Mycophenolate mofetil monotherapy:: An optimal, safe, and efficacious immunosuppressive maintenance regimen in kidney transplant patients

Long-term observation of stable renal allograft recipients converted to MMF monotherapy has confirmed our earlier experience that this MMF maintenance regimen is efficacious and safe after cadaveric kidney transplantation. During the first phase of the study, when CI doses were given concomitantly, MPA trough levels were maintained in the range of 2 to μ/mL, the same dose given in combination with CI and steroids to pediatric patients by Oellerich and associates. Once CIs had been withdrawn, MPA levels were maintained in the range of 2 to 4 μ/mL; it is important to remember that these levels were measured in the absence of CI, as concomitant administration of CsA and possibly tacrolimus can affect MPA concentrations. Mild conversion-induced rejection episodes occurred in 11% of patients, but at the time of this presentation, it did not appear that these rejection episodes had had any deleterious effects on long-term allograft survival. These results are in accordance with a recent meta-analysis of CI-sparing trials, which demonstrated no increase in graft failure. There was no evidence of late subclinical ongoing acute rejection events, as demonstrated by protocol biopsies taken under study conditions in half of the study group. Early improvements in allograft function have now been shown to extend beyond 2.35 years after conversion. These effects cannot be attributed simply to the acute removal of the vasoconstrictive effects of CI, as renal function continued to improve at 1-year and even 2-year follow-up. Although there is a trend toward a lower annual chronic graft loss rate (<3.5%) after MMF conversion, this is not statistically significant. Our patients had already been relesed from the adverse effects of steroids by our policy of early steroid withdrawal. This study shows that metabolic profiles can be further improved by withdrawal of CIs under MMF immunosuppression. Long-term amelioration of renal allograft recipients' atherogenic profiels may reduce the incidence of late cerebrovascular and cardiovascular accidents after transplantation and, thus, may contribute to an improved life expectancy and quality of life for selected groups of renal allograft recipients converted to MMF monotherapy.