title: An alternative inhibition method for determining cross-reactive allergens.
abstract: BACKGROUND
  Inhibition assays are an useful tool to identify the allergen of primary sensitization of cross-reactive allergens. Classical ELISA-based inhibition assays are limited by both the availability of commercial standardized allergen extracts and the experience and knowledge needed for making home-made extracts. Moreover the direct comparison of the inhibition ELISAs outcomes between different laboratories is difficult because of different sources of used allergen extracts and a number of methodological variations. Therefore, we propose a novel ImmunoCap (Phadia, Thermofisher Scientific) based immunoinhibition method with the use of commercially available Caps as the allergen source.
  
  
  METHODS
  The novel ImmunoCap based immunoinhibition method was developed and tested with sera from patients with a well-known cross-reactive sensitization for fig (Ficus carica) and ficus (Ficus benjamina). Results were compared with a classically applied inhibition method, i.e. addition of homemade allergen extract to patient serum.
  
  
  RESULTS
  The amount of allergens (fig and ficus extracts) needed to reach a similar degree of inhibition was comparable for both inhibition methods.
  
  
  CONCLUSIONS
  The ImmunoCap based inhibition assay, in addition to classical inhibition methods, is a valuable tool as the ImmunoCap analyzer and commercial allergens (Caps) are more widely available which makes the outcomes of inhibition tests comparable between different laboratories. Furthermore, in the ImmunoCap inhibition method the same protein source is used for both the inhibition of sIgE and sIgE measurement, which might be even more relevant when multiple cross-reactive allergens are tested.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Schmidt-Hieltjes
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Teodorowicz
authors.forename: Ad
authors.initials: A
authors.lastname: Jansen
authors.forename: Gerco
authors.initials: G
authors.lastname: den Hartog
authors.forename: Lisette
authors.initials: L
authors.lastname: Elfvering-Berendsen
authors.forename: Nicolette W
authors.initials: NW
authors.lastname: de Jong
authors.forename: Huub F J
authors.initials: HF
authors.lastname: Savelkoul
authors.forename: Janneke
authors.initials: J
authors.lastname: Ruinemans-Koerts
mesh_terms: D000485:Allergens / Q000097:blood* / Q000276:immunology* / Q000302:isolation & purification; D000937:Antigen-Antibody Reactions; D004796:Clinical Enzyme Tests; D003429:Cross Reactions / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D030681:Ficus / Q000276:immunology; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology
chemical_list: D000485:Allergens; D007073:Immunoglobulin E