity, resulting in reduced immunological cross-reactivity between the two PV lineages. Structurally and physiologically, both protein lineages are very similar; however, the amino acid homology is very low with 47-54%. Furthermore, PV from ancient fish species such as the coelacanth demonstrates 62% sequence homology to leopard shark α-PV and 70% to carp β-PV. This indicates the extent of conservation of the PV isoforms lineages across millennia. This review highlights prevalence data on fish allergy and sensitization to fish, and details the molecular diversity of the two protein lineages of the major fish allergen PV among different fish groups, emphasizing the immunological and clinical differences in allergenicity.

A patient‐specific approach to develop an exclusion diet to manage food allergy in infants and children

“…Nutritionally, fish is a rich source of protein and oily fish contributes essential long-chain polyunsaturated fatty acids to the diet. 90 Fish and shellfish allergies may coexist. 87,88 This is because, although the most common fish allergen is b parvalbumin, there are several fish allergens, and the predominant allergen varies between individual fish species.…”

“…87,88 This is because, although the most common fish allergen is b parvalbumin, there are several fish allergens, and the predominant allergen varies between individual fish species. 89,90 In addition, there is large regional variation in the predominant species of fish consumed, 89 and as skin prick testing reagents do not exist for all fish, food challenges to individual fish may be considered. More studies to inform clinical management are still required in this area.…”

“…More studies to inform clinical management are still required in this area. 90 Fish and shellfish allergies may coexist. 91 However, clinical crossreactivity between fish and shellfish is uncommon as the major allergen in shellfish is tropomyosin.…”

Developments in the field of allergy in 2017 through the eyes of Clinical and Experimental Allergy

“…33 We also have an improving understanding of the allergens that induce allergy reactions to foods as exemplified by Sharp and colleagues review on fish allergens. 34 It also seems that there are specific patterns or phenotypes of food allergy. 35 Finally, Stensgaard and colleague have demonstrated the major impact that food allergy has on the whole family.…”

Reconstruction of fish allergenicity from the content and structural traits of the component β-parvalbumin isoforms

“…The major allergen of fish has been identified as β-parvalbumin (β-PV), a Ca 2+ -binding acidic protein that is abundant in muscle 3,4,5,6,7 . Most allergic patients react to more than one fish species due to the cross-reactivity of their β-PV chains, but despite the presence of anti-β-PV, IgE often tolerates a variety of species 8,9,10,11,12 . The tolerance of cartilaginous fish results from the absence of cross-reactivity of the basic α-lineage of the expressed PV 12 .…”