Hyperuricemia and tumor lysis syndrome in children with non-Hodgkin's lymphoma and acute lymphoblastic leukemia

Objective: This study aimed to examine the incidence, clinical characteristics, and outcome of hyperuricemia and tumor lysis syndrome (TLS) in children with non-Hodgkin's lymphoma (NHL) and acute lymphoblastic leukemia (ALL). Materials and Methods: This retrospective study included data from 327 patients (113 NHL and 214 ALL). Results: Hyperuricemia occurred in 26.5% and 12.6% of the patients with NHL and ALL, respectively. The corresponding figures for TLS were 15.9% and 0.47% (p=0.001). All hyperuricemic NHL patients had advanced disease and renal involvement was present in 53%. All hyperuricemic ALL patients had a leukocyte count >50,000 mm(3) at the time of diagnosis. Among the hyperuricemic NHL and ALL patients, 96.6% and 66.6% had LDH >= 500 UI/L, respectively. Treatment consisted of hydration and allopurinol; none of the patients received urate oxidase. Among the patients that developed TLS, 26.3% had laboratory TLS, 42.1% had grade I or II TLS, and 31.6% had grade III or IV TLS. Uric acid levels returned to normal after a mean period of 3.5+/-2.5 and 3.05+/-0.8 d in NHL and ALL groups, respectively. In all, 7% of the patients with hyperuricemia required hemodialysis. None of the patients died. Conclusion: In this series the factors associated with a high-risk for TLS were renal involvement in NHL and high leucocyte count in ALL. Management with allopurinol and hydration was effective in this group of patients with high tumor burden.