A kidney transplant from an unrelated donor is referred to as what type of transplant?

The term for a kidney transplant from an unrelated donor is "allograft." This classification arises from the source of the transplant tissue. In allografts, the donor and recipient are of the same species but genetically different, which is the case with kidney transplants between unrelated individuals.

This type of transplant involves more significant considerations for compatibility, particularly regarding the human leukocyte antigen (HLA) system, as there is an increased likelihood of the recipient's immune system recognizing the transplanted organ as foreign and potentially rejecting it.

In contrast, a xenograft involves organ or tissue transplanted from a different species (for example, pig heart valves into humans), while an autograft refers to tissue transferred from one site to another within the same individual (such as skin or veins), and an isograft involves a graft from a genetically identical twin. Understanding these definitions is essential for grasping the various transplantation types and their implications in immunology and transplant medicine.