Immunoglobulin E (IgE)

What sample is needed for Immunoglobulin E (IgE)?

• The best sample is fresh serum.

What are the indications for Immunoglobulin E (IgE)?

1. Used to detect allergic diseases.
2. Advised when the patient has:
   1. Itching of the skin and itching of the eyes.
   2. Urticaria and hives.
   3. Asthma and difficulty in breathing.
   4. Skin diseases like eczema.
   5. A cough, congestion.
   6. Sneezing.
   7. Persistent diarrhea, nausea, and vomiting.
3. Diagnosis of IgE-myeloma.
4. For the possibility of parasitic diseases.

 How will you discuss the structure of the Immunoglobulin E (IgE)?

1. IgE is a monomer form with a molecular weight of 190,000 and 7S.
2. It has an extra domain in the constant portion.
3. It has:
   1. Two epsilon (ε) heavy chains.
   2. One pair of kappa (κ) or lambda (λ) chains.
4. Its Fc region binds strongly to the receptors on the mast cells, basophils, along with antigens.

What are the facts about Immunoglobulin E (IgE)?

1. It is 0.004 % of the total immunoglobulins.
2. Its half-life is 2 days.
3. It is mainly involved in type-1 hypersensitivity reactions.
4. It cannot activate the complement system via the classical pathway.
5. It is present in a healthy person’s serum at extremely low concentrations.
6. It attaches to the receptors on basophils and mast cells.

7. Low-affinity receptors are present on the surface of B-lymphocytes and eosinophils.
8. It can not cross the placental barrier.

What is the normal Value of Immunoglobulin E (IgE)?

Source 1

• To convert into SI unit x 1.0 = kIU/L

Another source

• 150 ng/ml on the topic (non-allergic) person.
• or  .002 to 0.2 mg/dl
  • Values vary because of the methodology used.

What are the causes of raised Immunoglobulin E (IgE) levels?

1. Allergic diseases like asthma and skin diseases.
2. Asthma (It is positive in 60% of the patients).
3. Parasitic infestation (Ascariasis, visceral larva migrans, hookworm, Echinococcus, and schistosomiasis).
4. Multiple myeloma produces monoclonal IgE.
5. Hyper IgE syndrome.
6. Hay fever (30% of the patients).
7. Atopic eczema.

What are the conditions with normal or low IgE levels?

• Sometimes, in asthma.

What are the causes of decreased Immunoglobulin E (IgE)?

1. Agammaglobulinemia.
2. Hereditary deficiencies.
3. Non-IgE myeloma.
4. Ataxia-telangiectasia.