Hyperuricemia after liver transplantation in children.

Uric acid may be involved in the development and progression of kidney diseases. Hyperuricemia is a common feature in adult liver transplant recipients but there is limited information in children. In order to estimate the incidence, predictors of hyperuricemia in pediatric liver transplant recipients, and to assess whether hyperuricemia may impact long-term renal function determined by measured GFR, we reviewed data of 70 children who received a first liver transplant between 1991 and 2005 (median follow-up 7.1 yr). Renal function tests performed annually included uric acid concentration, inulin and uric acid clearances. The cumulative incidence of hyperuricemia was 32% at 10-yr post-transplantation, mainly because of decreased urate excretion. The only factor significantly associated with an increased risk of hyperuricemia was older age. After adjustment for donor and recipient age, gender, primary liver disease, immunosuppression, and post-operative acute renal failure, hyperuricemia as time dependent variable tended to predict (p = 0.05) subsequent CRI. The control of serum urate concentration in eight of the 21 hyperuricemic patients either by nutritional management or by allopurinol was not followed by a significant GFR improvement. Hyperuricemia after liver transplantation in children is a frequent problem which needs further investigation.