Which antibody titer rises during allergy ?

Options

A. Immunoglobulin A
B. Immunoglobulin G
C. Immunoglobulin M
D. Immunoglobulin E

Answer

To determine which antibody titer rises during an allergy, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Allergies**:
- Allergies are exaggerated immune responses triggered by specific substances known as allergens. Common allergens include pollen, dust, and certain foods.

2. **Identifying Antibodies**:
- The immune system produces different types of antibodies (immunoglobulins) in response to various antigens. The main types of antibodies include:
- Immunoglobulin A (IgA)
- Immunoglobulin G (IgG)
- Immunoglobulin M (IgM)
- Immunoglobulin E (IgE)

3. **Role of Immunoglobulin E (IgE)**:
- IgE is specifically associated with allergic reactions. When an allergen enters the body, it binds to IgE antibodies that are attached to mast cells and basophils. This binding triggers these cells to release histamines and other chemicals, leading to the symptoms of an allergy (e.g., sneezing, rashes).

4. **Evaluating the Options**:
- **Immunoglobulin A (IgA)**: This is primarily found in mucosal areas and secretions (like saliva and tears), and is not involved in allergic reactions.
- **Immunoglobulin G (IgG)**: While it plays a role in the immune response, it is not specifically associated with allergies.
- **Immunoglobulin M (IgM)**: This is the first antibody produced in response to an infection but is not specifically linked to allergic reactions.
- **Immunoglobulin E (IgE)**: This is the correct antibody that rises during allergic reactions.

5. **Conclusion**:
- The antibody titer that rises during an allergy is **Immunoglobulin E (IgE)**.

### Final Answer:
**Immunoglobulin E (IgE)**

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