TNF and rheumatoid arthritis: Previous studies also showed a positive correlation between plasma levels of TNF-α and activity of the disease in the newly diagnosed RA patients and not in patients who were on DMARD treatment [7,19]. Shrivastava et al. and others reported that DAS28 scores showed a significant correlation with serum TNF-α in the high disease activity subgroup of RA patients [7,23,24].