Graft-versus-leukemia reactions in allogeneic chimeras

Area of Science:

• Immunology
• Hematology
• Oncology

Background:

• Allogeneic stem cell transplantation (SCT) relies on the graft-versus-leukemia (GVL) effect mediated by donor immune cells to eliminate leukemia.
• Donor lymphocyte infusions (DLIs) can induce remissions in patients with relapsed leukemia post-SCT, harnessing this GVL effect.

Purpose of the Study:

• To review the clinical utility of DLIs for leukemia relapse.
• To discuss the mechanisms underlying GVL reactions and associated challenges.
• To explore novel strategies for improving DLI efficacy and safety.

Main Methods:

• Review of multicenter surveys and existing literature on DLI therapy for leukemia.
• Analysis of factors influencing GVL effectiveness in different leukemia types.
• Examination of strategies including cytokine stimulation, suicide gene-modified T cells, and HLA-mismatched donors.

Main Results:

• DLT shows greatest efficacy in chronic myelogenous leukemia (CML), with less pronounced effects in acute leukemias and myeloma.
• Infections and graft-versus-host disease (GVHD) are significant complications of DLT.
• Emerging strategies aim to separate GVL from GVHD and enhance anti-leukemia responses.

Conclusions:

• DLIs are a valuable tool for relapsed leukemia post-SCT, particularly CML, but GVHD remains a challenge.
• Future directions include adoptive immunotherapy with T cells targeting leukemia-specific antigens and utilizing alloreactive natural killer cells.
• Advanced approaches promise improved outcomes for leukemia and lymphoma patients undergoing SCT.