title: Can immunoglobulin E-measurement replace challenge tests in allergic rhinoconjunctivits to grass pollen?
abstract: BACKGROUND
  There is minimal data available concerning the dose-response relationship between allergen exposure and clinical reactivity for outdoor aeroallergens, such as timothy grass pollen. Timothy pollen-specific IgE (sIgE) determinations might assist in predicting the clinical reactivity in patients with allergic rhinoconjunctivitis (ARC).
  
  
  METHODS
  Allergen-sIgE antibody levels of timothy grass pollen were correlated with individual threshold doses eliciting allergic reactions in skin prick test (SPT), conjunctival (CPT) and nasal (NPT) provocation tests in patients suffering from pollen-induced rhinoconjunctivitis and healthy controls.
  
  
  RESULTS
  One hundred and four patients with ARC (median age: 27 years; range: 18-64; females: 58%) and 36 controls (25 years (22-77); females: 70%) were included in the study. Ninety-six percent of the patients showed a positive reaction in the nasal and 57% showed a positive reaction in the conjunctival provocation. With regarding to titrated SPT, 98% of the patients showed a positive skin test reaction; correlating with the level of sIgE for timothy (P < 0.001). For both provocation protocols, there was no correlation between the provocation concentration at the reaction and the level of sIgE for timothy. The ratio of sIgE/total IgE correlated with the dilution level of SPT (P < 0.002) and CPT (P < 0.01), respectively.
  
  
  CONCLUSIONS
  A dose-response relationship between the levels of sIgE and clinical outcome of timothy allergen exposure could not be established. Although IgE-determination remains an important key element in allergy diagnosis, provocation tests are procedures of choice if the clinical relevance of an allergen has to be confirmed.
authors.affiliation: ZAUM-Center for Allergy and Environment, Division of Environmental Dermatology and Allergy, Helmholtz Center Munich, Technische Universität München, Munich, Germany. huss-marp@lrz.tum.de
authors.forename: J
authors.initials: J
authors.lastname: Huss-Marp
authors.forename: U
authors.initials: U
authors.lastname: Darsow
authors.forename: K
authors.initials: K
authors.lastname: Brockow
authors.forename: F
authors.initials: F
authors.lastname: Pfab
authors.forename: I
authors.initials: I
authors.lastname: Weichenmeier
authors.forename: W
authors.initials: W
authors.lastname: Schober
authors.forename: C J
authors.initials: CJ
authors.lastname: Petersson
authors.forename: M P
authors.initials: MP
authors.lastname: Borres
authors.forename: J
authors.initials: J
authors.lastname: Ring
authors.forename: H
authors.initials: H
authors.lastname: Behrendt
mesh_terms: D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000009:adverse effects / Q000276:immunology*; D000937:Antigen-Antibody Reactions; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000032:analysis* / Q000276:immunology; D007159:Immunologic Tests / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009299:Nasal Provocation Tests; D031784:Phleum / Q000276:immunology*; D011058:Pollen / Q000009:adverse effects / Q000276:immunology*; D011446:Prospective Studies; D006255:Rhinitis, Allergic, Seasonal / Q000175:diagnosis* / Q000276:immunology*; D012882:Skin Tests; D055815:Young Adult
chemical_list: D000485:Allergens; D007073:Immunoglobulin E