Pediatric renal transplantation under tacrolimus-based immunosuppression

Background. Tacrolimus has been used as a primary immunosuppressive agent i n adult and pediatric renal transplant recipients, with reasonable outcomes . Methods. Between December 14, 1989 and December 31, 1996, 82 pediatric rena l transplantations alone were performed under tacrolimus-based immunosuppre ssion without induction anti-lymphocyte antibody therapy. Patients undergoi ng concomitant or prior liver and/or intestinal transplantation were not in cluded in the analysis. The mean recipient age was 10.6+/-5.2 years (range: 0.7-17.9). Eighteen (22%) cases were repeat transplantations, and 6 (7%) w ere in patients with panel-reactive antibody levels over 40%. Thirty-four ( 41%) cases were with living donors, and 48 (59%) were with cadaveric donors . The mean donor age was 27.3+/-14.6 years (range: 0.7-50), and the mean co ld ischemia time in the cadaveric cases was 26.5+/-8.8 hr. The mean number of HLA matches and mismatches was 2.8+/-1.2 and 2.9+/-1.3; there were five (6%) O-Ag mismatches. The mean follow-up was 4.0+/-0.2 years. Results. The 1- and 4-year actuarial patient survival was 99% and 94%. The 1- and 4-year actuarial graft survival was 98% and 84%. The mean serum crea tinine was 1.1+/-0.5 mg/dl, and the corresponding calculated creatinine cle arance was 88+/-25 ml/min/1.73 m(2). A total of 66% of successfully transpl anted patients were withdrawn from prednisone. In children who were withdra wn from steroids, the mean standard deviation height scores (Z-score) at th e time of transplantation and at 1 and 4 years were -2.3+/-2.0, -1.7+/-1.0, and +0.36+/-1.5. Eighty-six percent of successfully transplanted patients were not taking anti-hypertensive medications. The incidence of acute rejec tion was 44%; between December 1989 and December 1993, it was 63%, and betw een January 1994 and December 1996, it was 23% (P=0.0003). The incidence of steroid-resistant rejection was 5%. The incidence of delayed graft functio n was 5%, and 2% of patients required dialysis within 1 week of transplanta tion. The incidence of cytomegalovirus was 13%; between December 1989 and D ecember 1992, it was 17%, and between January 1993 and December 1996, it wa s 12%. The incidence of early Epstein-Barr virus-related posttransplant lym phoproliferative disorder (PTLD) was 9%; between December 1989 and December 1992, it was 17%, and between January 1993 and December 1996, it was 4%. A ll of the early PTLD cases were treated successfully with temporary cessati on of immunosuppression and institution of antiviral therapy, without patie nt or graft loss. Conclusions. These data demonstrate the short- and medium-term efficacy of tacrolimus-based immunosuppression in pediatric renal transplant recipients , with reasonable patient and graft survival, routine achievement of steroi d and anti-hypertensive medication withdrawal, gratifying increases in grow th, and, with further experience, a decreasing incidence of both rejection and PTLD.