Cytokine network and polarization. (A) Circulating levels of tumour necrosis factor (TNF)-α and interferon (IFN)-γ were measured by enzyme-linked immunosorbent assay (ELISA) in serum from healthy control (HC) (n = 8), active rheumatoid arthritis (RA) (n = 10) and clinical remission (CR) (n = 20) patients. Levels were mostly below detection in HC (with the exception of two individuals). Increased levels of circulating cytokines were observed in active RA (P <0.05). In CR, a direct relationship was observed between interleukin (IL)-7 and IFN-γ (rho = 0.615, P = 0.005) but not with TNF-α. (B) Expression of TBET and GATA3 was measured by real-time PCR in cells from HC (n = 8), active RA (n = 10) in CR (n = 20). No significant changes were seen in TBET expression, however, GATA3 expression was lower in RA compared to HC (P = 0.0172) and CR (P = 0.0002). No difference was observed between HC and CR. In CR, a direct relationship was observed between serum IL-7 and TBET expression (rho = 0.600, P = 0.011) but not with GATA3.