EFFECTS OF LEFLUNOMIDE AND CYCLOSPORINE ON MYOCUTANEOUS ALLOGRAFT SURVIVAL IN THE RAT

The immunosuppressive effects of leflunomide and cyclosporine were eva luated in a rat neurovascularized myocutaneous allograft model. Inbred Brown-Norway and Lewis rats were served as donors and recipients, res pectively. All recipients were observed for 60 days or until allograft rejection occurred. All isograft controls (Lewis to Lewis, n=6) survi ved uneventfully. All control allografts (n=6) were rejected within 6 days. Allograft recipients (n=6) administered leflunomide (10 mg/kg/24 hr) rejected their allografts in 28.50+/-6.12 days, and allograft rec ipients (n=6), administered cyclosporine (5 mg/kg/24 hr) rejected thei r allografts in 24.33+/-10.48 days. When allograft recipients were adm inistered a combination of leflunomide and cyclosporine (10 mg/kg/24 h r and 5 mg/kg/24 hr, respectively), all allografts survived to 60 days with only partial rejection of the skin of one graft. The neuromuscul ar function of the allografts of the rats receiving combination therap y was comparable to that of the isografts. The combination of leflunom ide and cyclosporine controlled myocutaneous allorejection despite a s trong immunological challenge.