Allogeneic related donor hematopoietic stem cell transplantation for treatment of chronic lymphocytic leukemia.

Between 1980 and 1999, 25 patients with chronic lymphocytic leukemia (CLL) received related donor hematopoietic stem cell transplants. Median patient age was 46.6 years. Preparative regimens included busulfan (BU) plus cyclophosphamide (CY), CY plus TBI, and etoposide, CY plus TBI. Twenty-one donors were HLA-identical siblings, one was a DR mismatched sibling, and three were identical twins. Bone marrow was the source of hematopoietic stem cells in 22 cases and G-CSF stimulated peripheral blood in three cases. Most patients received methotrexate and cyclosporine for GVHD prophylaxis. Fourteen patients developed grades 2-4 acute GVHD and 10 developed clinical extensive chronic GVHD. Late clearance of CLL cells was associated with the development of chronic GVHD in one patient. Two patients had recurrent CLL. Nonrelapse mortality at day 100 was 57% for the seven patients conditioned with BU/CY and 17% for the 18 patients conditioned with TBI-containing regimens. Actuarial survival at 5 years for the 25 patients is 32%. All patients who received BU/CY died within 3 years of transplant. For the 14 patients transplanted since 1992 and who received TBI, actuarial 5-year survival is 56%. The maximum response of CLL to hematopoietic cell transplantation may be delayed, but long-term disease-free survival can be achieved.