In the resolution of acute inflammation, specialized pro-resolving mediators (SPMs) that halt neutrophil recruitment and promote macrophage efferocytosis are synthesized from which precursors?

• A Arachidonic acid generating thromboxane B2
• B Linoleic acid generating lipoxins
• C Sphingomyelin generating ceramide
• D Omega-3 fatty acids (EPA and DHA) generating resolvins and protectins ✓

Explanation

Specialized pro-resolving mediators (SPMs) including resolvins (E-series from EPA, D-series from DHA) and protectins/neuroprotectins (from DHA) are biosynthesized from omega-3 polyunsaturated fatty acids. These lipid mediators actively terminate acute inflammation by inhibiting further neutrophil recruitment, promoting neutrophil apoptosis, and enhancing macrophage phagocytosis of apoptotic cells (efferocytosis). Lipoxins (LXA4, LXB4) are derived from arachidonic acid and also have anti-inflammatory properties. This active resolution is why deficiency of omega-3 fatty acids promotes chronic low-grade inflammation.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.