Elitek-rasburicase: an effective means to prevent and treat hyperuricemia associated with tumor lysis syndrome, a Meeting Report, Dallas, Texas, January 2002.

Renal precipitation of uric acid associated with tumor lysis syndrome (TLS) is a major complication in the management of leukemia, lymphoma, and other drug-sensitive cancers. Management of hyperuricema has historically consisted of administration of allopurinol, hydration, alkalinization to maintain pH between 7.0 and 7.3, and in some cases diuresis. Allopurinol, a xanthine analogue, blocks xanthine oxidase and formation of uric acid. Urate oxidase converts uric acid to allantoin, which is 5-10 times more soluble than uric acid. Homo sapiens cannot express urate oxidase because of a nonsense mutation. Urate oxidase was initially purified from Aspergillus flavus fungus. Treatment with this nonrecombinant product had been effective in preventing renal precipitation of uric acid in cancer patients, but was associated with a relatively high frequency of allergic reactions. This enzyme was recently cloned from A. flavus and is now manufactured as a recombinant protein. Clinical trials have shown this drug to be more effective than allopurinol for prevention and treatment of hyperuricemia in leukemia and lymphoma patients. This drug has been approved in Europe as well as the US and several clinical trials are in progress to further determine its clinical utility in other patient subsets. The purpose of this meeting was to discuss usefulness of recombinant urate oxidase, also known as rasburicase, Fasturtec, and Elitek, for the management of TLS in certain cancer patients.

Burkitt's lymphoma developing in a 7-year-old boy with hyper-IgE syndrome.

We report a case of Burkitt's lymphoma developing in a 7-year-old boy with hyper-IgE syndrome. This is the third reported case of malignancy in the hyper-IgE syndrome. The other two cases were an 18-year-old man with Hodgkin's disease and a 10-year-old girl with histiocytic lymphoma. The patient developed retroperitoneal Burkitt's lymphoma with probable metastasis to the brain. His short life was characterized by recurrent staphylococcal skin, middle ear, and lung infections associated with extremely elevated serum concentrations of IgE. There was also an associated disturbance of bone metabolism with osteoporosis and pathologic fractures and absence of parathormone, findings that have been observed in other patients with hyper-IgE syndrome and other forms of T cell immunodeficiency. At the age of 5 years, inadequate B cell responses to immunization with antigens derived from diphtheria, tetanus, and Haemophilus influenzae type b organisms and with the OX174 bacteriophage were demonstrated in the patient. In his terminal state his in vitro lymphocyte analysis demonstrated findings of anergy. Although the precise immunologic defect in hyper-IgE syndrome is unknown, these cases of associated malignancy stress the role that a completely normal immune system plays in preventing the premature appearance of cancer.