Which of the Following Statements Concerning Allografts is TRUE

Question

Which of the following statements concerning allografts is TRUE?
A) They are the best type of transplants because they are not associated with rejection.
B) They induce strong type IV hypersensitivity reactions and must be treated with immunosuppressive drugs.
C) They always require complete destruction of the recipient's bone marrow cells.
D) They are impossible to perform because the antigens between donor and recipient are so different.
E) They are the rarest type of transplants.

Accepted Answer

Allografts are tissue transplants between genetically different members of the same species, and therefore they contain antigens that can stimulate an immune response in the recipient, leading to rejection. The rejection reaction is a type IV hypersensitivity reaction, which is mediated by T lymphocytes. Immunotherapy with drugs that suppress the recipient's immune system (immunosuppressive drugs) is necessary to prevent rejection.