]> 2026-07-31T09:41:22+00:00 WBR0276 0 en Eosinophils activate macrophages to phagocytose the infectious agent T-cells activate macrophages to phagocytose the tubercle bacillus The infectious agent undergoes phagocytosis by alveolar macrophages Activated macrophages fuse and become multinucleated giant cells that constitute a granuloma to phagocytose and contain the infection Infected macrophages release IL-2 and IL-4 Infected macrophages release IL-12, which stimulates the formation of Th1 cells. IL-1 activates the Th1 cells and leads to fever. Th1 cells initiate the cell-mediated immunity needed to kill ''M. tuberculosis''. Destruction by cytotoxic T-cells results in coagulative necrosis. Destruction by cytotoxic T-cells results in caseous, not coagulative, necrosis. Activated neutrophils fuse to become multinucleated giant cells Activated macrophages, not neutrophils, fuse to become multinucleated giant cells. Pathology A 28-year-old man presents to the physician’s office for routine pre-employment check-up. During history-taking, the patient states that he grew up in Asia and immigrated to USA at the age of 20. The physician administers an intradermal injection of tuberculin skin test in the patient's left forearm, and the patient is instructed to follow-up in 2 days. When the patient returns, the site of his injection demonstrates a 16 mm erythematous, raised induration. Upon further questioning, the patient denies receiving a BCG vaccine in the past. When the patient asks why he did not develop any symptoms of his infection, the physician states that the majority of immunocompetent individuals are capable of containing the infection without developing any symptoms. Which of the following immunological changes occurs to contain this patient's infection? B Pulmonology General Principles 2020-10-28T00:01:51Z 2459150.5012847 WBR0276