title: Use of IgE and IgG4 epitope binding to predict the outcome of oral immunotherapy in cow's milk allergy.
abstract: BACKGROUND
  Oral immunotherapy (OIT) with cow's milk (CM) has been reported to induce a number of specific antibody responses, but these remain to be fully characterized. Our objective was to explore whether IgE and IgG4 epitope binding profiles could predict the risk of side effects during CM OIT.
  
  
  METHODS
  The study population consisted of 32 children (6-17 yr of age) with CM allergy: 26 children who successfully completed OIT and six children who discontinued therapy due to adverse reactions. We investigated sera drawn before and after OIT. We analyzed specific IgE and IgG4 binding to CM protein-derived peptides with a microarray-based immunoassay. Antibody binding affinity was analyzed with a competition assay where CM proteins in solution competed with peptides printed on the microarray.
  
  
  RESULTS
  IgE binding to CM peptides decreased and IgG4 binding increased following the OIT in children who attained desensitization. Compared with children who successfully completed OIT, those who discontinued OIT due to adverse reactions developed increased quantities and affinity of epitope-specific IgE antibodies and a broader diversity of IgE and IgG4 binding, but less overlap in IgE and IgG4 binding to CM peptides.
  
  
  CONCLUSIONS
  Detailed analysis of IgE and IgG4 binding to CM peptides may help in predicting whether CM OIT will be tolerated successfully. It may thus improve the safety of the therapy.
authors.affiliation: Children's Hospital, University of Helsinki, Helsinki, Finland.
authors.forename: Emma M
authors.initials: EM
authors.lastname: Savilahti
authors.forename: Mikael
authors.initials: M
authors.lastname: Kuitunen
authors.forename: Miko
authors.initials: M
authors.lastname: Valori
authors.forename: Ville
authors.initials: V
authors.lastname: Rantanen
authors.forename: Ludmilla
authors.initials: L
authors.lastname: Bardina
authors.forename: Gustavo
authors.initials: G
authors.lastname: Gimenez
authors.forename: Mika J
authors.initials: MJ
authors.lastname: Mäkelä
authors.forename: Sampsa
authors.initials: S
authors.lastname: Hautaniemi
authors.forename: Erkki
authors.initials: E
authors.lastname: Savilahti
authors.forename: Hugh A
authors.initials: HA
authors.lastname: Sampson
mesh_terms: D000293:Adolescent; D002648:Child; D003888:Desensitization, Immunologic; D000939:Epitopes / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology*; D016269:Milk Hypersensitivity / Q000628:therapy*; D016896:Treatment Outcome
chemical_list: D000939:Epitopes; D007074:Immunoglobulin G; D007073:Immunoglobulin E
keywords: IgE; IgG4; antibody affinity; cow's milk allergy; epitope; oral immunotherapy; peptide