Sirs,

We appreciate the comments by Ghirardello et al. [1] concerning their experience with rasburicase in neonates with hyperuricemia and acute kidney injury (AKI). They reference their unpublished data and assert that the concomitant improvements in urinary output and serum creatinine observed in our study with the lowering of uric acid were likely the result of volume reconstitution, not a therapeutic effect of rasburicase [2].

Several tumor lysis syndrome studies demonstrating the utility of rasburicase in the absence of volume reconstitution have demonstrated significant improvement of serum creatinine with uric acid [35]. We cannot definitively state that rasburicase improved the renal function in our hyperuricemic infants with AKI. When these findings are taken together, the report by Ghirardello et al. contrasting published studies demonstrating a potential renal benefit of treatment with rasburicase identifies the need for a prospective study targeting uric acid reduction to prove or disprove its benefit to the infant with AKI.