A randomized, double-blinded, placebo-controlled oral challenge study to evaluate the allergenicity of commercial, food-grade fish gelatin.
BACKGROUND
Recent interest in the labeling of foods and food proteins derived from allergenic sources necessitates determination of the potential allergenicity of such food ingredients. Fish gelatin is extracted from the skin of fish species known to elicit allergic reactions in sensitized individuals.


OBJECTIVE
To determine the allergenicity of fish gelatin by double-blinded, placebo-controlled food challenges (DBPCFC) in clinically fish-allergic individuals.


METHODS
Thirty fish-allergic patients diagnosed according to the EAACI Guidelines were included (age 9-50 years). Skin prick tests (SPT) and Histamine Release tests (HR) were performed with fish gelatin and codfish, and codfish-specific IgE was measured. All patients underwent DBPCFC with a cumulative dose of 14.61 g fish gelatin.


RESULTS
In all 30 patients SPT, HR, and specific IgE to codfish were positive. SPT and HR with fish gelatin were positive in 3/30 and 7/30, respectively. One patient showed mild reaction to placebo and no reaction to the active challenge. Two patients reported mild subjective reactions to active challenge. Upon re-challenge one of them described subjective symptoms again to the active challenge (7.61 g cumulated dose of fish gelatin) with no reaction to placebo, while the other experienced very mild subjective symptoms to placebo and nothing to the active. The proportion of truly sensitive patients was estimated to 0.03 in the total study group.


CONCLUSIONS
None of 30 fish allergic patients reacted adversely to the ingestion of 3.61 g cumulative dose of fish gelatin. In this study fish gelatin presents no risk to fish-allergic patients at the doses typically used. Statistically, these results indicate that there is 95% certainty that 90% of fish-allergic consumers will not react to ingestion of a 3.61 g cumulative dose of fish gelatin.
Hansen
Tine K
TK
Allergy Center, Odense University Hospital, Sdr. Boulevard 29, DK-5000 Odense C, Denmark. tinekh@dadlnet.dk
Poulsen
Lars K
LK
Stahl Skov
Per
P
Hefle
Susan L
SL
Hlywka
Jason J
JJ
Taylor
Steve L
SL
Bindslev-Jensen
Ulla
U
Bindslev-Jensen
Carsten
C
D000293:Adolescent; D000328:Adult; D000818:Animals; D002648:Child; D004311:Double-Blind Method; D005189:False Positive Reactions; D005260:Female; D005399:Fishes; D005512:Food Hypersensitivity / Q000175:diagnosis*; D005780:Gelatin / Q000009:adverse effects*; D006636:Histamine Release / Q000187:drug effects; D006801:Humans; D007073:Immunoglobulin E / Q000096:biosynthesis; D008297:Male; D008460:Meat / Q000009:adverse effects*; D008875:Middle Aged; D015233:Models, Statistical; D012867:Skin / Q000737:chemistry; D012882:Skin Tests
D007073:Immunoglobulin E; D005780:Gelatin