title: Isolation and characterization of a major allergen from the fish parasite Anisakis simplex.
abstract: BACKGROUND
  Ingestion of raw or undercooked fish can lead to infection of human subjects by the fish parasite Anisakis simplex, a disease known as anisakiasis or anisakidosis. Patients sensitized to this fish parasite show high levels of total and specific IgE. Cross-reactions seem to explain the fact that specific IgE antibodies are also found in a high number of normal subjects, as reported in other parasitoses.
  
  
  OBJECTIVE
  We sought to purify and characterize a major IgE-binding protein from the parasite.
  
  
  METHODS
  A protein was purified from the crude parasite extract by means of ethanol precipitation and reversed-phase HPLC. Its clinical relevance was tested on 20 parasite-positive sera by using IgE and IgG4 immunoblotting. A monospecific human serum was used to study its localization in the parasite body.
  
  
  RESULTS
  A 24-kd protein was purified, to which only 45% of the sera had specific IgG4, but 85% of sera had specific IgE. The protein was present only in the excretory gland, as shown by immunohistochemistry. N-terminal amino acid sequence (17 residues) showed no homology to previously described proteins.
  
  
  CONCLUSIONS
  A simplex contains a potent allergen in the excretory gland. This major parasite allergen, named Ani s 1, could have important clinical relevance, as shown by the high number of positive sera in the specific IgE immunoblotting.
authors.affiliation: Centro de Investigación Clinica, Instituto de Salud Carlos III, and Hospital Ramón y Cajal, Madrid.
authors.forename: I
authors.initials: I
authors.lastname: Moneo
authors.forename: M L
authors.initials: ML
authors.lastname: Caballero
authors.forename: F
authors.initials: F
authors.lastname: Gómez
authors.forename: E
authors.initials: E
authors.lastname: Ortega
authors.forename: M J
authors.initials: MJ
authors.lastname: Alonso
mesh_terms: D000485:Allergens / Q000737:chemistry / Q000302:isolation & purification*; D000818:Animals; D017129:Anisakiasis / Q000276:immunology*; D017163:Anisakis / Q000737:chemistry* / Q000276:immunology; D002352:Carrier Proteins / Q000378:metabolism; D003429:Cross Reactions; D005393:Fish Diseases / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000378:metabolism
chemical_list: D000485:Allergens; D002352:Carrier Proteins; D007073:Immunoglobulin E