Hyperuricemia beyond 1 year after kidney transplantation in pediatric patients: Prevalence and risk factors

Hyperuricemia is frequent among adult renal transplant recipients; however, data among pediatric kidney recipients are scarce. This study is designed to estimate the prevalence and risk factors of late post-transplant hyperuricemia in pediatric recipients. A retrospective observational multicenter study on 179 pediatric renal recipients (5–18 years) was conducted between April 2008 and January 2011 from five kidney transplant centers of Tehran, Iran. All recipients were followed up for more than 1 year (5.9 ±3.3 years) after transplantation. A total of 17686 blood samples were obtained for serum uric acid (SUA). The normal range of SUA was defined as SUA 1.86–5.93 mg/dl for children between 2 and 15 years in both genders; 2.40–5.70 mg/dl for girls aged >15 years; 3.40–7.0 mg/dl for boys aged >15 and more than 6 and 7 mg/dl in boys and girls older than 15 years old. The median age of the children was 13 years. Male recipients were more popular than female (male/female 59/41%). Hyperuricemia was detected in 50.2% of patients. Mean SUA concentration was 5.9±1.7 mg/dl and mean SUA concentration in hyperuricemic patients was 7.7±1.2 mg/dl. While at multivariate logistic regression elevated serum creatinine concentration (P<0.001) and the time span after renal transplantation (P=0.02) had impact on late post-transplant hyperuricemia. High cyclosporine level (C0 and C2) was not risk factor for huperuricemia. Late post-transplant hyperuricemia was found in about half of pediatric renal recipients, and was associated with impaired renal allograft function.