Organ Transplantation and rejection

INAM ULLAH

Topic: Transplantation

Transplantation refers to the act of transferring cells, tissues or organs from one site to another within individuals or between different individuals or between different species of genetically identical or not.

Transplantation

The tissue or organ transplanted is known as the transplant or graft.

The individual from whom the graft is obtained is known as the donor and the individual on whom it is applied known as recipient or acceptor.

Donor Accepter

Types of Grafts

Autograft

Isograft (Syngraft)

Allograft (Homograft)

Xenograft (Heterograft).

Autograft

• Tissue transplanted from one part of the body to another in the same individual. Also known as Autotransplants.

• It is always accepted.

Isograft

• Transplantation in which organs or tissues are transplanted from a donor to a genetically identical recipient (such as an identical twin). It is also known as Isotransplants.

• It is always accepted.

Allograft

• Allograft is a transplant of an organ or tissue between two genetically non-identical members of the same species.

Xenograft

• A transplant of organs or tissue from one species to another. An example is porcine heart valve transplant, which is quite common and successful.

Graft RejectionGraft vs. Host Disease Transplant Rejection

Acute GVHD

Chronic GVHD

Hyper Acute Rejection

Acute Rejection

Chronic Rejection

Graft vs. Host Disease

Caused by the reaction of grafted mature T-cells in the marrow inoculum with alloantigens of the host

Acute GVHDCharacterized by epithelial cell death in the skin, GI tract, and liver

Chronic GVHDCharacterized by fibrosis of one or more of these organs as well as the lungs

Transplant Rejection

Hyper Acute Rejection

Acute Rejection

Chronic Rejection

Endothelial cells release von Willebrand factor that mediate platelets adhesion

Endothelial cells lost the cell surface heparin sulfate proteoglycans that normally interact with antithrombin III to inhibit coagulation.