A patient with systemic lupus erythematosus has antibodies to double-stranded DNA (anti-dsDNA). The primary mechanism by which these antibodies cause glomerulonephritis is:

• A Direct complement-independent antibody-mediated cytotoxicity to podocytes
• B Molecular mimicry between dsDNA epitopes and GBM collagen
• C Formation of DNA-anti-dsDNA immune complexes depositing in the glomerulus and activating complement ✓
• D ANCA-mediated destruction of glomerular endothelium

Explanation

In lupus nephritis, anti-dsDNA antibodies form immune complexes with circulating or planted nuclear antigens (chromatin/DNA) in the glomerulus. These immune complexes activate complement (C1q, C3, C4), recruit neutrophils and monocytes, and cause glomerular injury. Full-house immunofluorescence (IgG, IgM, IgA, C3, C1q) is characteristic. ANCA is associated with AAV, not SLE.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.