Damage to thymus in a child may lead to

Options

A. loss of cell mediated immunity
B. loss of antibody mediated immunity
C. a reduction in the amount of plasma proteins
D. a reduction in the haemoglobin content in blood

Answer

**Step-by-Step Solution:**

1. **Understanding the Role of the Thymus:**
- The thymus is a specialized organ where T lymphocytes (T cells) mature. It plays a crucial role in the immune system, particularly in developing cell-mediated immunity.

2. **Production of Lymphocytes:**
- Both B and T lymphocytes are produced in the bone marrow. However, T cells migrate to the thymus for maturation.

3. **Function of T Cells:**
- Once matured in the thymus, T cells are responsible for cell-mediated immunity. This means they can identify and attack infected cells in the body.

4. **Consequences of Thymus Damage:**
- If the thymus is damaged in a child, the maturation of T cells will be impaired. This leads to a significant reduction in the number of functional T cells.

5. **Loss of Cell-Mediated Immunity:**
- The primary consequence of thymus damage is the loss of cell-mediated immunity. This means the body will struggle to respond effectively to intracellular pathogens, such as viruses.

6. **Evaluating Other Options:**
- Loss of antibody-mediated immunity: This is primarily the role of B cells, which are not directly affected by thymus damage.
- Reduction in plasma protein: This is not related to T cell function.
- Reduction in hemoglobin: This is unrelated to the immune function of T cells.

7. **Conclusion:**
- Therefore, the correct answer is that damage to the thymus in a child may lead to a loss of cell-mediated immunity.

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