title: IgE and non-IgE food allergy.
abstract: BACKGROUND
  Food allergy (FA) is characterized by an abnormal immunologic reactivity to food proteins. The gastro-intestinal tract serves not only a nutritive function but also is a major immunologic organ. Although previously thought to be triggered primarily by an IgE-mediated mechanism of injury, considerable evidence now suggests that non-IgE mechanisms may also be involved in the pathogenesis of FA.
  
  
  OBJECTIVE
  To review the immunologic disturbances that occur in FA and to correlate these with the clinical manifestations expressed in affected target organs based upon a classification of IgE and non-IgE mechanisms.
  
  
  METHODS
  Data collected from a computerized MEDLINE search were used for the analysis of the following topics: immediate GI hypersensitivity, oral allergy syndrome, acute urticaria and angioedema, acute bronchospasm, celiac disease, cow's milk enteropathy, dietary protein enterocolitis, breast milk colitis, proctolitis, proctitis, dermatitis herpetiformis, Heiner syndrome, eosinophilic gastroenteritis, atopic dermatitis, asthma, attention-deficit-hyperactivity disorder and behavioral disorders, as well as systems affected by mucosal associated lymphoid tissue-mediated injury of associated lymphoid tissues and the immunologic deviation to Th1 or Th2 mechanisms of FA.
  
  
  CONCLUSIONS
  The results of this review allow the construction of a central, unifying hypothesis for a new classification of FA as follows: the clinical manifestations of FA, expressed in affected target organs, may be the result of immunologic injury mediated by interaction of food antigens with contiguous elements of mucosal associated lymphoid tissue. These appear to be modulated by relative imbalances of the Th1/Th2 paradigm, which may be the ultimate determinant governing the expression of FA as IgE-mediated, non--IgE-mediated, or mixed forms of IgE/non-IgE mechanisms of FA.
authors.affiliation: Department of Pediatrics, Universidade do Grande Rio School of Medicine, Rio de Janeiro, Brazil.
authors.forename: Aderbal
authors.initials: A
authors.lastname: Sabra
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Bellanti
authors.forename: Jonathan Malka
authors.initials: JM
authors.lastname: Rais
authors.forename: Henry J
authors.initials: HJ
authors.lastname: Castro
authors.forename: Julia Mendez
authors.initials: JM
authors.lastname: de Inocencio
authors.forename: Selma
authors.initials: S
authors.lastname: Sabra
mesh_terms: D004044:Dietary Proteins / Q000009:adverse effects* / Q000276:immunology*; D005512:Food Hypersensitivity / Q000145:classification / Q000276:immunology*; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000145:classification / Q000209:etiology* / Q000276:immunology; D007107:Immune System / Q000276:immunology; D007108:Immune Tolerance / Q000276:immunology; D018928:Immunity, Mucosal / Q000276:immunology; D015994:Incidence
chemical_list: D004044:Dietary Proteins