Action of antirheumatic drugs on the function of human leucocytes

The effect of 4 antirheumatic drugs, used in the basic therapy of patients with rheumatoid arthritis, on the cellular function of human leucocytes has been studied in vitro. Chloroquine and gold salt aurothioglucose inhibited in a dose-related manner the chemotaxis of polymorphonuclear neutrophils (PMN) and monocytes at therapeutic concentrations. D-Penicillamine only reduced migration of monocytes, but not that of PMN. Chloroquine has been found to suppress the phagocytosis and the microbicide effect of PMN, the transformation of T-lymphocytes and the chemotactic locomotion of the cells in similar concentrations. On the contrary, the concentrations of the gold salt and D-penicillamine inhibitory in these activities were substantially higher than those required for prevention of chemotaxis in vitro. Levamisole, known for immunostimulatory properties in patients, reduced the responsiveness of the leucocytes only at the highest dosage. The relevance of these experimental findings for the therapeutic approach and for their interaction with the host's defense mechanisms has been discussed.