Which cytokine is the principal mediator of the acute phase response, responsible for inducing fever, hepatic acute phase protein synthesis, and leukocytosis?
- A IL-4
- B IL-10
- C IL-1, IL-6, and TNF (acting together) ✓
- D TGF-beta
Correct answer: C. IL-1, IL-6, and TNF (acting together)
Explanation
The systemic acute phase response is driven by the triad of IL-1, IL-6, and TNF-alpha, secreted by activated macrophages. IL-6 is the primary inducer of hepatic acute phase proteins (CRP, fibrinogen, serum amyloid A). IL-1 and TNF act on the hypothalamus to induce fever via prostaglandin E2. Together they also stimulate bone marrow to increase neutrophil production. IL-4 and IL-10 are anti-inflammatory; TGF-beta promotes fibrosis.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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