Department of Paediatric Oncology, Emma Children Hospital AMC, University of Amsterdam, Amsterdam, The Netherlands
*E-mail: h.vandenberg@amc.uva.nl
It is assumed that tumour lysis syndrome is primarily due to urate precipitation. Due to efficient urate depletion by rasburicase, it is suggested that severe renal damage will be absent [1]. Based on observation of a 7-year-old boy with Burkitts lymphoma, needing dialysis, we analysed calcium and phosphate metabolism using rasburicase. The index patient developed anuria, tetany and hyperphosphataemia (8.11 mmol). Creatinin rose from 38 to 188 µmol/l on dialysis. In order to optimise urate excretion, hyperhydration and alkalinisation were given during rasburicase administration (7 days). The first 25 consecutive patients treated with rasburicase were analysed for creatinin and phosphate/calcium disturbances in the first weeks of treatment. Twenty-three children had leukaemia or lymphoma, and two patients had bilateral nephoblastoma or hepatoblastoma.
Urate levels were below the detection limit in all serum samples. However, in three patients, urate serum levels <0.25 mmol/l were seen on the first day. In four children with B-cell lymphomas, creatinin levels became abnormal during the rasburicase treatment period, normalising within 5 days. During rasburicase treatment and alkalisation, hypocalcaemia was noted in eight patients. Hyperphosphataemia was noted in the first 3 days after initiating treatment. Hypophosphataemia occurred more often, i.e. in 10 cases. Hypophophataemia was noted relatively late (19 days after treatment started; median at 6 days). In five out of six B-cell cases hypophosphataemia occurred, which is more frequent than in children with other malignancies (P = 0.04).
Our data suggest that tubular damage is common at induction. Since urate depletion was efficient, calcium phosphate precipitation is probably a major cause of renal damage in TLS. As such alkalisation should be withheld using rasburicase.
H. van den Berg* & A. M. Reintsema
Department of Paediatric Oncology, Emma Children Hospital AMC, University of Amsterdam, Amsterdam, The Netherlands (*E-mail: h.vandenberg@amc.uva.nl)
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1. Goldman SC, Holcenberg JS, Finklestein JZ et al. A randomized comparison between rasburicase and allopurinol in children with lymphoma or leukemia at high risk for tumor lysis. Blood 2001; 97: 29983003.