An IgE deficiency, specifically a selective IgE deficiency, is a condition characterized by significantly low levels of immunoglobulin E (IgE) in the blood while other immunoglobulin levels remain normal.
Understanding Selective IgE Deficiency
Here's a breakdown of what this means:
- Immunoglobulin E (IgE): IgE is an antibody primarily involved in allergic reactions and responses to parasitic infections.
- Selective Deficiency: This term indicates that only the IgE levels are affected; other immunoglobulins like IgG, IgG subclasses, and IgA are present at normal levels.
Defining Low IgE Levels
According to the reference, selective IgE deficiency is defined by an IgE level of less than 2.5 international units per milliliter (<2.5 IU/mL). This low level is considered clinically significant when other immunoglobulin levels are normal.
Key Characteristics of Selective IgE Deficiency
| Characteristic | Description |
|---|---|
| IgE Level | Significantly low (<2.5 IU/mL) |
| Other Immunoglobulins | IgG, IgG subclasses, and IgA are present at normal levels |
| Primary Impact | Reduced or absent IgE-mediated responses |
Practical Implications
- Reduced Allergic Responses: People with selective IgE deficiency may experience fewer or less severe allergic reactions compared to individuals with normal IgE levels.
- Potential for Unrecognized Parasitic Infections: IgE plays a role in defending against parasitic infections. A deficiency could lead to these infections going unnoticed or being more difficult to clear.
- Diagnostic Considerations: Selective IgE deficiency is diagnosed via blood tests that measure the levels of different types of immunoglobulins. The low IgE level must be confirmed while other immunoglobulin levels are normal.
Conclusion
In essence, an IgE deficiency, specifically selective IgE deficiency, means the body has a lower than normal level of IgE antibodies in the bloodstream, while other types of antibodies are normal. This could affect how the body reacts to allergies and parasitic infections.
