Name Surname Email address MP number Speciality Region 1. True or false:Platelet activating factor (PAF) is a central mediator in sustaining the chronic inflammation and pruritic characteristics of chronic spontaneous urticaria (CSU) True False 2. What is the role of PAF in the pathogenesis of CSU? A. Stimulates IgE production directly B. Inhibits cytokine release C. Activates eosinophils exclusively D. Induces mast cell degranulation, increases vascular permeability and promotes chemotaxis of inflammatory cells 3. What enzyme is responsible for the breakdown of PAF in the body? A. Acetylcholinesterase B. PAF-acetylhydrolase (AH) C. Cyclooxygenase-2 D. Histamine methyltransferase 4. Which of the following cell types release PAF and express the PAF receptor in CSU? A. Keratinocytes B. Erythrocytes C. Mast cells D. Osteoblasts 5. What key structural feature enables PAF to exert both autocrine and paracrine effects in CSU? A. Its long half-life in plasma B. Its ability to bind histamine receptors C. The expression of PAFR on multiple immune and endothelial cells that release PAF D. Its conversion to leukotrienes 6. Elevated PAF levels in CSU patients have been mostly associated with. A. Increased antihistamine responsiveness B. Shorter urticaria duration C. Resistance to H1-antihistamines D. Increase in PAF-AH levels 7. How does PAF contribute to neural activation and pruritus in CSU? A. By triggering histamine release from histamine-releasing cells B. Through direct nerve stimulation C. Via IL-17 receptor activation D. Through inhibition of sensory neuron signalling 8. Which of the following best describes rupatadine’s mechanism of action relevant to CSU? A. Selective IL-17 receptor blockade B. Dual H1-antihistamine and PAF receptor antagonist C. Mast cell stabiliser D. COX-2 inhibition and leukotriene suppression 9. In studies comparing antihistamines, which agent inhibited PAF-induced mast cell degranulation in both LAD2 and lung mast cells? A. Desloratadine B. Levocetirizine C. Cetirizine D. Rupatadine 10. True or falsePAF contributes to CSU through non-IgE-mediated pathways, including the activation of inflammatory cells, modulation of vascular permeability, and both direct and indirect mast cell degranulation, as well as stimulation of sensory neurons True False
