f3 Cod

Allergens within Food of Animal Origin

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  • Latin name: Gadus morhua
  • Family: Gadidae
  • Source material: Fish muscle
Patients allergic to fish often have dramatic symptoms, such as asthma or anaphylactic reactions. Some patients allergic to one fish may tolerate other fish species.

Allergen Exposure

Meat from cod.
Cod is sold fresh, frozen, smoked, salted or canned.
 
Unexpected exposure
Undeclared ingredient in industrially prepared food, such as cured meat products.
Contamination of cooking oil, utensils and containers.
Inhalation of  steam or dried fragments.

Potential Cross-Reactivity

Species within groups of fish, like Gadiformes (examples: codfish and hake) and Scombroid fishes (examples: mackerel and tuna) seem to share allergenic components. The overlap of allergen specificity between the groups seems to be moderate or even small.

Clinical Experience

IgE-mediated reactions
Sensitization to fish allergen is common. Prevalence figures vary from approx. 10% to approx. 40% in atopic populations. In Norway fish allergy was found in 1/1000 of the general population.

Reactions on fish allergens are often severe. Systemic reactions after eating fish, but also after inhaling steam or aerosol in connection with cooking or handling fish, or after skin contact, are reported in several studies.
 
Review
The Atlantic cod is one of the world’s most important food fish. It is sold fresh, frozen, smoked, salted or canned. Patients allergic to fish often have dramatic symptoms and severe asthmatic attacks can be triggered by the smell of fish. Extremely sensitive patients have suffered anaphylactic shock after eating foods cooked in re-used cooking oil, or when utensils and containers have been used earlier for cooking fish. Many patients avoid all species of fish and others may tolerate a few, thus indicating specific allergens. The cod family, Gadidae, contains many important species, only some of which are mentioned in Fig. 3. Several are internationally marketed as frozen fish meat under a variety of names. Walleye pollock (Theragra chalcogramma) is a major constituent of surimi. Cross-reactions should be expected.
 
The allergen Gad c 1 (allergen M) from cod was the first allergen to be isolated as a pure fraction (1). Its current name is derived from an old obsolete name for G. morhua. It is a calcium-binding protein belonging to the parvalbumins found only in the muscle tissue of fish and amphibians. In addition to Gad c 1, codfish contains a wide range of IgE-reactive proteins in the molecular weight range 12-130 kD (2). Some codfish sensitive patients seem to have IgE antibodies capable of binding also to similar proteins in some other species (3). An IgE-binding protein of similar size was found in catfish and snapper but not in tuna (4). Because patients react to both cooked and raw fish, it is assumed the allergens are heat-resistant. However, more recent studies indicate that patients may react differently to processed food (5) and that allergic reactions may be species-specific (6, 7).
 
In a group of Italian children with food allergy, about 18% had IgE antibodies to cod and two-thirds had clinical manifestations upon inhalation or ingestion of the fish (7). A fatal anaphylactic reaction occurred in a fish-allergic patient who ate fried potatoes cooked in the same oil used for fish (8). Because of good correlation between reactions in in vivo and in vitro tests, it has been suggested that food challenges are not necessary (9). The clinical sensitivity and specificity of Pharmacia CAP System™ f3 Cod was reported to be 93% and 87%, respectively (10).
 
In an American study on catfish, bass, perch, mackerel (Rf206), tuna (f40), salmon (f41), trout (f204), cod (f3), flounder and sardine (Rf308) among other species, it was found that patients allergic to one fish may tolerate other fish species (6). This confirmed the results of an Italian study on codfish-sensitive children including also eel (Rf 364), anchovy (Rf 313), sole (Rf 337), and other species (7).

References:

    1. Elsayed, S; Aas, K. Isolation of purified allergens (cod) by isoelectric focusing. Int Arch Allergy appl Immunol; 1971; 40: 428-438.
    2. Dory, D; Chopin, C; Aimone-Gastin, I; Gueant, JL; Guerin, L; Sainte-Laudy, J; Moneret-Vautrin, DA; Fleurence, J. Recognition of an extensive range of IgE-reactive proteins in cod extract. Allergy; 1998; 53: 42-50.
    3. Hansen, TK; Bindslev-Jensen, C; Stahl Skov, P; Poulsen, LK. Codfish allergy in adults: IgE cross-reactivity among fish species. Ann Allergy Asthma Immunol; 1997; 78: 187-194.
    4. James, JM; Helm, RM; Burks, AW; Lehrer, SB. Comparison of pediatric and adult IgE antibody binding to fish proteins. Ann Allergy Asthma Immunol; 1997; 79: 131-137.
    5. Bock, SA. Natural history of severe reactions to foods in young children. J Pediatrics; 1985; 107: 676-680.
    6. Bernhisel-Broadbent, J; Scanlon, SM; Sampson, HA. Fish hypersensitivity. J Allergy Clin Immunol; 1992; 89: 730-737.
    7. Elsayed, S; Aas, K. Isolation of purified allergens (cod) by isoelectric focusing. Int Arch Allergy appl Immunol; 1971; 40: 428-438.
    8. Helbling, A; McCants, ML; Musmand, JJ; Schwartz, HJ; Lehrer, SB. Immunopatho-genesis of fish allergy: identification of fish-allergic adults by skin test and radio-allergosorbent test. Ann Allergy, Asthma Immunol; 1996; 77: 48-54.
    9. Hansen, TK; Skov, PS; Bindslev-Jensen, C. Codfish allergy in adults. Schweiz med Wschr; 1991; 121 (Suppl 40): 82.
    10. Hansen, TK; Bindslev-Jensen, C; Stahl Skov, P; Poulsen, LK. Codfish allergy in adults: IgE cross-reactivity among fish species. Ann Allergy Asthma Immunol; 1997; 78: 187-194.

1999



Further Reading