title: Threshold Dose Distribution in Walnut Allergy.
abstract: BACKGROUND
  In food allergy, eliciting doses (EDs) of foods on a population level can improve risk management and labeling strategies for the food industry and regulatory authorities. Previously, data available for walnut were unsuitable to determine EDs.
  
  
  OBJECTIVE
  The objective of this study was to determine EDs for walnut allergic adults and to compare with previously established threshold data for peanut and tree nuts.
  
  
  METHODS
  Prospectively, adult subjects with a suspected walnut allergy underwent a low-dose double-blind, placebo-controlled food challenge. Individual no observed and lowest observed adverse effect levels were determined and log-normal, log-logistic, and Weibull models were fit to the data. Estimated ED values were calculated for the ED5,ED10, and ED50, the dose respectively predicted to provoke an allergic reaction in 5%, 10%, and 50% of the walnut allergic population.
  
  
  RESULTS
  Fifty-seven subjects were challenged and 33 subjects were confirmed to be walnut allergic. Objective symptoms occurred in 20 of the positive challenges (61%). The cumulative EDs in the distribution models ranged from 3.1 to 4.1 mg for the ED05, from 10.6 to 14.6 mg walnut protein for the ED10, and from 590 to 625 mg of walnut protein for the ED50.
  
  
  CONCLUSIONS
  Our data indicate that population EDs for walnut are slightly higher compared with those for peanut and hazelnut allergy. Currently available data indicate that the ED values for hazelnut could be used as a conservative temporary placeholder when implementing risk management strategies for other tree nuts where little or no food challenge data are available.
authors.affiliation: Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht, The Netherlands. Electronic address: m.a.blankestijn@umcutrecht.nl.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Blankestijn
authors.affiliation: The Netherlands Organization for Applied Scientific Research (TNO), Zeist, The Netherlands.
authors.forename: Ben C
authors.initials: BC
authors.lastname: Remington
authors.affiliation: Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht, The Netherlands; The Netherlands Organization for Applied Scientific Research (TNO), Zeist, The Netherlands.
authors.forename: Geert F
authors.initials: GF
authors.lastname: Houben
authors.affiliation: Food Allergy Research & Resource Program (FARRP), University of Nebraska, Lincoln, Neb.
authors.forename: Joe L
authors.initials: JL
authors.lastname: Baumert
authors.affiliation: Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: André C
authors.initials: AC
authors.lastname: Knulst
authors.affiliation: The Netherlands Organization for Applied Scientific Research (TNO), Zeist, The Netherlands.
authors.forename: W Marty
authors.initials: WM
authors.lastname: Blom
authors.affiliation: Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Rob J B
authors.initials: RJB
authors.lastname: Klemans
authors.affiliation: Food Allergy Research & Resource Program (FARRP), University of Nebraska, Lincoln, Neb.
authors.forename: Steve L
authors.initials: SL
authors.lastname: Taylor
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000485:Allergens / Q000276:immunology*; D005260:Female; D005515:Food Labeling; D006801:Humans; D007114:Immunization; D031324:Juglans / Q000276:immunology*; D008297:Male; D021184:Nut Hypersensitivity / Q000175:diagnosis* / Q000178:diet therapy*; D011446:Prospective Studies; D012306:Risk
chemical_list: D000485:Allergens
keywords: Allergen thresholds; Eliciting doses; Food allergy; Threshold dose distributions; Walnut