A 45-year-old woman with severe persistent asthma is started on omalizumab. This monoclonal antibody exerts its therapeutic effect by binding to:
- A IL-5, reducing eosinophil maturation and survival
- B Circulating IgE, preventing its binding to mast cells and basophils ✓
- C IL-4 receptor alpha, blocking IL-4 and IL-13 signaling
- D TSLP (thymic stromal lymphopoietin), an epithelial cytokine
Correct answer: B. Circulating IgE, preventing its binding to mast cells and basophils
Explanation
Omalizumab is a humanized monoclonal antibody that binds free IgE in circulation, preventing it from binding to the high-affinity Fc epsilon RI receptor on mast cells and basophils. This reduces allergen-triggered degranulation. It is used in moderate-to-severe allergic asthma. Mepolizumab and benralizumab target IL-5. Dupilumab targets IL-4Ralpha. Tezepelumab targets TSLP.
Reference: Katzung Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.