PRIOR CONCURRENT THERAPY: Biologic therapy: Prior autologous stem cell transplantation allowed No prior allogeneic stem cell transplantation No other concurrent immunomodulating agents Chemotherapy: See Disease Characteristics Prior induction or consolidation therapy allowed No concurrent chemotherapy Endocrine therapy: At least 24 hours since prior corticosteroids No concurrent steroids Radiotherapy: Not specified Surgery: Not specified Other: No concurrent alternative therapy (e.g., laetrile, Brudzinski's treatment, etc.)