Which type of immune response is responsible for the rejection of tissues/organs in the patient's body post transplantation?

Options

A. auto-immune response
B. humoral immune response
C. physiological immune response
D. cell-mediated immune response

Explanation

**Step-by-Step Solution:**

1. **Understanding Transplantation**: When an organ or tissue is transplanted from one person to another, the recipient's immune system may recognize the transplanted tissue as foreign. This is because the transplanted tissue may have different antigens than those present in the recipient's body.

2. **Role of Antibodies and Antigens**: The immune system uses antibodies to identify and attack foreign substances (antigens). Antigens are molecules that can trigger an immune response, and they are often found on the surface of cells.

3. **Immune Response Activation**: When a foreign tissue or organ is introduced into the body, the immune system detects the foreign antigens. This triggers an immune response where the body’s immune cells, particularly T cells, recognize these foreign antigens and initiate an attack against the transplanted tissue.

4. **Types of Immune Responses**: There are several types of immune responses:
- **Autoimmune Response**: The immune system mistakenly attacks the body’s own cells.
- **Humoral Immune Response**: This involves the production of antibodies by B cells against pathogens.
- **Cell-Mediated Immune Response**: This involves T cells directly attacking foreign cells.

5. **Identifying the Correct Response**: In the context of organ transplantation, the rejection of the transplanted tissue is primarily due to the **Cell-Mediated Immune Response**. T cells play a crucial role in identifying and attacking the foreign cells.

6. **Conclusion**: Therefore, the type of immune response responsible for the rejection of tissues or organs in the patient's body post-transplantation is the **Cell-Mediated Immune Response**.

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