title: Serum lactoferrin level as a serologic biomarker for allergic rhinitis.
abstract: BACKGROUND
  Allergic rhinitis (AR) is a very common disease and a risk factor for allergic asthma. The discovery of new biomarkers for the early detection of AR would improve the clinical outcomes and reduce socio-economic burden. We sought to identify a novel serologic marker for detection of AR using a proteomic approach.
  
  
  METHODS
  To identify the proteins involved in AR, comparative proteomics was applied using nasal lavage fluids (NLFs) taken before and after a nasal provocation test (NPT) with Dermatophagoides pteronyssinus (Dpt) in a subject with AR sensitized to Dpt. The clinical relevance of the identified proteins was evaluated by ELISA using NLFs and sera from the three study groups: Dpt-sensitive AR; asymptomatic Dpt-sensitive controls; and non-atopic healthy controls. The sensitivities and specificities of the candidate proteins for predicting AR were determined using receiver operating characteristic (ROC) curves.
  
  
  RESULTS
  In proteomic analysis, lactoferrin expression was up-regulated after NPT. The validation study using ELISA showed a significantly lower serum lactoferrin level in the AR group than those of the other two groups (P<0.05, respectively). To discriminate between subjects with or without AR, the optimal serum cut-off level of lactoferrin was set at <307 ng/mL using the ROC curve. The sensitivity and specificity for predicting AR were 81.4% and 58%. When combined with serum Dpt-specific IgE level, the sensitivity and specificity for predicting AR were 76.7% and 79.2%.
  
  
  CONCLUSIONS
  These results suggest that the serum lactoferrin level is associated with the phenotype of Dpt-sensitive AR, and in combination with the serum Dpt-specific IgE level, may be a potential serologic marker for early detection of AR.
authors.affiliation: Department of Allergy and Rheumatology, Kyung Hee University College of Medicine, Seoul, Korea.
authors.forename: G-S
authors.initials: GS
authors.lastname: Choi
authors.forename: S-Y
authors.initials: SY
authors.lastname: Shin
authors.forename: J-H
authors.initials: JH
authors.lastname: Kim
authors.forename: H-Y
authors.initials: HY
authors.lastname: Lee
authors.forename: N S
authors.initials: NS
authors.lastname: Palikhe
authors.forename: Y-M
authors.initials: YM
authors.lastname: Ye
authors.forename: S-H
authors.initials: SH
authors.lastname: Kim
authors.forename: H-S
authors.initials: HS
authors.lastname: Park
mesh_terms: D000328:Adult; D000818:Animals; D015415:Biomarkers / Q000097:blood; D040002:Dermatophagoides pteronyssinus / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D007781:Lactoferrin / Q000097:blood* / Q000276:immunology; D008297:Male; D010641:Phenotype; D012221:Rhinitis, Allergic, Perennial / Q000097:blood* / Q000175:diagnosis / Q000276:immunology; D012680:Sensitivity and Specificity; D012882:Skin Tests
chemical_list: D015415:Biomarkers; D007073:Immunoglobulin E; D007781:Lactoferrin