TNF and rheumatoid arthritis: In addition, plasma concentrations of VEGF (56 ± 123 vs 594 ± 810 pg/ml), TNF-α (13.71 ± 29.15 vs 5.46 ± 2.41 pg/ml) and IL-6 (14.49 ± 23.42 vs 0.9 ± 0.74 pg/ml) were significantly higher in RA patients than in healthy controls.