Serum lactoferrin level as a serologic biomarker for allergic rhinitis.
Choi GS, Shin SY, Kim JH, Lee HY, Palikhe NS, Ye YM, Kim SH, Park HS.
SourceDepartment of Allergy and Rheumatology, Kyung Hee University College of Medicine, Seoul, Korea.

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%.

CONCLUSION: 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.
Clin Exp Allergy 2010;Mar;40(3):403-10