Expression levels of parvalbumins determine allergenicity of fish species.
BACKGROUND
Parvalbumins are the most important fish allergens. Polysensitization to various fish species is frequently reported and linked to the cross-reactivity of their parvalbumins. Studies on cross-reactivity and its association to the allergenicity of purified natural parvalbumins from different fish species are still lacking. In addition, some studies indicate that dark muscled fish such as tuna are less allergenic.


METHODS
Total protein extracts and purified parvalbumins from cod, whiff, and swordfish, all eaten frequently in Spain, were tested for their IgE-binding properties with 16 fish allergic patients' sera from Madrid. The extent of cross-reactivity of these parvalbumins was investigated by IgE ELISA inhibition assays. Additionally, the cDNA sequences of whiff and swordfish parvalbumins were determined.


RESULTS
Extractable amounts of parvalbumins from cod were 20 times and from whiff 30 times higher than from swordfish. Parvalbumins were recognized by 94% of the patients in extracts of cod and whiff, but only by 60% in swordfish extracts. Nevertheless, a high cross-reactivity was determined for all purified parvalbumins by IgE inhibition. The amino acid sequence identities of the three parvalbumins were in a range of 62-74%.


CONCLUSIONS
The parvalbumins of cod, whiff and swordfish are highly cross-reactive. The high amino acid sequence identity among cod, whiff and swordfish parvalbumins results in the observed IgE cross-reactivity. The low allergenicity of swordfish is due to the low expression levels of its parvalbumin.
Department of Pathophysiology, Center for Physiology, Pathophysiology and Immunology, Medical University of Vienna, Austria.
U
U
Griesmeier
S
S
Vázquez-Cortés
M
M
Bublin
C
C
Radauer
Y
Y
Ma
P
P
Briza
M
M
Fernández-Rivas
H
H
Breiteneder
D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000737:chemistry* / Q000276:immunology; D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002648:Child; D002675:Child, Preschool; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D029941:Fish Proteins / Q000737:chemistry / Q000276:immunology; D005399:Fishes / Q000276:immunology*; D005512:Food Hypersensitivity / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D007223:Infant; D008297:Male; D010320:Parvalbumins / Q000737:chemistry* / Q000276:immunology; D055815:Young Adult
D000485:Allergens; D029941:Fish Proteins; D010320:Parvalbumins; D007073:Immunoglobulin E