title: Altered allergen binding capacities of Amb a 1-specific IgE and IgG4 from ragweed-sensitive patients receiving immunotherapy.
abstract: BACKGROUND
  The mechanisms for the effectiveness of allergen immunotherapy (IT) are not well understood. The binding potential for immunoglobulins is a function of both antibody concentration and affinity (K(A)).
  
  
  OBJECTIVE
  The purpose was to perform a cross-sectional preliminary study to investigate any differences in allergen-specific antibody affinity and concentration following ragweed immunotherapy by introducing a new concept of antibody binding capacity ([Ig] X K(A)).
  
  
  METHODS
  The binding capacity of allergen-specific IgE and IgG4 was determined for ragweed-allergic individuals undergoing ragweed immunotherapy and compared with the capacity of ragweed-specific IgE and IgG4 for allergic individuals not receiving immunotherapy.
  
  
  RESULTS
  The mean binding capacity for IgG4 after long-term immunotherapy was 1.6 log units higher (P < .0001) than for individuals not receiving IT. The binding capacity for allergen-specific IgE was 1.2 log units lower following long-term immunotherapy (P < .0001) compared with individuals not receiving ragweed IT.
  
  
  CONCLUSIONS
  We hypothesize that a primary effect of immunotherapy is to increase IgG4 binding capacity and concomitantly decrease IgE binding capacity.
authors.affiliation: Asthma and Allergy Center, Department of Medicine, University of Minnesota Medical School, Minneapolis 55455, USA. piers016@gold.tc.umn.edu
authors.forename: L K
authors.initials: LK
authors.lastname: Pierson-Mullany
authors.forename: D
authors.initials: D
authors.lastname: Jackola
authors.forename: M
authors.initials: M
authors.lastname: Blumenthal
authors.forename: A
authors.initials: A
authors.lastname: Rosenberg
mesh_terms: D000328:Adult; D000485:Allergens / Q000378:metabolism; D000915:Antibody Affinity / Q000502:physiology; D000918:Antibody Specificity; D052179:Antigens, Plant; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology*; D007167:Immunotherapy; D008297:Male; D010940:Plant Proteins / Q000276:immunology*; D011058:Pollen
chemical_list: D000485:Allergens; C026967:Amb a I protein, Ambrosia artemisiifolia; D052179:Antigens, Plant; D007074:Immunoglobulin G; D010940:Plant Proteins; D007073:Immunoglobulin E