Donor Lymphocyte Infusions for Patients with Relapsed Leukemia after Allogeneic Hematopoietic Stem Cell Transplantation: a 10-year Experience of Seoul National University Hospital

ABSTRACT

BACKGROUND: Donor lymphocyte infusion (DLI) has been established as a salvage therapy for patients with relapsed leukemia after allogeneic hematopoietic stem cell transplantation (HSCT). However, its benefit can be limited by the development of graft-versus-host disease (GVHD) or marrow aplasia. METHODS: We retrospectively analyzed the data from 39 patients that received DLI for relapsed leukemia after HLA-matched, related HSCT between 1995 and 2005 at Seoul National University Hospital. RESULTS: The diagnoses were CML (n=8), AML (n=19) and ALL (n=12). Ten patients had received non- myeloablative HSCT (AML=9, ALL=1). Complete remission after DLI was achieved in 6 (75%) cases with CML, 5 cases (29%) with AML and 5 cases (41%) with ALL. The two-year progression-free survival was 60% in CML patients, but 8.1% in non-CML patients (P=0.01). In addition, better overall survival (OS) was shown in CML patients than in non-CML patients (2-year OS, 68% in CML; 10% in non-CML, P=0.01). The durable remission for more than three years after DLI was confirmed in five patients (one AML patient for 88 months, one ALL patient for 54 months, three CML patients for 38, 47 and 53 months). Acute GVHD (> or =Grade II) developed in 14 patients (35.9%). Prolonged marrow aplasia (neutrophil count <500/micro L, platelet count <20,000/micro L) developed in fourpatients (10.3%). CONCLUSION: DLI was the effective salvage therapy for relapsed CML after allogeneic HSCT, whereas limited effects were shown for AML and ALL with durable remission in only a few patients.