Identification of Clinical Parameters Associated with Serum Oxidative Stress in Patients with Rheumatoid Arthritis

Objectives: Reactive oxygen species (ROS) are considered to be involved in the pathobiology of rheumatoid arthritis (RA); however, their association with disease activity has not been elucidated. In this study, we measured reactive oxygen metabolites (ROM) in patients with RA using a new Free Radical Analytical System and determined clinical parameters associated with ROM.

Methods: One hundred and fifty-two patients with RA and 80 patients with diabetes mellitus (DM) were included in this observational study. To measure ROM, the d-ROM test was performed on blood samples drawn from all subjects. The correlation between ROM and biomarkers, disease activity, doses of methotrexate (MTX), and prednisolone (PSL) were investigated.

Results: There were significant, positive correlations between ROM and CRP, matrix metalloproteinase 3 (MMP3), Disease Activity Score 28-erythrocyte sedimentation rate (DAS28-ESR), Clinical Disease Activity Index (CDAI), and the Simplified Disease Activity Index (SDAI). Multiple regression analysis revealed that CRP and DAS28-ESR were correlated with ROM.

Conclusions: The serum level of ROM was associated with CRP and DAS28-ESR, suggesting that ROM, in conjunction with CRP and MMP3, may be able to be used as a new biological disease marker to evaluate the disease activity of RA.