Figure 4

Inhibition of T cell-induced TNF-α production by monocytes is specific for active RA. (a) Preactivated peripheral-blood T cells (10⁶/ml; see Materials and methods) were fixed and incubated for 24 hours with freshly isolated peripheral-blood monocytes (1.5 × 10⁶/ml) at a ratio of 7:1. The co-incubation assay was performed in the presence of 10% FCS, 10% serum from healthy donors (serum [control], n = 10), from patients with active RA (serum [aRA], n = 20) or from patients with non-active RA (serum [nRA], n = 20). All data are expressed as percentages of TNF-α produced in the co-culture system containing 10% FCS. Data are means ± SEM; levels of significance are as indicated. (b) Co-incubation assays (see (a)) were performed in the presence of 10% FCS, 10% serum from healthy donors (serum [control], n = 10)), serum from patients with psoriatic arthritis (serum [PsA], n = 9) or from patients with ankylosing spondylitis (serum [aSp], n = 9). All data are expressed as percentages of TNF-α produced in the co-culture system containing 10% FCS. Data are means ± SEM; levels of significance are as indicated.