TNF and rheumatoid arthritis: These results are consistent with a study performed on circulating cytokine levels in patients with rheumatoid arthritis [30] who demonstrated that, if these cytokines are present in measurable amounts prior to treatment, successful treatment with the disease-modifying medication such as sulphasalazine will lead to a reduction in serum levels of IL-lα, IL-1β, and TNF-α.