NETs (neutrophil extracellular traps) are chromatin fibres decorated with granule proteins released by neutrophils. In which of the following scenarios are NETs MOST detrimental rather than protective?

• A Systemic lupus erythematosus — NETs expose nuclear antigens driving anti-dsDNA autoantibody formation ✓
• B Gram-positive bacteraemia — NETs trap and kill circulating staphylococci
• C Fungal pneumonia — NETs immobilise Aspergillus hyphae in airways
• D Parasitic infection — NETs help kill large helminth larvae

Explanation

While NETs are beneficial for entrapping microbes, in SLE they become pathogenic: defective NET clearance (due to DNase-1 deficiency or anti-NET antibodies) exposes nuclear antigens (dsDNA, histones) to autoreactive B cells and plasmacytoid dendritic cells, amplifying interferon-α production and driving lupus nephritis. NETs in options B, C, and D represent physiological antimicrobial roles.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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