The peripheral blood mononuclear cells (PBMC) from healthy volunteers and patients with rheumatoid arthritis (RA) at different stages were examined for their proliferation and growth factor production in response to 12-O-tetradecanoyl phorbol-13-acetate (TPA) .
The mitogenic response and the factor production supporting the growth of pokeweed mitogen (PWM) -stimulated lymphoblasts, which were induced independently upon IL-2 production, were significantly higher in RA-PBMC than those in PBMC from healthy volunteers. A RA drug, salazosulfapyridine (SASP) was examined for its suppressive effect on these IL-2-independent proliferation induced by TPA. The results showed that SASP at concentrations greater than 20-50μg/ml significantly suppressed the mitogenic response of PBMC to TPA. The drug also showed a suppressive effect on another IL-2-independent proliferation of PBMC induced by heat-killed Streptococcus pyogenes (OK-432), which was also a phenomenon mediated independently of IL-2 production.
The significance of this suppressive effect of SASP was proposed as an experimental model for studying the therapeutic effect of SASP on RA diseases.
