Crawfish and lobster allergens: identification and structural similarities with other crustacea.

Antigenic and allergenic components in crawfish and lobster extracts were studied using crossed immunoelectrophoretic techniques. Crossed immunoelectrophoresis with rabbit antisera revealed 23 antigens in crawfish and 17 antigens in lobster extracts. Both extracts exhibited structural similarities in antigens mutually and with other crustacea in cross-line immunoelectrophoresis. Crossed radioimmunoelectrophoresis (CRIE) demonstrated 6 crawfish and 4 lobster allergens when individual or pooled sera from radioallergosorbent test (RAST)-positive crustacea-sensitive subjects were used. Since radiostaining was also observed with sera from RAST-negative nonsensitive subjects, specificity of IgE binding was tested using CRIE-inhibition. Preincubation of RAST-positive sera with crawfish or lobster extract decreased radiostaining in CRIE, while no changes occurred when using control sera. These results confirmed the presence of IgE-mediated mechanisms in seafood allergy and demonstrated a number of shared antigenic determinants among crustacea allergens.