RF is mainly present in the serum of patients with rheumatoid arthritis but other diseases may also produce RF:Chronic inflammatory processes , infectious diseases & a variety of autoimmune diseases.The Rheumatoid Arthritis (RA) test on synovial fluid analyzes the fluid surrounding joints to detect signs of inflammation, autoimmune activity, and specific antibodies (e.g., rheumatoid factor, anti-CCP) that indicate RA. This test helps assess joint damage severity, differentiate RA from other joint disorders, and guide treatment strategies.