[Studies of D-penicillamine (4) : effects on antibody formation (author's transl)]

The value of D-penicillamine (D-PA) in the treatment of rheumatoid arthritis is now well established, however, the mode of action remains obscure. We studied the effects of D-PA on the primary and secondary homocytotropic antibody formation with various doses, timing, quantity of antigen stimuli and stress loading in mice. Homocytotropic antibody was assayed by rat PCA (IgE) or mouse PCA (IgG1), and the effects were compared with those of the other antirheumatic drugs such as aurothiomalate and chloroquine diphosphate and the immunosuppressive agents such as hydrocortisone and cyclophosphamide. The antibody formation was slightly suppressed by D-PA under various conditions induced by different quantities of antigen stimuli, while the effects of the other antirheumatic drugs and the immunosuppressive agents on the primary and secondary responses differed from that of D-PA. Stress loading applied with oral consecutive administration of saline for 3 weeks or by restraint with adhesive plaster from 3 days before the primary immunization reduced the antibody formation. D-PA restored the reduced IgE antibody formation after the secondary immunization and also weight of the spleen. These observations suggest that D-PA acts as an immunomodulating agent as the spleen weight and IgE antibody formation were recovered under conditions of induced stress.