Interpreting Immunoglobulin E Test Results

Immunoglobulin E (IgE) test results are interpreted by considering the reference range; higher levels may indicate an allergic reaction or parasitic infection. Lower immunoglobin E levels are explained in the MediSearch answer below:

What does it mean when immunoglobin e is low?

When immunoglobulin E (IgE) levels are low, it can indicate an underlying condition or immune dysregulation. Here are some key points about low IgE levels:

• Low IgE, defined as <2 kU/L, is called IgE deficiency or selective IgE deficiency when other immunoglobulin levels are normal [8], [9].
• It may be a marker for other immunodeficiency states like common variable immunodeficiency (CVID) [8], [10].
• Patients with low IgE levels have an increased risk of respiratory infections, autoimmune diseases, and malignancies [8], [11], [9].
• In some cases, low IgE can indicate an underlying B-cell or T-cell dysfunction [12].
• Low IgE has been associated with reduced immune responsiveness and impaired antibody production against certain pathogens [13], [10].
• It may serve as a marker of immune dysregulation, autoimmunity, and increased cancer susceptibility [14], [9], [15].
• The clinical significance depends on whether it is isolated (selective IgE deficiency) or accompanied by deficiencies in other immunoglobulin classes [8], [16].
  
  In summary, while low IgE alone may not always cause symptoms, it can be an indicator of underlying immune dysregulation or immunodeficiency, warranting further investigation and monitoring [8], [11], [9].

Immunoglobulins: An Overview

Immunoglobulins are protein molecules produced by plasma cells, a type of white blood cell. They play an essential role in the body's immune response by binding to foreign cells like bacteria and viruses to neutralise them and signal other immune cells to destroy them [1].

Immunoglobulin tests are diagnostic procedures that measure the levels of immunoglobulins, also known as antibodies, in your blood. These tests help evaluate your immune system's performance and help diagnose various conditions that affect the levels of immunoglobulins in your body [2].

Immunoglobulin E Tests

An Immunoglobulin E (IgE) test is a laboratory examination measuring the IgE level. The test involves taking a blood sample from the patient, which is then analysed in a laboratory.

A multitude of techniques are used to Identify the amount of IgE present. A few of these techniques include enzyme-linked immunosorbent assay (ELISA), immunofixation electrophoresis (IFE), or a Luminex-based multiplex serological assay. These methods use specific anti-human immunoglobulin antibodies or antigens to detect and quantify the presence of IgE in the blood sample [3, 4, 5].

The IgE test is widely used to diagnose allergic diseases, as elevated levels of IgE are typically found in individuals with allergies. It is also used to monitor the effectiveness of allergy treatments and to detect parasitic infections.[6]

Analysing Immunoglobulin E Results

High Immunoglobulin E Levels

As mentioned before, elevated levels of IgE are often associated with allergic diseases, parasitic infections, and certain immune deficiencies. For example, atopic eczema, allergic broncho-pulmonary aspergillosis, and helminthic infections elevate total serum IgE above 1000 IU/mL [6]. In a study of 352 patients with IgE >1000 IU/mL, less than 50% had these conditions, with the rest associated with asthma, allergic rhinitis, and food allergy [6].

Low Immunoglobulin E Levels

On the other hand, lowered IgE levels might indicate other immunodeficiency states, especially common variable immunodeficiency, which is characterised by recurrent infections, mainly respiratory-related, resulting in structural lung damage [7]. In one study analysing 4013 samples, 1.84% had serum IgE levels<2 kU/L, and of these, 56% had one or more classes of immunoglobulin above/below the reference range for age, and two had a new diagnosis of immunodeficiency [7].

Conclusion

In conclusion, both high and low IgE levels can indicate various health conditions, ranging from allergies and parasitic infections to immune deficiencies. Therefore, it's crucial to interpret IgE test results in the context of other clinical information and symptoms. If you have concerns about your IgE levels, it's recommended to consult with a healthcare professional for a comprehensive evaluation.