--Prior/Concurrent Therapy-- Biologic therapy: chronic transfusion therapy Chemotherapy: prior or concurrent cancer chemotherapy concurrent butyrate derivatives Endocrine therapy: concurrent corticosteroid therapy Radiotherapy: Not specified Surgery: Not specified --Patient Characteristics-- Hepatic: hepatic compromise Transaminases greater than 250 IU Renal: renal compromise Creatinine greater than 1.2 mg/mL (adults) Creatinine greater than 0.9 mg/mL (teenagers) Other: pregnant; Fertile patients with no effective contraception Poorly controlled seizure disorders other secondary conditions that might inhibit immune function