Identification of crab proteins that elicit IgE reactivity in snow crab-processing workers.
BACKGROUND
The expanding snow crab-processing industry has resulted in increased numbers of workers at risk of occupational allergy.


OBJECTIVE
Our study is to identify relevant allergenic proteins in cooked snow crab meat (CM) and crab water (CW) used for cooking for improved remediation, diagnosis, and treatment.


METHODS
Extracts were prepared from CM extracts, CW extracts, and an air-filter collection near the crab cooker. Of the 207 workers, 24 with the highest IgE antibody reactivity to CM and CW extracts, as determined by using RASTs, were tested for reactivity to nitrocellulose membranes containing CM and CW proteins separated with SDS-PAGE. A 3-serum pool was similarly incubated against nitrocellulose-bound proteins from air samples collected near the crab cooker.


RESULTS
Of the 207 sera tested, 27 and 39 sera exhibited positive IgE antibody reactivity (>or=2%) to CM and CW extracts, respectively. Twenty-two of 24 sera with the highest RAST activity (>or=3.5% binding) demonstrated IgE binding to multiple proteins (13.6-50 kd). A majority of the sera reacted to 4 proteins: 79% and 71% to a 34.0-kd protein, 79% and 42% to a 25-kd protein, 67% and 71% to an 18.5-kd protein, and 75% to a 14.4-kd protein in both CM and CW extracts, respectively. The pool of IgE-positive sera blotted against the air-filter extract reacted to 14.4-, 18.5-, 34.0-, 43.2-, and 50-kd proteins present in both crab extracts.


CONCLUSIONS
Four major IgE-reactive proteins were identified in CM extracts, CW extracts, and air-filter eluate. Analysis of any potential association of protein reactivity with disease suggested crab proteins at 34.0 and 14.4 kd might be more relevant.
Gill
Beth V
BV
Department of Medicine, Section of Clinical Immunology, Tulane University Health Sciences Center, New Orleans, LA 70112, USA.
Rice
Timothy R
TR
Cartier
André
A
Gautrin
Denise
D
Neis
Barbara
B
Horth-Susin
Lise
L
Jong
Michael
M
Swanson
Mark
M
Lehrer
Samuel B
SB
D000485:Allergens / Q000276:immunology* / Q000302:isolation & purification; D000818:Animals; D003386:Brachyura / Q000276:immunology*; D005525:Food-Processing Industry; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology* / Q000378:metabolism; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology*; D009784:Occupational Diseases / Q000276:immunology; D011506:Proteins / Q000276:immunology* / Q000302:isolation & purification
D000485:Allergens; D011506:Proteins; D007073:Immunoglobulin E