A patient with a resolving abscess undergoes wound healing. Which cytokine is primarily responsible for the transition from neutrophil-predominant acute inflammation to the macrophage-dominated resolution phase?
- A IL-8 (CXCL8)
- B IL-4 and IL-13 driving M2 macrophage polarization ✓
- C TNF-alpha
- D Leukotriene B4 (LTB4)
Correct answer: B. IL-4 and IL-13 driving M2 macrophage polarization
Explanation
Resolution of inflammation requires switching from pro-inflammatory M1 macrophages (activated by IFN-γ, LPS) to anti-inflammatory/reparative M2 macrophages. IL-4 and IL-13 (from T helper 2 cells, mast cells, and eosinophils) are the principal drivers of M2 (alternative) activation, promoting phagocytosis of apoptotic neutrophils (efferocytosis), collagen synthesis, and tissue repair. IL-8/CXCL8 and LTB4 are neutrophil chemoattractants that sustain acute inflammation; TNF-α is pro-inflammatory.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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