Neutrophil extracellular traps (NETs) are composed of:

• A Polymerised actin filaments secreted during active phagocytosis
• B Decondensed chromatin and antimicrobial proteins extruded from neutrophils ✓
• C Complement-coated fibrin strands trapping bacteria to vessel walls
• D Toll-like receptor complexes released as exosomes during systemic sepsis

Explanation

NETs are webs of extracellular decondensed DNA (histones) studded with antimicrobial granule proteins (elastase, MPO, calprotectin) that trap and kill extracellular pathogens. They are released by neutrophils undergoing NETosis, a form of cell death distinct from apoptosis and necrosis requiring citrullination of histones by PAD4. While protective, NETs also contribute to immunothrombosis in COVID-19, SLE, and ANCA vasculitis.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.