title: Allergy to fish collagen: Thermostability of collagen and IgE reactivity of patients' sera with extracts of 11 species of bony and cartilaginous fish.
abstract: BACKGROUND
  Parvalbumin was identified as a major fish allergen, and has been well investigated. Collagen was identified as a second allergen; however, its allergenic properties remain uncharacterized. Although fish is an important staple in coastal countries, its thermostability is unknown. Therefore, we aimed to determine the thermostability of fish collagen as an allergen.
  
  
  METHODS
  Meat of seven bony and four cartilaginous fishes was heated at various temperatures and times, and extracts were analyzed using SDS-PAGE, IgE-ELISA, and SPTs.
  
  
  RESULTS
  Collagen was dissolved from heated meat of Pacific mackerel into a crude extract. Collagen in the extracts was degraded at a high heating load-140 °C (10 min) or 100 °C (320 min). However, ELISA revealed the IgE reactivities of patients' sera with the extracts were unchanged even after heating the samples. Patients strongly reacted to extract proteins of other bony fish, which were detected by patients' IgE even after heating at 100 °C (320 min). In contrast, reactivities of the extracts of cartilaginous fish were lower than those of bony fish. SPTs in one patient revealed that all bony and cartilaginous fish extracts prepared from heated meat elicited allergic reactions.
  
  
  CONCLUSIONS
  The IgE reactivity of patients' sera to fish collagen in extracts was retained even when fish meat was treated by a high heating load. As for the fish collagen, the IgE reactivities to cartilaginous fish were lower than that to bony fish. Reducing IgE reactivity to fish meat using heat is difficult, and other modalities will be required to produce hypoallergenic fish meat.
authors.affiliation: Department of Marine Biosciences, Tokyo University of Marine Science and Technology, Tokyo, Japan; Course of Safety Management in Food Supply Chain, Tokyo University of Marine Science and Technology, Tokyo, Japan. Electronic address: yukihiro@kaiyodai.ac.jp.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Kobayashi
authors.affiliation: Course of Safety Management in Food Supply Chain, Tokyo University of Marine Science and Technology, Tokyo, Japan.
authors.forename: Takuma
authors.initials: T
authors.lastname: Kuriyama
authors.affiliation: Department of Dermatology, Yokohama City University School of Medicine, Kanagawa, Japan.
authors.forename: Ryoko
authors.initials: R
authors.lastname: Nakagawara
authors.affiliation: Department of Dermatology, Yokohama City University School of Medicine, Kanagawa, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Aihara
authors.affiliation: Department of Marine Biosciences, Tokyo University of Marine Science and Technology, Tokyo, Japan; Course of Safety Management in Food Supply Chain, Tokyo University of Marine Science and Technology, Tokyo, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Hamada-Sato
mesh_terms: D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000276:immunology*; D000818:Animals; D002648:Child; D002675:Child, Preschool; D003094:Collagen / Q000737:chemistry / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005399:Fishes / Q000276:immunology*; D005512:Food Hypersensitivity / Q000175:diagnosis / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D007223:Infant; D008297:Male; D010320:Parvalbumins / Q000276:immunology; D055550:Protein Stability; D013696:Temperature; D055815:Young Adult
chemical_list: D000485:Allergens; D010320:Parvalbumins; D007073:Immunoglobulin E; D003094:Collagen
keywords: Bony fish; Cartilaginous fish; Collagen type I; Heating load; IgE