title: Early life IgE responses in children living in the tropics: a prospective analysis.
abstract: BACKGROUND
  There are few birth cohort studies analyzing IgE sensitization in the tropics.
  
  
  OBJECTIVE
  We aimed to describe the evolution of total IgE and specific IgE responses to house-dust mite (HDM) allergens and Ascaris in a birth cohort (Risk Factors for Asthma and Allergy in the Tropics, FRAAT), analyzing their relationships with wheezing.
  
  
  METHODS
  Total and specific IgE were measured by ImmunoCap in mothers and children at four different time points (S1-S4) between 0 and 42 months. Parasite infection was evaluated by stool examination.
  
  
  RESULTS
  Maternal total IgE (aOR: 2.43, 95% CI: 1.09-5.43; p = 0.03) and socio-demographic factors were associated with high cord blood (CB) total IgE. High CB total IgE was positively associated with higher Blomia tropicalis and Ascaris-specific IgE values during lifetime, but protected from recurrent wheezing (aOR: 0.26, 95% CI: 0.08-0.88, p = 0.03). Prevalence rates of IgE sensitization were high; at around 3 yr old, they were 33.3, 18.6, and 26.5% for B. tropicalis, Dermatophagoides pteronyssinus, and Ascaris, respectively. Indicators of unhygienic conditions were risk factors for HDM and Ascaris sensitization in children. A weak statistical association between B. tropicalis-specific IgE and ever wheezing was found (aOR: 1.47 95% CI: 1.00-2.28, p = 0.05).
  
  
  CONCLUSIONS
  In a socioeconomically deprived community from the tropics, sensitization to HDM allergens was very frequent at early life, especially to B. tropicalis. In contrast to expected according to the hygiene hypothesis, unhygienic/poverty conditions were risk factors for allergen sensitization. High CB total IgE levels were a risk factor for allergen sensitization but protected from recurrent wheezing.
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: Josefina
authors.initials: J
authors.lastname: Zakzuk
authors.forename: Nathalie
authors.initials: N
authors.lastname: Acevedo
authors.forename: Liliana
authors.initials: L
authors.lastname: Cifuentes
authors.forename: Adriana
authors.initials: A
authors.lastname: Bornacelly
authors.forename: Jorge
authors.initials: J
authors.lastname: Sánchez
authors.forename: Velky
authors.initials: V
authors.lastname: Ahumada
authors.forename: Johannes
authors.initials: J
authors.lastname: Ring
authors.forename: Markus
authors.initials: M
authors.lastname: Ollert
authors.forename: Luis
authors.initials: L
authors.lastname: Caraballo
mesh_terms: D000328:Adult; D000367:Age Factors; D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D039741:Antigens, Dermatophagoides / Q000276:immunology; D001196:Ascariasis / Q000453:epidemiology* / Q000276:immunology; D001200:Ascaris / Q000276:immunology*; D001249:Asthma / Q000453:epidemiology* / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003105:Colombia; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D008925:Mites / Q000276:immunology; D011446:Prospective Studies; D012135:Respiratory Sounds / Q000276:immunology; D012959:Socioeconomic Factors; D055815:Young Adult
chemical_list: D000909:Antibodies, Helminth; D039741:Antigens, Dermatophagoides; D007073:Immunoglobulin E
keywords: Blomia tropicalis; Dermatophagoides pteronyssinus; IgE; allergy; ascaris; sensitization; tropics; wheezing