allogenen

Allogene, or allogeneic, is a term used in biology and medicine to describe cells, tissues, or organs obtained from a donor who is genetically different from the recipient but belongs to the same species. It is commonly contrasted with autologous sources, which come from the same individual, and syngeneic sources, which come from a genetically identical donor such as an identical twin.

Allogeneic transplantation is a principal context in which the term is used. This includes hematopoietic stem cell transplantation (bone marrow transplant) and solid organ transplantation. In allogeneic transplants, genetic differences between donor and recipient, particularly in the human leukocyte antigen (HLA) system, can provoke immune responses. Matching donor and recipient as closely as possible reduces rejection and immune complications, but complete matching is not always possible. Immunosuppressive therapy is often required to prevent rejection and to mitigate graft-versus-host disease (GVHD), a condition where donor immune cells attack the recipient’s tissues. The risk of GVHD tends to be higher with greater genetic disparity, especially in bone marrow–derived grafts.

Sources for allogeneic material include bone marrow, peripheral blood stem cells, umbilical cord blood, and, in the case of organs, kidneys, liver, lungs, and other tissues. Beyond transplantation, allogeneic cells and tissues are used in research and certain clinical therapies, including experimental allogeneic cell products and donor-derived cell lines.

Ethical and regulatory considerations emphasize donor informed consent, safety screening, infection risk management, and adherence to compatibility testing and post-transplant care.