title: Atopic predisposition of recipients in allergic transfusion reactions to apheresis platelets.
abstract: BACKGROUND
  The biologic mechanisms of allergic transfusion reactions (ATRs) are largely unknown. We sought to compare the atopic predisposition of platelet (PLT) recipients who experienced an ATR to nonreactive control recipients.
  
  
  METHODS
  We identified 37 consecutive apheresis PLT recipients who experienced an ATR and 26 matched controls. Total immunoglobulin (Ig)E and aero- and food allergen-specific IgE were quantified in plasma by a blood test for allergies (ImmunoCAP: Phadiatop and Fx5). IgE testing of apheresis PLT supernatants was also performed.
  
  
  RESULTS
  Pruritus and urticaria were manifest in 91.9 and 83.8% of all ATRs, with more severe respiratory symptoms and angioedema occurring in less than 15% of cases. No subject had anaphylaxis. Sex, age, and primary diagnosis were balanced between the two groups. Total and aeroallergen-specific IgE was higher among subjects experiencing an ATR in comparison to control subjects (median total IgE, 55.5 kU/L vs. 8.3 kU/L, p = 0.002; and median aeroallergen-specific IgE, 0.57 kUa/L vs. 0.36 kUa/L, p = 0.046). IgE antibody levels in apheresis products associated with ATRs were similar to control products (p > 0.1 for all IgE tests).
  
  
  CONCLUSIONS
  Recipient atopic predisposition, as defined by IgE sensitization, is a risk factor associated with ATRs.
authors.affiliation: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. wsavage1@jhmi.edu
authors.forename: William J
authors.initials: WJ
authors.lastname: Savage
authors.forename: Aaron A R
authors.initials: AA
authors.lastname: Tobian
authors.forename: Jessica H
authors.initials: JH
authors.lastname: Savage
authors.forename: Robert G
authors.initials: RG
authors.lastname: Hamilton
authors.forename: Paul M
authors.initials: PM
authors.lastname: Ness
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology*; D007073:Immunoglobulin E / Q000276:immunology; D008297:Male; D008875:Middle Aged; D017713:Platelet Transfusion / Q000009:adverse effects*; D010983:Plateletpheresis
chemical_list: D007073:Immunoglobulin E