Fig. 4.

T cell help essential for induction of IgM-RF production by PB B cells of healthy controls and patients with arthritis. PB B cells (10⁴/well) of healthy controls and patients with RA or other forms of arthritis (28: ankylosing spondylitis; 29: gout) were cultured on a layer of irradiated L-CD40L cells (5×10⁵/well; 70 Gy) in the presence of rhIL-2 (40 U/ml) and rhIL-10 (50 ng/ml). Duplicate culture supernatants were harvested after 14 days and analyzed. Data shown are the result of four independent experiments (< below detection limit of 6 mIU/ml).