Transplants in Immunology

These flashcards cover key concepts related to transplants in immunology, including definitions, mechanisms, and types of rejection.

What is an autograft?

Tissue moved from one part of a person’s body to another part of the same person’s body.

What is a syngraft?

Tissue or organ transplanted from one member of a species to another genetically identical member.

What is an allograft?

Graft of tissue from a genetically different member of the same species.

What is a xenograft?

Transplant (graft) between different species.

What is the major role of Human Leukocyte Antigens (HLA)?

To help T Cells discriminate between self and non-self.

What happens when T Cells recognize protein products on transplanted tissue as non-self?

Rejection of the transplanted tissue occurs.

What are Class I HLA molecules primarily expressed on?

Most nucleated cells of the body.

What do Class II HLA molecules present antigen to?

Helper T Lymphocytes (CD4+).

What is a common allo- and autograft tissue?

Bone.

Why is HLA compatibility not considered for heart transplants?

Due to the urgency of the transplant.

What leads to hyper-acute rejection of a graft?

Preformed host antibodies to graft antigens.

What is graft versus host disease (GVHD)?

A condition where transfused lymphocytes recognize host antigens as foreign and react immunologically against them.

What characterizes acute graft rejection?

Host T Cells react to transplanted HLA antigens, occurring up to about 10 days after transplant.

What can chronic rejection lead to?

Slow continual loss of organ function.

What is essential for successful lung transplant matching?

Identical bronchial circumferences between donor and recipient.

What is the risk factor for developing GVHD?

Receiving allogenic or autologous bone marrow grafts.