T cell-depleted allogeneic bone marrow transplantation from a partially HLA-mismatched unrelated donor for progressive chronic lymphocytic leukemia and fludarabine-induced bone marrow failure

A 49-year-old man with a 3-year history of chronic lymphocytic leukemia (CLL, stage B at diagnosis) responded well to four courses of fludarabine, but developed marrow failure and prolonged pancytopenia lasting 9 months following the fifth course. Fludarabine therapy could not be continued due to pancytopenia, eventually resulting in disease progression. Bone marrow transplantation from an unrelated donor mismatched at one DRB1 locus and both DQB1 loci was performed as salvage therapy. The marrow was depleted of T cells with Campath-1G. Pre-transplant immunosuppression was enhanced with 600 cGy total lymphoid irradiation and Campath-1G infusions in addition to 120 mg/kg cyclophosphamide and 1200 cGy fractionated total body irradiation. Cyclosporine alone was used as post-transplant immunosuppression. Neutrophils reached 0.5 x 10⁹/l on day 14 and platelets 50 x 10⁹/l on day 40. No acute graft-versus-host disease was seen. Bulk disease detected on CT scanning prior to BMT was found to have disappeared 10 weeks after BMT. The marrow showed residual disease (5% CD5⁺/CD19⁺ cells) 9 weeks after transplantation, which had decreased markedly at 13 (0.5%) and 26 (0.4%) weeks. The patient is currently alive and well 10 months after BMT with no clinically detectable disease. We conclude that BMT from an unrelated donor is a feasible treatment option in advanced CLL.