Clinical use of tacrolimus (FK-506) in infants and children with renal transplants.

Although cyclosporine (CsA)-based immunosuppressive regimens have been highly successful in renal transplantation in infants and children, their adverse influence on somatic growth, general appearance, and blood pressure are of particular importance in this population. Over the past 4 years, we have utilized tacrolimus (formerly FK-506) as the primary immunosuppressive agent in 43 unselected children and achieved 1-year and 3-year allograft survival rates of 96% and 85%, respectively. We have also used tacrolimus to rescue 14 of 19 (74%) renal allografts from CsA-resistant rejection. Corticosteroids were discontinued in 62% of non-rescue patients without increasing the risk of rejection or renal dysfunction over a mean follow-up time of 25 months. Tacrolimus monotherapy has been associated with improved body growth and less obesity, while tacrolimus alone or in combination with prednisone was virtually free of hirsutism or gingival hypertrophy, and posed a low risk for hypertension. A major disadvantage of this regimen may be an increased risk for viral infections and a benign form of posttransplant lymphoproliferative disease. This article describes the tacrolimus protocol utilized in our center and focuses on practical clinical issues including therapeutic monitoring, benefits, and major toxicity in children with renal allografts.