Without genetic modification, what is the main cause of rejection in xenotransplants?
A) Transfer of infection
B) Organs are the wrong size
C) The minor HLA antigens do not match
D) Pre-existing antibodies to alpha-galactosyl

Question

Quizplus · Accepted Answer

Organs of most species other than humans have alpha-galactosyl on their cell surfaces, and humans have pre-existing antibodies to the antigen, leading to hyperacute rejection. The organs are the correct size for transplantation, and the risk of transfer of infection is unknown at this point, since hyperacute rejection occurs before determination of transfer of infection could be made. HLA antigens are specific to humans, so an HLA match cannot be made. Genetic modification of the donor species can eliminate expression of alpha-galactosyl on the surface of the xenograft to reduce the chance of rejection.

Without Genetic Modification, What Is the Main Cause of Rejection