[Bone marrow graft: graft versus host reaction and rejection]

Area of Science:

• Immunology
• Transplantation Medicine
• Hematology

Background:

• Graft versus host disease (GVHD) is a significant challenge in allogeneic bone marrow transplantation, occurring in over 50% of HLA-identical transplants.
• GVHD can manifest as acute or chronic syndromes, contributing to 10-20% of transplant-related mortality.
• T lymphocytes targeting minor histocompatibility antigens are key mediators of GVHD.

Purpose of the Study:

• To review the challenges and current strategies in preventing graft versus host disease (GVHD) after allogeneic bone marrow transplantation.
• To explore the mechanisms of GVHD and graft rejection.
• To discuss emerging methods for preventing graft failure in the context of GVHD.

Main Methods:

• Review of existing literature on graft versus host disease (GVHD) mechanisms and prevention.
• Analysis of T cell depletion strategies and their impact on graft failure.
• Examination of methods to counteract host residual immunity and prevent graft rejection.

Main Results:

• T cell depletion of bone marrow is effective in enabling HLA-mismatched transplants but is associated with 10-20% graft failure.
• Graft failure in HLA-incompatible transplantations may result from the absence of donor T cell-mediated anti-rejection effects.
• Host residual immunity, involving cytotoxic T lymphocytes and natural killer cells, mediates graft rejection.

Conclusions:

• Preventing graft failure in allogeneic bone marrow transplantation requires addressing host residual immunity.
• Investigational approaches include enhanced chemotherapy, irradiation, and monoclonal antibody infusions targeting lymphoid cells.
• Further research is needed to optimize GVHD prevention while minimizing graft failure risk.