American Board of Internal Medicine (ABIM) Certification Practice Exam

What is typically the range of serum IgE levels for Omalizumab use?

1. 10-30 U/mL

2. 20-100 U/mL

3. 30-700 U/mL

4. 700-1000 U/mL

The correct answer is: 30-700 U/mL

Omalizumab is a monoclonal antibody used in the treatment of severe allergic asthma and chronic spontaneous urticaria. It works by binding to IgE, the immunoglobulin involved in allergic responses, thereby preventing it from attaching to its receptors on mast cells and basophils. This leads to a reduction in the severity of allergic reactions. The typical serum IgE range for patients who are considered for Omalizumab therapy falls between 30 and 700 U/mL. This range is important because Omalizumab is most effective for individuals with moderate to high levels of IgE, which indicate a more severe allergic response that could benefit from this targeted therapy. Patients with serum IgE levels below 30 U/mL may not have significant allergy-related symptoms that would warrant the use of such a treatment, while levels above 700 U/mL could indicate a level of IgE that is typically associated with severe allergic disease. Therefore, the rationale behind this specific range of 30 to 700 U/mL is based on the therapeutic goals of managing allergy symptoms effectively while remaining within a safe and effective window for treatment with Omalizumab.