Screening for specific biomarkers in serum of patients with rheumatoid arthritis using proteomic fingerprint techniques

AIM: To detect the serum protein biomarkers and establish a diagnostic model for rheumatoid arthritis (RA) adopting matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) combined with weak cationic exchange (WCX) magnetic beads, and to study the clinical significance of the model in early diagnosis of RA. METHODS: The serum samples from 60 patients with RA, 35 patients with osteoarthritis (OA) and 36 healthy controls were prepared with WCX magnetic beads, and then analyzed on PBSⅡ-C mass spectrometer reader. The protein spectra of the serum samples were normalized by Ciphergen ProteinChip software. The peak labeling was performed by Biomarker Wizard software. The specific protein biomarkers were screened by Biomarker Pattern software to construct a diagnostic model for RA. RESULTS: Totally 33 discriminative mass-to-charge (m/z) ratio were identified to be related with RA (P<0.05). Among these, the m/z peaks at 15 715.5D, 7 771.4D, 8 959.4D, 8 469.8D and 8 710.8D were used to construct a diagnostic model in a training set. In a test set, the sensitivity and specificity of the model were 86.7%and 90.0%, respectively. CONCLUSION: The potential protein biomarkers for RA are discovered in serum by MALDI-TOF-MS combined with WCX magnetic beads. The model of multiple biomarkers provides a powerful and reliable diagnostic method for RA diagnosis with high sensitivity and specificity.