EFFECTS OF LEFLUNOMIDE ON THE COURSE OF LISTERIOSIS IN MICE

The intensity of an infection with Listeria monocytogenes depends on t he immunological state of the body Impairment of the specific ol unspe cific defence can lead to severe and partly fatal complications such a s meningitis or septicaemia. In a normal defence situation affected in dividuals ale often not diagnozed because the infection appears as an unspecific indisposition. The new immunomodulator leflunomide ro-methy l-phenyl)-5-methyl-isoxazol-4-carboxamide, CAS 75706-12-6, HWA 486) ac ts mainly as immunosuppressive. Therefore, the influence of leflunomid e was investigated on the number of spleen bacteria in the first phase and on the lethality in both phases of mouse listeriosis. The infecte d mice were either in a normal defence state or in an immunocompromise d situation, which was produced by injection of cyclophosphamide or by dextran sulfate. A treatment with leflunomide, 20 mg/kg i.p., twice d aily over a period of 3 days caused no change of the lethality compare d with control mice. Likewise, combined administration of leflunomide mid ampicillin produced no alteration of the lethal outcomes in compar ison,vith the ampicillin medication alone the latter being highly effe ctive in any case. However; the number of spleen bacteria,vas signific antly higher in the group with combined treatment than in the ampicill in In summary, the treatment with leflunomide most likely will cause n o additional risk regarding an infection such as listeriosis, although in the case of an infection an increased care should be given to diag nostic and therapy.