Analysis of serum biomarkers in human knee osteoarthritis

AIM: To analyze the proteomic components of the sera from knee osteoarthritis patients and normal people, and to search proteins that might serve as serum biomarkers for osteoarthritis diagnosis, treatment or pathogenesis. METHODS: Two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) was applied to analyze the sera obtained from the patients with knee osteoarthritis (n=4) and normal controls (n=4). The differentially expressed proteins were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Western blotting analysis was applied to confirm the results. RESULTS: Comparative proteomic data of serum from the patients with osteoarthritis was successfully obtained. Eight differentially expressed protein spots were observed. Five up-regulated and 3 down-regulated proteins were identified. Western blot analysis confirmed that α₂-macroglobulin was increased. CONCLUSION: There are significant differences between serum proteins obtained from the patients with knee osteoarthritis and normal controls. α₂-Macroglobulin might be utilized as potential biomarkers for the diagnosis and treatment of osteoarthritis.