Objective: To discover the biomarkers of early rheumatoid arthritis (RA) patients and healthy person were analyzed by proteomic methods to discover serum biomarkers.
Methods: Samples of peripheral blood were collected form 10 newly diagnosed active RA patients, 5 males and 5 females, aged 54.3 +/- 12.78, with a disease course of 4.08 +/- 1.9 months, and 10 age and sex matched healthy persons. The samples were divided into 10 groups containing 1 sample of patient serum and 1 sample of healthy serum to undergo. High-molecular-weight protein (HMWP) was enriched by depletion of albumin with HiTrap Blue column and depletion of immunoglobulin G with HiTrap rProtein A column. Low-molecular-weight protein (LMWP) was enriched by C18 absorbent binding and elution. After comparative proteomic analysis, the different protein spots were identified using matrix-assisted laser desorption ionization-time of flight-ionization-mass spectrometry. (MALDI-TOF-MS).
Results: Marrow-related protein (MRP) 14, a protein of the S100 family was 100% positive in the RA patient sera and 100% negative in the sera of the healthy controls. MRP8, another protein of the S100 family, was 100% positive in the RA patient sera and 50% positive in the sera of the healthy controls. Ubiquitin was 90% positive in the RA patient sera and 10% positive in the sera of the healthy controls. The levels of apolipoprotein A-I (ApoA-I), serum amyloid A1 and A2 (SAA1/SAA2), and transthyretin of the RA patients were all significantly higher than those of the healthy controls.
Conclusion: MRP14/MRP8, SAA1/SAA2 and ubiquitin may play important roles in development of RA and their determination may benefit early diagnosis, evaluation of disease activity and investigation of new therapy targets.