Evaluation of Biochemical and Oxidative Stress Markers in the Early Stages of Rheumatoid Arthritis in a Comparative Study of Two Different Therapeutic Approaches

Rheumatoid arthritis (RA) is a well-known autoimmune inflammatory disease that affects the diarthrodial joints. Inflammation increases the production of reactive oxygen species (ROS), which may explain why RA is one of the diseases that induce oxidative stress. This study aimed to evaluate potential differences in biochemical, hematological and oxidative stress markers in early stages of RA and after different treatment regimens. The study involved 111 patients, 28 men and 83 women, aged 34 to 59 years who were divided based on their c-reactive protein (CRP) levels into inactive RA patients (IRA) with CRP < 1.3 (n = 57, 22 men and 35 women) and active RA patients (ARA) with CRP ≥ 1.3 (n = 54, 6 men and 48 women). The study participants were divided into two groups, A and B, based on their treatment regimen. Group A, which comprised 90% IRA, received methotrexate (MTX) monotherapy. Group B, which comprised 90% ARA, received a combination of leflunomide, a conventional disease-modifying antirheumatic drug (DMARD), and a biologic DMARD. Hematological, biochemical, oxidative stress and RA-specific biomarkers were measured twice in groups A and B, in the early stage in the disease, before and 3 months post-treatment, using conventional colorimetric, fluorometric and immunological assays. According to the results of our study, glutathione peroxidase (GPx), ROS, calcium (Ca) and phosphorus (P) ions, vitamin C and D, and lipid profile could serve as potential diagnostic markers in the early stages of the disease. Both treatment options were equally effective in improving the overall health of the patients. However, treatment resulted in a further increase in ROS levels and a decrease in antioxidant markers.