Fish Allergens at a Glance: Variable Allergenicity of Parvalbumins, the Major Fish Allergens

Abstract

Fish is a common trigger of severe, food-allergic reactions. Only a limited number of proteins induce specific IgE-mediated immune reactions. The major fish allergens are the parvalbumins. They are members of the calcium-binding EF-hand protein family characterized by a conserved protein structure. They represent highly cross-reactive allergens for patients with specific IgE to conserved epitopes. These patients might experience clinical reactions with various fish species. On the other hand, some individuals have IgE antibodies directed against unique, species-specific parvalbumin epitopes, and these patients show clinical symptoms only with certain fish species. Furthermore, different parvalbumin isoforms and isoallergens are present in the same fish and might display variable allergenicity. This was shown for salmon homologs, where only a single parvalbumin (beta-1) isoform was identified as allergen in specific patients. In addition to the parvalbumins, several other fish proteins, enolases, aldolases, and fish gelatin, seem to be important allergens. New clinical and molecular insights advanced the knowledge and understanding of fish allergy in the last years. These findings were useful for the advancement of the IgE-based diagnosis and also for the management of fish allergies consisting of advice and treatment of fish-allergic patients.

Immunological cross-reactivity between four distant parvalbumins—Impact on allergen detection and diagnostics

“…Parvalbumin, the major allergen from fish is a diverse protein that is expressed in many forms in different fish species (Kuehn et al, 2014;Lopata and Lehrer, 2009;. Table 2 Analysis of raw and heated extracts from the indirect ELISA, ticks represent greater binding to raw, heated, no difference (neutral) or negative binding.…”

“…Parvalbumin, a small calcium binding protein, is the major allergen identified in most fish species (Arif, 2009;Kuehn et al, 2014;. Parvalbumins range between 10 and 15 kDa in size and have low isoelectric points ranging from 3.5 to 5.…”

Seafood Allergy, Toxicity, and Intolerance: A Review

“…On the other hand, some individuals showed clinical monosensitivity to a single fish or fish family [43,44]. Interestingly, selective allergy to fish of the Salmonidae family (salmon and rainbow trout) was associated with parvalbumin isoforms of variable allergenicity [45]. Several studies examined the parvalbumin profile in dark and white muscle fish [40,46,47].…”

Authentication of closely related scombrid, catfish and tilapia species by PCR-based analysis and isoelectric focusing of parvalbumin

“…However, there are reports assigning a minor role of parvalbumin in the allergic reaction of some people against fish; other proteins, e.g. glycolytic enzymes and gelatin, have been identified as allergens in fish muscle [46]. The occasionally observed monosensitivity to pangasius and tilapia generates a health risk for the allergic persons concerned, if these species have been used as substitutes [56].…”

“…Parvalbumins, the major fish allergens, are present in high concentrations in the sarcoplasm of light muscle of many fish species [41][42][43][44][45][46]. Parvalbumins are characterized by a low molecular mass (10-12.5 kDa), pI values of 3.5-5.5, binding to Ca 2+ and Mg 2+ ions, which facilitates fast contraction-relaxation cycles in muscle and expression of different isoforms throughout the development of fishes [47].…”