Abstract
BACKGROUND: Although the discovery of new biomarkers in atopic dermatitis (AD) is challenging, it is valuable in diagnosis, assessment of severity, and evaluation of treatment response. OBJECTIVE: This study was designed to identify and validate new candidate protein biomarkers of AD via proteomic analysis. METHODS: Comparison of protein expression in the patients' serum before- and after-treatment and in patients without AD was performed via two-dimensional gel electrophoresis (2-DE), followed by image analysis. Spots showing differential expression in 2-DE image analysis were identified subsequently via nanoscale liquid chromatography-tandem mass spectrometry (LC-MS/MS) experiments. Blood tests were conducted to validate the results obtained by measuring the levels of candidate proteins. RESULTS: Based on LC-MS/MS analysis and database search, we identified ceruloplasmin (Cp) as a candidate protein. Serum Cp levels were significantly decreased in in pre-treated AD group than in control group. Additionally, the serum Cp level was higher in the mild group than in the moderate group of AD based on the Eczema Area and Severity Index (EASI) score. CONCLUSION: Low serum Cp levels are associated with AD, suggesting the potential role of Cp as a biomarker for diagnosis and severity assessment of AD.