Patients will be hospitalized at the beginning of the study. During this time, blood will be drawn at 3-week intervals and a bone marrow examination will be repeated 3 months after treatment has begun. Additional tests, including X-rays may be required. After hospital discharge, patients will be followed on an outpatient basis at 3-month intervals. The patients own physician will perform blood tests weekly and kidney and liver function tests every 2 weeks during cyclosporine therapy. Transfusions may be required initially.