A Long-term Remission of a Recurrent Acute Lymphoblastic Leukaemia with Donor Leukocyte Infusions after Allogeneic Peripheral Blood Stem Cell Transplantation

This case report describes a patient with recurrent and refractory acute lymphoblastic leukaemia (ALL-L3), who relapsed four months after a HLA identical allogeneic Peripheral Blood Stem Cell (PBSC) transplantation; he was treated after relapse with intensive chemotherapy and then he received leukocyte infusion from her sibling donor. A long term Complete Remission (CR) was achieved, with complete chimerism and without signs of chronic GVHD. Thirteen months after Donor Leukocyte Infusion (DLI), he developed a relapse (4% blasts in BM), and a second infusion of leukocytes with the same chemotherapy schedule was performed. Six months after the second DLI the patient is alive. Since responses to Donor Lymphocyte Infusions (DLI) are uncommon in ALL, the possible causative factors for this unusual response are discussed.