title: Cross-reactivity of pollen allergens: impact on allergen immunotherapy.
abstract: OBJECTIVE
  To provide guidelines for the rational formulation of allergen immunotherapy extracts based on knowledge of pollen allergen and epitope cross-reactivity.
  
  
  METHODS
  A PubMed search was performed for articles published from 1966 to 2007 using the keywords pollen, allergen, and cross-reactivity. Older literature was found through cross-referencing of older articles and older reviews on pollen cross-reactivity.
  
  
  METHODS
  Articles that dealt with crude pollen extracts and characterized allergens that addressed cross-reactivity were selected for inclusion in this review.
  
  
  RESULTS
  In addition to unique allergens, several families of botanic proteins have similarities that allow them to act as pan-allergens. Although frequently these are minor allergens, in some circumstances they may also be major allergens. Recent studies have investigated nonspecific lipid transfer proteins, calcium-binding proteins, pathogenesis-related protein families, and profilins. Calcium-binding proteins and nonspecific lipid transfer proteins are responsible for pollen-fruit interactions and pollen cross-reactivity. Clarification of pollen allergen enzymatic activity helps explain the ubiquitous nature of these proteins.
  
  
  CONCLUSIONS
  Characterization of specific pollen allergens and their protein families has provided insight into cross-reactivity. Clarification of these relationships allows for consolidation or substitution in formulation of inhalant extracts.
authors.affiliation: National Jewish Medical & Research Center, University of Colorado Health Sciences Center, Denver, Colorado, USA. weberr@njc.org
authors.forename: Richard W
authors.initials: RW
authors.lastname: Weber
mesh_terms: D052179:Antigens, Plant / Q000276:immunology* / Q000627:therapeutic use; D003429:Cross Reactions / Q000276:immunology*; D032462:Cycadopsida / Q000276:immunology; D003888:Desensitization, Immunologic; D000939:Epitopes / Q000276:immunology; D006801:Humans; D019684:Magnoliopsida / Q000276:immunology; D010940:Plant Proteins / Q000276:immunology / Q000627:therapeutic use; D011058:Pollen / Q000276:immunology*; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology / Q000628:therapy*
chemical_list: D052179:Antigens, Plant; D000939:Epitopes; D010940:Plant Proteins