title: Atopic sensitization in the first year of life.
abstract: BACKGROUND
  There is conflicting evidence on whether allergen-specific memory is primed prenatally, whether this priming affects persistent immunologic effects, and whether it is modulated by the first environmental exposures in infancy.
  
  
  OBJECTIVE
  We sought to explore the course of atopic sensitization between birth and 12 months of age.
  
  
  METHODS
  Specific IgE levels for 6 food and 13 common inhalant allergens were assessed in cord blood and 1-year blood samples in the Protection against Allergy-Study in Rural Environments (PASTURE) birth cohort including 793 children from rural regions of 5 European countries. Detailed information on children's health, nutrition, and farm-related exposures was gathered by using a pregnancy questionnaire, 2 questionnaires at 2 and 12 months of age, and a diary covering the time in between.
  
  
  RESULTS
  Sensitization was more common at 12 months of age than at birth for almost all specificities. On an individual level, persistent sensitization to the same allergens was rare (1%), whereas transient (only at birth, 11%) and incident (only at 12 months, 34%) sensitization was seen in substantial proportions of children. Associations of transient sensitization with maternal sensitization differed with the allergen specificities, with the strongest associations for food allergens (odds ratio [OR], 10.6; 95% CI, 6.0-18.6) and the weakest associations for seasonal allergens (OR, 1.64; 95% CI, 0.94-2.86). Associations of maternal sensitization with incident sensitization were also seen. Incident sensitization was related to distinct prenatal and postnatal environmental exposures of mother and child, such as consumption of cereals for incident sensitization to seasonal allergens (OR, 0.66; 95% CI, 0.50-0.88).
  
  
  CONCLUSIONS
  IgE sensitization patterns change between birth and 12 months and are related to maternal and environmental influences.
authors: University Children's Hospital, Munich, Germany (Member of German Center for Lung Research). martin.depner@med.uni-muenchen.de
authors: Martin
authors: M
authors: Depner
authors: Markus J
authors: MJ
authors: Ege
authors: Jon
authors: J
authors: Genuneit
authors: Juha
authors: J
authors: Pekkanen
authors: Marjut
authors: M
authors: Roponen
authors: Maija-Riitta
authors: MR
authors: Hirvonen
authors: Jean-Charles
authors: JC
authors: Dalphin
authors: Vincent
authors: V
authors: Kaulek
authors: Susanne
authors: S
authors: Krauss-Etschmann
authors: Josef
authors: J
authors: Riedler
authors: Charlotte
authors: C
authors: Braun-Fahrländer
authors: Caroline
authors: C
authors: Roduit
authors: Roger
authors: R
authors: Lauener
authors: Petra I
authors: PI
authors: Pfefferle
authors: Juliane
authors: J
authors: Weber
authors: Erika
authors: E
authors: von Mutius
mesh_terms: D000485:Allergens / Q000276:immunology*; D004781:Environmental Exposure / Q000009:adverse effects; D005060:Europe; D005260:Female; D005312:Fetal Blood / Q000276:immunology; D006801:Humans; D006967:Hypersensitivity / Q000097:blood / Q000276:immunology*; D007073:Immunoglobulin E / Q000097:blood*; D007223:Infant; D008297:Male; D008431:Maternal-Fetal Exchange; D011247:Pregnancy; D012424:Rural Population; D011795:Surveys and Questionnaires
chemical_list: D000485:Allergens; D007073:Immunoglobulin E