Figure 2

Differences in response to IL-12 or IL-18 between peripheral blood mononuclear cells (PBMCs) from healthy donors (H-PBMCs; n = 15) and from patients with RA (RA-PBMCs; n = 14). (a) H- or RA-PBMCs (1 × 10⁶/ml in RPMI 1640 medium with 10% fetal calf serum) were cultured in triplicate for 7 days with or without 1 ng/ml of IL-12, 5 ng/ml of IL-18, 2 μg/ml of IL-18 binding protein (IL-18BP), or their combination. (b) Cells were activated with 200 ng/ml of phytohemagglutinin (PHA) and 2 ng/ml of phorbol myristate acetate (PMA). IFN-γ concentrations in culture supernatants were measured by ELISA. Black bars represent RA-PBMCs and white bars represent H-PBMCs. *P < 0.05, **P < 0.01. NS, statistically not significant.