Question

Which of the following immune responses is responsible for rejection of kidney graft?

• A. Auto-immune response
• B. Humoral immune response
• C. Inflammatory immune response
• D. Cell-mediated immune response

Answer 1

The Correct Option is D

The rejection of a kidney graft or transplant rejection is primarily mediated by the immune response of the recipient. Understanding the immune system's role in this process is crucial for answering the question:

1. Cell-Mediated Immune Response: This type of response is primarily responsible for the rejection of transplanted organs like kidneys. In the cell-mediated immune response, T-cells, particularly cytotoxic T-cells, recognize and attack the foreign antigens present on the transplanted organ. Since the kidney graft comes from another individual (even if genetically related), the body's immune system may identify these cells as foreign and mount an attack against them.
2. Humoral Immune Response: While this involves B-cells and the production of antibodies, it is not the primary mechanism responsible for the acute rejection of organ transplants. Antibody-mediated rejection can occur but is more often associated with certain chronic rejection processes.
3. Auto-immune Response: This type of response is directed against the individual’s own cells due to a failure in recognizing self-antigens as "self." It is not directly involved in the rejection of a transplanted organ, which is considered "non-self" by the recipient’s body.
4. Inflammatory Immune Response: While inflammation is a component of the immune response and can occur during rejection, it is a secondary aspect resulting from the activation of immune responses and is not specific to the mechanism of kidney graft rejection.

Based on the above explanations, the correct option is the cell-mediated immune response, as it is the primary driver of acute rejection in organ transplantation scenarios.