Synovial Fluid and Serum Soluble Receptor Activator of Nuclear Factor kappa B Ligand (SRANKL) in Rheumatoid Arthritis and Osteoarthritis

1. To compare levels of synovial fluid soluble RANKL (sRANKL) between RA and Osteoarthritis (OA) patients.2. To compare serum levels of sRANKL between RA, OA patients and the control subjects.3. To find out if sRANKL is correlated with disease activity score (DAS), short erosion scale (SES) or with the treatment parameters in RA patients.