What is the role of macrophages in granuloma formation?

Correct Answer: B

Rationale: The correct answer is B because macrophages play a crucial role in granuloma formation by engulfing antigens but failing to destroy them, leading to the formation of a cluster of immune cells to contain the persistent antigen. Macrophages present antigens to T cells, triggering an immune response. Other choices are incorrect as macrophages do not neutralize histamine, stimulate IgE production, or produce antibodies against antigens in the context of granuloma formation.

Correct Answer: E

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: B

Rationale: The correct answer is B: Lupus. Lupus is a systemic autoimmune disease that can affect multiple organs and tissues throughout the body, rather than being specific to a single organ. Multiple sclerosis (A) is a neurological autoimmune disease affecting the central nervous system. Diabetes (C) is an autoimmune disease that affects the pancreas. Hashimoto's thyroiditis (D) is an autoimmune disease targeting the thyroid gland. Lupus does not specifically target a single organ, making it the correct choice.

Correct Answer: B

Rationale: The correct answer is B because vaccines using attenuated HIV virus are not in a "phase II" clinical trial. Attenuated virus vaccines are risky due to potential reversion to virulence. A: True, Sub-Saharan Africa has the highest HIV prevalence. C: CD4+ counts decline during clinical latency. D: Viral RNA titer increases in the final stages.

Correct Answer: E

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.