title: Oral inoculation of live or dead third-stage larvae of Anisakis simplex in rats suggests that only live larvae induce production of antibody specific to A. simplex.
abstract: Live Anisakis simplex third-stage larvae (L3) penetrate gastrointestinal mucosa after they are ingested in raw or undercooked seafood, thereafter causing gastrointestinal manifestations and allergic manifestations such as urticaria and anaphylaxis. These allergic reactions are mediated by specific IgE to L3 allergens, especially excretory-secretory (ES) allergens. Recent evidences suggest that only live larvae can cause allergic reactions, although cases attributable to ingestion of cooked, frozen seafood have been reported. Therefore the risk of Anisakis-associated hypersensitivity by ingestion of properly cooked and frozen fish remains controversial. No prior report describes the kinetics of antibody production in experimental animals after oral inoculation with dead L3. This study used ELISA to assess antibody production in rats inoculated orally with dead L3. Positive absorbance value in IgG, IgM, and IgE specific to ES antigen from L3 were found in rats inoculated with live L3 but not with dead L3 (frozen, heated, cut, or homogenized). At one week post re-inoculation with live or frozen L3 to the initially sensitized rats, the absorbance value of the specific IgM and IgE to ES antigen elevated quickly and highly in rats that had been re-inoculated with live L3, but they decreased slightly or did not change in rats inoculated with frozen L3. These results suggest that only ingestion of live L3 can produce the specific antibody and induce initial and secondary sensitizations to L3.
authors.affiliation: Department of Microbiology, Osaka City Institute of Public Health and Environmental Sciences, Tennoji-ku, Osaka, 543-0026, Japan, niichiro@gmail.com.
authors.forename: Niichiro
authors.initials: N
authors.lastname: Abe
authors.forename: Isao
authors.initials: I
authors.lastname: Teramoto
mesh_terms: D000818:Animals; D017163:Anisakis / Q000276:immunology*; D000909:Antibodies, Helminth / Q000097:blood / Q000276:immunology*; D000918:Antibody Specificity; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007814:Larva / Q000276:immunology; D051381:Rats
chemical_list: D000909:Antibodies, Helminth; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007073:Immunoglobulin E