Question

To minimize organ transplant rejection, which type of molecules must be cross-matched between the donor and the recipient?

1. Major histocompatibility complex (MHC)
2. Antibodies
3. T lymphocytes
4. HLA antigens

Answer 1

To reduce organ transplant rejection, MHC molecules or HLA antigens must be cross-matched between the donor and recipient, as they are central to the immune response that can lead to rejection.

Step-by-step explanation:

To minimize organ transplant rejection, the type of molecules that must be cross-matched between the donor and the recipient are the Major Histocompatibility Complex (MHC) molecules, also known as HLA antigens. These molecules play a critical role in distinguishing self from non-self and are the major cause of transplant rejection. Matching MHC molecules between donor and recipient is key to reducing organ rejection, which is why MHC tissue typing is performed before a transplant. Even with a good MHC match, transplant recipients typically require immunosuppressive therapy to further prevent rejection.

Different MHC class I molecules between donor and recipient can lead to organ rejection because the recipient's immune system may recognize the transplanted organ as foreign and mount a cytotoxic T cell response, potentially causing rejection. Therefore, the more similar the MHC typing between donor and recipient, the greater the chance of the transplant being accepted and the lower the risk of rejection.