title: Activated charcoal forms non-IgE binding complexes with peanut proteins.
abstract: BACKGROUND
  Conventional management of peanut-induced anaphylaxis is composed of administration of epinephrine, antihistamine, and steroid and stabilization of airway, ventilatory, and circulatory function. Therapies directed toward slowing or preventing further absorption of peanut protein from the gastrointestinal tract after accidental ingestion have not been a routine part of management.
  
  
  OBJECTIVE
  The purpose of this study was to determine the ability of activated charcoal to complex with peanut protein, thereby preventing its binding to either peanut-specific IgE or peanut-specific IgG.
  
  
  METHODS
  Peanut protein was coincubated with micronized activated charcoal suspension at pH 3.5 or 7.4. Peanut protein complexed with charcoal was removed by centrifugation. Binding of residual peanut protein to peanut-specific IgG was measured by a sandwich ELISA assay. Also, ability of uncomplexed peanut protein to bind to peanut-specific IgE was determined by Western blot and by skin prick testing in subjects with peanut allergy.
  
  
  RESULTS
  Activated charcoal (AC) formed complexes with peanut protein, effectively competing for binding with peanut-specific IgG in a sandwich ELISA assay. AC complexed efficiently with peanut protein at both neutral and acidic pH in as little as 60 seconds. AC was also able to remove IgE-binding peanut allergens from solution as determined by Western blot and by skin prick testing in subjects with peanut allergy. A ratio of 200 mg of AC to 1 mg peanut protein was required for complete removal of peanut protein from solution. AC was able to complex with peanut protein within food matrices such as ice cream and chocolate.
  
  
  CONCLUSIONS
  The data presented herein show that AC removes both IgE-binding and IgG-binding peanut proteins from solution rapidly at both neutral and acidic pH. These data suggest that administration of AC may be useful as an adjunct to slow or to prevent further absorption of peanut protein from the gastrointestinal tract after accidental ingestion by individuals with peanut allergy.
authors.affiliation: Department of Medicine, St Michael's Hospital, University of Toronto, Ontario, Cananda.
authors.forename: Peter
authors.initials: P
authors.lastname: Vadas
authors.forename: Boris
authors.initials: B
authors.lastname: Perelman
mesh_terms: D002606:Charcoal / Q000378:metabolism* / Q000627:therapeutic use; D004797:Enzyme-Linked Immunosorbent Assay; D037502:Galectin 3 / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007074:Immunoglobulin G / Q000378:metabolism*; D007408:Intestinal Absorption; D021183:Peanut Hypersensitivity / Q000188:drug therapy*; D010940:Plant Proteins / Q000378:metabolism*
chemical_list: D037502:Galectin 3; D007074:Immunoglobulin G; D010940:Plant Proteins; D002606:Charcoal