Benefit of Granulocyte Colony-Stimulating Factor-Primed Donor Lymphocyte Infusion using Cryopreserved Cells for Patients with Acute Leukemia Who Relapsed Late after Hematopoietic Cell Transplantation

There is no standard therapy for relapse of acute leukemia after allogeneic Hematopoietic Cell Transplantation (allo-HCT). This study evaluated the efficacy of Granulocyte Colony-Stimulating Factor (G-CSF)-Primed Donor Lymphocyte Infusion (DLI) for patients with acute leukemia who relapsed after allo-HCT. We retrospectively reviewed 255 patients who received allo-HCT for acute leukemia/myelodysplastic syndrome. They were divided into two groups based on the CD34 + cell dose they received; patients in the lower CD34 + group received less than 6×10 6 cells/kg and those in the higher group received over 6×10 6 cells/kg. No significant differences were noted between the groups with respect to overall survival, relapse-free survival, and Graft- Versus -Host Disease (GVHD)-free/relapse-free survival. Among the 93 patients with relapse after allo-HCT, 39 patients received G-CSF-primed DLI. These 93 patients were classified into early or late relapse groups as defined by the median time to relapse. In the late relapse group, the one-year overall survival was significantly higher in the DLI group than in the non-DLI group (53.4±7.4% vs . 26.7±7.4%, p=0.039), whereas there were no differences in the early relapse group. In addition, the incidence of DLI-induced GVHD did not differ between the two groups. In conclusion, treatment with G-CSF-primed DLI after allo-HCT with a limited CD34 + cell dose is a feasible and effective option, which may replace a second HCT in late relapse patients.