title: Diamine oxidase levels in different chronic urticaria phenotypes.
abstract: BACKGROUND
  Diamine oxidase (DAO) is a polyamine-degrading enzyme also implicated in histamine metabolism. Chronic urticaria (CU) has a wide spectrum of clinical presentations and causes. Anisakis sensitisation associated chronic urticaria (CU+) has been characterised as a phenotype with different clinical and immunological characteristics and possibly associated with previous acute parasitism. We aimed to analyse serum DAO levels in different CU phenotypes. We further analysed the possible association of DAO with fish eating habits.
  
  
  METHODS
  We studied 35 CU+ patients and 39 non-sensitised CU patients (CU-) as well as 19 controls. We analysed fish-eating frequency as well as fish intake associated exacerbation of CU (FIAE) or gastro-intestinal complaints (GI). DAO levels were further analysed with respect to lymphoproliferative responses, cytokine and specific IgE production.
  
  
  RESULTS
  DAO levels were not different between CU and controls, but were significantly higher in CU+ than in CU-. CU+ patients with FIAE had lower DAO levels, but no differences were detected in patients with GI. DAO levels correlated positively with oily and canned fish consumption in CU-. In CU+, DAO levels correlated positively with specific Anisakis IgE, percentages of proliferation in Anisakis stimulated peripheral blood lymphocytes, serum IL-2 and IL-6, but correlated negatively with mitogen stimulated TGF-β in supernatants.
  
  
  CONCLUSIONS
  DAO levels in CU depend on fish-eating habits and in CU+ on the amount of specific IgE production. In the CU+ phenotype, lower levels of DAO predispose to urticaria exacerbation after fish intake, probably due to a relative insufficient enteric availability of this enzyme.
authors.affiliation: Servicio de Alergia, Instituto de Investigación Sanitaria-Hospital Universitario de la Princesa, Madrid, Spain. Electronic address: alvarodaschner@gmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Daschner
authors.affiliation: Departamento de Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: González-Fernández
authors.affiliation: Servicio de Alergia, Instituto de Investigación Sanitaria-Hospital Universitario de la Princesa, Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Valls
authors.affiliation: Servicio de Alergia, Instituto de Investigación Sanitaria-Hospital Universitario de la Princesa, Madrid, Spain.
authors.forename: C
authors.initials: C
authors.lastname: de Frutos
authors.affiliation: Departamento de Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Rodero
authors.affiliation: Departamento de Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Cuéllar
mesh_terms: D000328:Adult; D000485:Allergens / Q000276:immunology; D000818:Animals; D017129:Anisakiasis / Q000145:classification / Q000175:diagnosis*; D017163:Anisakis / Q000276:immunology*; D000947:Antigens, Helminth / Q000276:immunology; D049109:Cell Proliferation; D002908:Chronic Disease; D016207:Cytokines / Q000378:metabolism; D004032:Diet; D004435:Eating / Q000276:immunology*; D005260:Female; D005396:Fish Products; D005767:Gastrointestinal Diseases / Q000145:classification / Q000175:diagnosis*; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D014581:Urticaria / Q000145:classification / Q000175:diagnosis*
chemical_list: D000485:Allergens; D000947:Antigens, Helminth; D016207:Cytokines; D007073:Immunoglobulin E
keywords: Anisakis; Chronic urticaria; Cytokines; Diamine oxidase; Diet