Osteoprotegerin (OPG) levels, total soluble receptor activator of nuclear factor-Kappa B ligand (total sRANKL), and RANKL/OPG ratio in patients with rheumatoid arteritis

Rheumatoid arthritis (RA) is one of most important collagen vascular diseases. It has an unknown origin. The aim of this study was to evaluate circulating levels of osteoprotegerin (OPG), total soluble receptor activator of nuclear factor-Kappa B ligand (total sRANKL), and RANKL/OPG ratio in patients with RA. Forty-five females with RA, who fulfilled the American college of rheumatology (ACR) criteria for RA were included in this cross-sectional study. The overall disease activity was evaluated by the disease activity score based on 28 joint counts (DAS-28). The OPG and sRANKL were measured by the enzyme-linked immunosorbent assays (ELISA). The levels of C-reactive protein (CRP) were measured by ELISA.We used Pearson’s correlation for our comparisons. There was no statistically significant difference between the levels of CRP, OPG, sRANKL and RANKL/OPG ratio in terms of DAS-28 grades in our patients. No significant correlation was found between the serum levels of OPG and DAS-28 (P= 0.525), duration of the disease (P= 0.884), Z-score of the femur (P= 0.546) and Z-score of the spine (P= 0.492), T-score of the femur (P= 0.137) and T-score of the spine (P= 0.821) in the patient group. No significant correlations were found between sRANKL levels with DAS-28 (0.919), Z-score of the femur (P= 0.971), Z-score of the spine (P= 0.832) and T-score of the femur (P = 0170) in the studied groups. Our study showed that there was no significant correlation between CRP, OPG, sRANKL and RANKL/OPG ratio in DAS-28 grading of our patients. For this reason they will not be used for evaluating disease activity. However, there was a significant difference between case and control groups except for sRANKL (pg/mL).