Effects of hyperuricemia on renal function in pediatric renal transplant recipients

Hyperuricemia is common in pediatric renal transplant recipients, and it is associated with poor allograft outcomes. Hyperuricemia occurs early after transplant and is associated with use of diuretics, cyclosporine therapy, a history of hyperuricemia, and decreased glomerular filtration rate. We aimed to investigate causes and effects of hyperuricemia on allograft outcomes in our patients.

There were 81 pediatric transplant patients (41 female and 40 male) included in the study. Demographic characteristics and laboratory parameters were recorded. Risk factors for hyperuricemia and the effects of plasma uric acid levels at 3, 6, 12, and 36 months on allograft outcomes were evaluated.

Mean age was 16.9 ± 5.6 years. Mean follow-up after transplant was 3.5 ± 0.47 years. Hyperuricemia was detected in 17.6% patients. A significant negative correlation was observed between 6-month uric acid level and 36-month glomerular filtration rate (r = -0.33, P = .04; r = -0.33, P = .017). A significant positive correlation between 3- and 6-month uric acid levels and 36-month plasma creatinine level was observed (r = -0.44, P = .01; r = -0.51, P = .001). There was no significant correlation between plasma uric acid level and body mass index, plasma lipid levels, use of diuretics, or immunosuppressive treatment (tacrolimus or cyclosporine).

Uric acid levels may have predictive value in the long-term assessment of renal function. Posttransplant hyperuricemia can be used as a long-term prognostic marker of poor renal outcome. Patients with hyperuricemia should be monitored closely for renal function.