title: [Quality assurance in diagnostics: are there normal values for IgG-antibodies to cow's milk proteins?].
abstract: BACKGROUND
  The value of IgG-cow's milk antibodies is heavily disputed. Therefore, aim of the study was to establish normal values for these IgG-antibodies and to determine their diagnostic significance especially for gastrointestinal allergic manifestations.
  
  
  METHODS
  702 newborns were included prospectively. They received different feedings: mothers milk, cow's milk based formula and a partially or an extensively hydrolyzed formula. All children were examined annually or on occasion of allergic manifestations. An indirect immunofluorescent test was used for the assessment of IgG-antibodies against casein, beta-lactoglobulin, alpha-lactalbumin and bovine serum albumin. Values were expressed as geometric mean titers.
  
  
  RESULTS
  IgG-antibody titers rose slowly in the exclusively breast-fed children and peaked rapidly in the cow's milk formula-fed group, especially during the first year of life. There were no significant differences between children with and without allergic manifestations. Because of a large overlap between asymptomatic and symptomatic children it was impossible to establish normal values for the IgG-cow's milk antibodies.
  
  
  CONCLUSIONS
  The occurrence of IgG-cow's milk antibodies is a physiologic phenomenon without diagnostic significance. The costs of these determinations can be saved to improve process quality.
authors.affiliation: Zentrum für Kinderheilkunde, Universität Bonn.
authors.forename: K M
authors.initials: KM
authors.lastname: Keller
authors.forename: A
authors.initials: A
authors.lastname: Bürgin-Wolff
authors.forename: R
authors.initials: R
authors.lastname: Lippold
authors.forename: M J
authors.initials: MJ
authors.lastname: Lentze
mesh_terms: D000818:Animals; D015415:Biomarkers; D002417:Cattle; D002675:Child, Preschool; D005260:Female; D005526:Food, Formulated; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D007223:Infant; D007225:Infant Food; D007231:Infant, Newborn; D008297:Male; D008892:Milk / Q000276:immunology*; D016269:Milk Hypersensitivity / Q000097:blood / Q000175:diagnosis* / Q000276:immunology*; D008894:Milk Proteins / Q000276:immunology*; D008895:Milk, Human / Q000276:immunology; D011446:Prospective Studies; D012016:Reference Values
chemical_list: D015415:Biomarkers; D007074:Immunoglobulin G; D008894:Milk Proteins