Delayed hypersensitivity to tuberculin in rats: effects of antirheumatic drugs.

The effects of different antirheumatic drugs administered according to various dosing regimes on tuberculin hypersensitivity in rats have been assessed quantitating the changes of exudate volume and mononuclear cells immigration at the site of challenge. Dosing at the time of sensitization with aurothiomalate and D-penicillamine enhanced the cell immigration which was decreased by similar treatment with levamisole. Cyclophosphamide increased the exudate formation. Indomethacin had no effect. Dosing at the time of challenge caused a marked reduction of both the parameters by aurothiomalate and cyclophosphamide and enhancement by levamisole. D-penicillamine increased only the cellular immigration and indomethacin the exudate formation. Long treatment with aurothiomalate and cyclophosphamide suppressed the responses. Similar treatment with D-penicillamine and levamisole produced a significant enhancement. Indomethacin had no effect. The relevance of these findings to the testing and mode of action of antirheumatic drugs is discussed.