The pediatric nephrologist's dilemma: growth after renal transplantation and its interaction with age as a possible immunologic variable.

Two important criteria for successful end-stage renal disease therapy in children are achievement of optimal growth and possession of a well-functioning renal transplant. We describe eight children with accelerated post-transplant growth. Accelerated and even catch-up growth was achievable if the transplant occurred at an early age (less than 9 years), the daily dose of prednisone was low (less than or equal to 0.24 mg/kg/d), and renal function was excellent (creatinine clearance greater than or equal to 89 mL/min/1.73 m2). However, the benefit to growth of transplanting a kidney in young children may be offset by reduced cadaver graft survival in children younger than 6 years. To study whether the less favorable graft survival was attributable to an increased immunologic responsiveness in the younger child, we examined three tests of nonspecific immune responsiveness, each of which, when increased, may indicate a propensity toward rejection: total T cell absolute number, T helper/suppressor ratio, and spontaneous blastogenesis. Each measurement was significantly increased in 20 uremic children 5 years old or younger, compared with 81 children 6 to 23 years of age. These data suggest that improved growth may be attained by transplanting a kidney in the young child with end-stage renal disease, but the young child may be at increased risk for rejection. This hypothesis suggests that for optimal rehabilitation, strategies should take into account the unique needs of the young child.