Fig. 5.
Interleukin (IL)-6 but not tumour necrosis factor (TNF)-α expression by monocytes increases over 12 months in early inflammatory arthritis (EIA). Peripheral blood mononuclear cells (PBMC) were isolated by density gradient separation and plated at a density of 1 × 106 with either phorbol myristate acetate (PMA)/ionomycin for 3 h (a,b) or lipopolysaccharide (LPS) for 4 h (c,d) prior to staining for CD3, CD4, IL-17 and interferon (IFN)-γ, or CD14, TNF-α and IL-6, respectively. Sixteen patients had complete data available for visits at baseline, 6 and 12 months. Symbols and lines represent individual patients. Patients classified as rheumatoid arthritis (RA) are shown by open symbols, and undifferentiated arthritis (UA) by closed symbols. Changes over time were analysed using repeated-measures analysis of variance (anova) or Friedman test with Dunn's multiple comparison post-test versus baseline. ***P < 0·001.