The effect of some antirheumatic drugs in vivo on the response of spleen cells to concanavalin A in rats with chronic inflammation.

During the course of adjuvant arthritis in rats adherent spleen cells inhibited the response of spleen lymphocytes to the T-cell mitogen concanavalin A (Con A). The effects of 14 days treatment with various antirheumatic drugs on spleen cell responsiveness to Con A were investigated. Two nonsteroidal anti-inflammatory drugs, indomethacin (1 mg/kg/day p.o.) and acetylsalicylic acid (200 mg/kg/day p.o.) did not modify the spleen cell response, whereas treatment with chloroquine (50 mg/kg/day p.o.) or levamisole (5 mg/kg/day p.o.) further increased the inhibitory effects of the adherent suppressive spleen cells. On the contrary, treatment with sodium aurothiomalate (10 mg/kg/day i.m.), D-penicillamine (50 mg/kg/day p.o.) or pyritinol (50 mg/kg/day p.o.) significantly enhanced the response of the lymphocytes to Con A. In addition to the effects on spleen cell responsiveness, the ability of the various drug treatments to modify the polyarthritic lesions of the disease was investigated. It is suggested that this model may provide a valuable approach for evaluating the effects of antirheumatic drugs in vivo on immunological responsiveness during chronic inflammatory disease.