title: IgE responses to Ascaris and mite tropomyosins are risk factors for asthma.
abstract: BACKGROUND
  The relationship between helminthiases and allergy is a matter of considerable interest and research. In the tropics, house dust mite exposure, a known risk factor for asthma, is frequently concurrent with helminth infections. It remains to be defined whether infection with the common roundworm Ascaris or its bystander immunological effects influence the prevalence and pathogenesis of asthma independently of mite sensitization.
  
  
  OBJECTIVE
  To investigate the relationship between the IgE responses to Ascaris and its purified allergens and the risk of asthma in a tropical country.
  
  
  METHODS
  A nested case-control study was performed in 356 subjects who reported current and past asthma symptoms (asthmatics) and 435 controls that had never experienced such symptoms. They were tested for serum levels of total IgE and specific IgE to Ascaris extract, Asc s 1 (ABA-1), Asc l 3 (tropomyosin) and GST (glutathione transferase). In addition, specific IgE to Dermatophagoides pteronyssinus, Blomia tropicalis and their tropomyosins Der p 10 and Blo t 10 was measured. Sensitization was defined as a positive specific IgE result to any extract or recombinant allergen.
  
  
  RESULTS
  Sensitization to Ascaris and D. pteronyssinus was independently associated with asthma after adjustment for age, gender, socio-economic stratum, city and other IgE levels (adjusted ORs: 2.17; 95% CI 1.37-3.42 and 2.46; 95% CI 1.54-3.92), respectively. There was also a significant association with sensitization to the highly allergenic and cross-reactive tropomyosins Asc l 3, Blo t 10 and Der p10 (aORs: 1.76; 95% CI 1.21-2.57, 1.64; 95% CI 1.14-2.35 and 1.51; 95% CI 1.02-2.24), respectively.
  
  
  CONCLUSIONS
  IgE responses to Ascaris are associated with asthma symptoms in a population living in the tropics. Sensitization to the cross-reactive Ascaris and mite tropomyosins partially underlies this finding. These results have potential relevance in asthma diagnosis and management.
authors.affiliation: Institute for Immunological Research, University of Cartagena, Cartagena, Colombia.
authors.forename: V
authors.initials: V
authors.lastname: Ahumada
authors.affiliation: Division of Pediatric Allergy and Otorhinolaryngology, Fundación Santafé de Bogotá, Bogotá, Colombia.
authors.forename: E
authors.initials: E
authors.lastname: García
authors.affiliation: Research Department, Fundación Cardioinfantil - Instituto de Cardiología, Bogotá, Colombia.|Department of Clinical Epidemiology and Biostatistics, School of Medicine, Pontificia Universidad Javeriana, Bogotá, Colombia.
authors.forename: R
authors.initials: R
authors.lastname: Dennis
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, School of Medicine, Pontificia Universidad Javeriana, Bogotá, Colombia.
authors.forename: M X
authors.initials: MX
authors.lastname: Rojas
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, School of Medicine, Pontificia Universidad Javeriana, Bogotá, Colombia.
authors.forename: M A
authors.initials: MA
authors.lastname: Rondón
authors.affiliation: Division of Biostatistics, School of Public Health, University of Texas Health Science Center at Houston, Houston, TX, USA.|Michael & Susan Dell Center for Healthy Living, Austin, TX, USA.
authors.forename: A
authors.initials: A
authors.lastname: Pérez
authors.affiliation: Division of Pediatric Allergy and Otorhinolaryngology, Fundación Santafé de Bogotá, Bogotá, Colombia.
authors.forename: A
authors.initials: A
authors.lastname: Peñaranda
authors.affiliation: Research Department, Fundación Cardioinfantil - Instituto de Cardiología, Bogotá, Colombia.|Health Sciences Research Center (CICS), Universidad del Rosario, Bogotá, Colombia.
authors.forename: A M
authors.initials: AM
authors.lastname: Barragán
authors.affiliation: Institute for Immunological Research, University of Cartagena, Cartagena, Colombia.|Foundation for the Development of Medical and Biological Sciences (Fundemeb), Cartagena, Colombia.
authors.forename: S
authors.initials: S
authors.lastname: Jimenez
authors.affiliation: Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK.|Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow, UK.
authors.forename: M W
authors.initials: MW
authors.lastname: Kennedy
authors.affiliation: Institute for Immunological Research, University of Cartagena, Cartagena, Colombia.|Foundation for the Development of Medical and Biological Sciences (Fundemeb), Cartagena, Colombia.
authors.forename: L
authors.initials: L
authors.lastname: Caraballo
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000485:Allergens / Q000276:immunology; D000818:Animals; D000918:Antibody Specificity / Q000276:immunology; D001200:Ascaris / Q000276:immunology*; D001249:Asthma / Q000453:epidemiology / Q000276:immunology*; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D008925:Mites / Q000276:immunology*; D016017:Odds Ratio; D012307:Risk Factors; D012737:Sex Factors; D014335:Tropomyosin / Q000276:immunology*; D055815:Young Adult
chemical_list: D000485:Allergens; D014335:Tropomyosin; D007073:Immunoglobulin E
keywords: Ascaris; IgE; allergen; ascariasis; asthma; mite; recombinant allergens; tropomyosin