Review Question - QID 214551

A 29-year-old woman with a history of asthma presents to the emergency department with a 5-week history of progressively worsening dry cough and shortness of breath on exertion. Her albuterol inhaler is no longer providing relief of her respiratory symptoms. She has also noticed painful bumps appearing on her shins over the last 4 months. Additional medical history includes irritable bowel syndrome. She is an electrical engineer, drinks socially, and has smoked 2 packs per day since she was 19 years old. On exam, she has a regular heart rate and rhythm and her lungs are clear to auscultation bilaterally. She has erythematous nodules on her bilateral anterior legs. Chest radiograph reveals bilateral hilar lymphadenopathy and microscopic analysis reveals the findings in Figure A. Which of the following mediators is responsible for the findings in Figure A?