Current treatments for RA include anti-tumor necrosis factor (TNF) alpha drugs, which have proven able to control disease progression and reduce the rate of disability.[8] However, a high percentage of patients do not respond sufficiently well to this type of treatment.[9] Given that therapy is expensive and can cause adverse events, factors that can predict an adequate response to treatment with anti-TNF alpha agents have been investigated.[10,11] Rheumatoid factor (RF) is an autoantibody that binds to the Fc portion of human IgG. This evidence concerns the gene TNF and rheumatoid arthritis.