Mycophenolate mofetil without antibody induction in cadaver vs. living donor pediatric renal transplantation

Mycophenolate mofetil (MMF) is a new immunosuppressive agent that blocks de novo purine synthesis in T and B lymphocytes via a potent selective inhibition of inosine monophosphate dehydrogenase. MMF has been shown to significantly reduce the incidence of acute rejection in both adult and pediatric renal transplantation. The impact of MMF on routine antibody induction therapy in pediatric renal transplantation has not been defined. Remarkably, a recent North American Pediatric Transplant Cooperative Study concluded that T-cell antibody induction therapy was deleterious for patients who received MMF. Our study examines the use of MMF in an evolving immunosuppressive strategy to avoid antibody induction in both living (LD) and cadaver (CAD) donor pediatric renal transplantation. We retrospectively analyzed the records of 43 pediatric renal transplants that received MMF-based triple therapy without antibody induction therapy between November 1996 and April 2000. We compared CAD (n = 17) with LD (n = 26). The two groups were similar demographically except that CAD had significantly younger donors than LD, 26.1 +/- 13.7 vs. 36.2 +/- 9.2 yr (p = 0.006). All the patients received MMF at 600 mg/m2/b.i.d. (maximum dose of 2 g/d) and prednisone with cyclosporine (86%) or tacrolimus (14%). Mean follow-up was >36 months for each group. Acute rejection rate at 6 months was 11.8% (CAD) vs. 15.4% (LD) (p = 0.999) and at 1 yr was 23.5% (CAD) vs. 26.9% (LD) (p = 0.999). Mean estimated glomerular filtration rate (ml/min/1.73 m2) at 6 months was 73.3 +/- 15.3 (CAD) vs. 87.6 +/- 24.2 (LD) (p = 0.068). Patient survival at 1, 2, and 3 yr was 100, 100, and 100% for CAD vs. 100, 96, and 96% for LD, respectively. Graft survival at 1, 2, and 3 yr was 100, 100, and 94% for CAD vs. 96, 88, and 71% for LD, respectively. Graft loss in CAD was because of chronic rejection (n = 2) while in LD it was because of non-compliance (n = 6), post-transplant lymphoproliferative disorder (n = 1), and sepsis (n = 1). In conclusion, MMF without antibody induction in both CAD and LD pediatric renal transplantation provides statistically similar and effective prophylaxis against acute rejection at 6 months and 1 yr post-transplant. The short-term patient and graft survival rates are excellent, however, non-compliance remains a serious challenge to long-term graft survival. Additional controlled studies are needed to define the role of MMF without antibody induction therapy in pediatric renal transplantation.