Tacrolimus (FK 506) after a pediatric renal transplant.

Rejection remains the overriding concern of pediatric renal transplant cent ers. Since 1995, 21 renal transplant recipients at the pediatric nephrology department of the Necker-Enfants Malades Teaching Hospital in Paris, Franc e, have been treated with tacrolimus (FK 506) because of an inadequate resp onse to triple combination therapy with azathioprine, prednisone, and ciclo sporin. Mean age was II years. Ciclosporin was stopped secondarily, while t acrolimus, azathioprine and prednisone were maintained. The reasons for swi tching from ciclosporin to tacrolimus were as follows: acute steroid-resist ant or recurrent rejection within one year of transplantation (n = 14), sev ere hirsutism and acne (n = 1), acute rejection and chronic transplant neph ropathy (n = 3), rejection and nephrosis recurrence (n = 2), and ciclospori n nephrotoxicity (n = I). after a mean follow-up of 13 months, 19 of the 21 transplants (90 %) were functioning, with a mean serum creatinine level of 102 mu mol/L. Three patients experienced a further episode of acute reject ion under tacrolimus therapy and were treated with bolus methylprednisolone , increased-dose tacrolimus, and mycophenolate mofetil in a dose of 500 mg/ m(2)/day. These three patients are currently doing well. The main side effe cts were transient nephrotoxicity (n = 6) reversible after tacrolimus dose attenuation, Pneumocystis carinii pneumonia (n = 1). and severe seizures (n = 1). An adolescent girl developed insulin-dependent diabetes mellitus. No cases of lymphoproliferative syndrome were recorded. Ten patients were not hypertensive at last follow-up. Mean tacrolimus dose was 0.25 mg/kg (0.10- 0.68 mg/kg) at treatment initiation and 0.18 mg/kg (0.04-0.39) after a few months. Residual levels were kept within the 5 to 9 ng/L range. This experi ence establishes tacrolimus as an effective and safe drug for the treatment of renal transplant rejection in pediatric patients.