title: Human Allergen-Specific IgG Subclass Antibodies Measured Using ImmunoCAP Technology.
abstract: BACKGROUND
  Knowledge of human IgG subclass antibody responses to various allergens has been hampered by a lack of reliable standardized assays. The aim here was to develop quantitative immunoassays for human IgG1, IgG2, and IgG3 antibodies using ImmunoCAP® technology and to evaluate their application.
  
  
  METHODS
  Enzyme conjugates with isotype-specific monoclonal antibodies and calibrators composed of purified myeloma paraproteins were developed for each assay and used together with other standardized assay reagents for the Phadia® 100 instrument. The calibrators were adjusted to the international reference preparation IRP 67/86. The assays were characterized and used together with other standard ImmunoCAP assays to measure antibodies to various allergens in preliminary studies.
  
  
  RESULTS
  The new assays had limits of quantitation of 1.0 (IgG1), 4.6 (IgG2), and 0.04 mgA/L (IgG3), and coefficients of variation of <20%. Only some minor cross-reactivity with IgG2 was observed for the specific IgG1 assay. The specific IgG2 assay showed a bias for the allotype G2m(23) and compensation factors were used to adjust the measured concentrations accordingly. Preliminary studies indicated a strong and stable IgG4 antibody response to β-lactoglobulin in healthy individuals, a high IgG1 and even higher IgG2 antibody response to house dust mite in sensitized and nonsensitized subjects, and a mixed IgG subclass response to venom allergens in allergic patients with increasing IgG4 antibody levels during venom immunotherapy.
  
  
  CONCLUSIONS
  The new research assays are valuable tools for immunological studies, enabling the characterization of antibody profiles using a standardized approach, and facilitating data interpretation and the comparison of results across studies.
authors.affiliation: Thermo Fisher Scientific, ImmunoDiagnostics, Uppsala University, Uppsala, Sweden.
authors.forename: Robert
authors.initials: R
authors.lastname: Movérare
authors.forename: Karin
authors.initials: K
authors.lastname: Blume
authors.forename: Peter
authors.initials: P
authors.lastname: Lind
authors.forename: René
authors.initials: R
authors.lastname: Crevel
authors.forename: Åsa
authors.initials: Å
authors.lastname: Marknell DeWitt
authors.forename: Stella
authors.initials: S
authors.lastname: Cochrane
mesh_terms: D000328:Adult; D000485:Allergens / Q000276:immunology*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity / Q000276:immunology*; D001514:Bee Venoms / Q000276:immunology; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007074:Immunoglobulin G / Q000032:analysis* / Q000145:classification / Q000276:immunology; D007129:Immunoglobulin Gm Allotypes / Q000276:immunology; D007132:Immunoglobulin Isotypes / Q000032:analysis* / Q000276:immunology; D007782:Lactoglobulins / Q000276:immunology; D039981:Pyroglyphidae / Q000276:immunology; D014862:Wasp Venoms / Q000276:immunology
chemical_list: D000485:Allergens; D000911:Antibodies, Monoclonal; D001514:Bee Venoms; D007074:Immunoglobulin G; D007129:Immunoglobulin Gm Allotypes; D007132:Immunoglobulin Isotypes; D007782:Lactoglobulins; D014862:Wasp Venoms