title: Peanut sensitization pattern in Norwegian children and adults with specific IgE to peanut show age related differences.
abstract: BACKGROUND
  Peanuts contain potent food allergens and the prevalence of allergy is reported to increase, especially in children. Since peanut sensitization may differ between different geographical regions, we wanted to investigate the sensitization pattern to the individual peanut allergens in a Norwegian population.
  
  
  METHODS
  Cases reported to the Norwegian Food Allergy Register with sera positive to peanut extract were analyzed for specific IgE (sIgE) to the recombinant peanut allergens Ara h 1, Ara h 2, Ara h 3, Ara h 8 and Ara h 9 and to birch pollen extract. Serum samples negative to the above allergens were analyzed for sIgE to Ara h 6, and sIgE to Pru p 3 in peach were analyzed in sera positive to the cross-reactive allergen Ara h 9.
  
  
  RESULTS
  Highest frequency of sIgE to Ara h 2, often co-sensitized to Ara h 1 and 3, were found in the small children up to 6 years of age. From the age of 6 years, sensitization to Ara h 8 was predominant. The sIgE levels to the storage proteins Ara h 1, 2 and 3 were strongly correlated, as was the sIgE levels to Ara h 8 and birch pollen extract. A low sensitization rate of sIgE to Ara h 9 in young adults was observed, which sIgE levels were very strongly correlated to Pru p 3.
  
  
  CONCLUSIONS
  The sensitization to peanut allergens in a Norwegian population shows a clear age dependent pattern. The results add to the previously published research on the sensitization patterns of peanut sensitized patients in different geographical areas.
authors.affiliation: Division of Environmental Medicine, Department of Food, Water and Cosmetics, Norwegian Institute of Public Health, PO Box 4404, 0403 Oslo, Norway ; Lovisenberggata 8, Oslo, Norway.
authors.forename: Ellen
authors.initials: E
authors.lastname: Namork
authors.affiliation: Division of Environmental Medicine, Department of Food, Water and Cosmetics, Norwegian Institute of Public Health, PO Box 4404, 0403 Oslo, Norway.
authors.forename: Berit A
authors.initials: BA
authors.lastname: Stensby
keywords: Age related differences; Ara h 2; Ara h 8; Peanut allergens; Peanut sensitization pattern; sIgE