Monospecific allergy to swordfish.
BACKGROUND
Fish allergy is a relatively common and potentially fatal condition. Most fish allergic subjects are allergic to multiple fish species. We encountered a patient clinically allergic only to swordfish.


OBJECTIVE
To characterize the in vivo and in vitro IgE antibody responsiveness of this patient solely allergic to swordfish.


METHODS
Prick skin tests, as well as immunoassay and protein immunoblotting for IgE antibody were performed using commercial fish extracts and fresh swordfish. A more typical multiple fish-allergic subject and a subject not allergic to food were also studied for comparison.


RESULTS
The multiple fish-allergic subject demonstrated IgE antibody to a 13-kD protein in all fish tested (probably Gad c 1 and its analogues in other fish). The swordfish-allergic subject did not recognize this 13-kD band but did demonstrate IgE directed against a 25-kD band only in swordfish. The negative control showed no IgE binding to either the 13 or 25 kD bands.


CONCLUSIONS
It is possible to be allergic to a single fish species, such as swordfish, and such monospecific allergy may be due to the presence of species-specific allergens, in this case a 25-kD allergen in swordfish.
Kelso
J M
JM
Department of Internal Medicine (Allergy Division), Naval Medical Center, San Diego, California, USA.
Jones
R T
RT
Yunginger
J W
JW
D000328:Adult; D000818:Animals; D005399:Fishes / Q000276:immunology*; D005512:Food Hypersensitivity / Q000209:etiology*; D006801:Humans; D008297:Male