Hyperuricemia in preterm infants: clinical features and early rasburicase therapy

Hyperuricemia is implicated in neonatal acute kidney injury. Although rasburicase effectively lowers uric acid (UA) in malignancy-associated hyperuricemia, evidence in preterm infants is scarce.

We retrospectively studied 74 preterm neonates ( ≤ 32 weeks or <1500 g). Infants with hyperuricemia (serum UA levels ≥8 mg/dL; n = 20) received single-dose intravenous rasburicase (0.2 mg/kg). Serial clinical data were collected.

Median serum UA levels peaked on day 1 (5.0 mg/dL), declining by day 28 (1.6 mg/dL). Hyperuricemia occurred in 20 infants (27.0%). Rasburicase was administered at a median postnatal age of 3 days with a median UA level of 9.6 mg/dL, a median postmenstrual age of 25 weeks and body weight of 667 g at the time of treatment. Rasburicase reduced UA by >90% within 24 h, increased urine output, and normalized electrolytes (all p < 0.05). Exposure to rasburicase was associated with a significant reduction in serum UA, independent of postnatal age, with a significant time-by-treatment interaction. Blood urea nitrogen and creatinine levels improved by day 7. No adverse effects were observed.

Early rasburicase administration was associated with a marked reduction in serum UA levels and improvement in renal parameters without major adverse effects, suggesting a potential therapeutic role in preterm neonates.

Hyperuricemia contributes to neonatal acute kidney injury (AKI) and is closely linked to prematurity and illness severity. Although rasburicase is established for malignancy-associated hyperuricemia, evidence in preterm infants remains limited. This is the first study to evaluate the efficacy and safety of early rasburicase in extremely preterm infants with hyperuricemia. Early rasburicase administration resulted in a rapid uric acid reduction of >90% and an association with favorable changes in renal parameters without observed adverse effects. Our findings provide novel evidence supporting rasburicase as a potential therapeutic option in neonatal intensive care to reduce hyperuricemia-related AKI risk.