A 30-year-old woman presents with butterfly rash, arthritis, serositis, and renal involvement. ANA is positive at 1:640. Which autoantibody pattern carries the highest specificity for systemic lupus erythematosus (SLE) AND correlates with disease activity and lupus nephritis?

• A Anti-Ro (SS-A) antibodies
• B Anti-histone antibodies
• C Anti-Smith (anti-Sm) antibodies
• D Anti-double-stranded DNA (anti-dsDNA) antibodies ✓

Explanation

Anti-dsDNA antibodies have dual significance in SLE: they are highly specific (>95%) for SLE among connective tissue diseases, and rising titers of anti-dsDNA correlate directly with disease activity and lupus nephritis flares because the antibodies form immune complexes with nucleosomal DNA that deposit in glomeruli and activate complement. Anti-Sm is highly specific but does not track activity. Anti-histone is the signature of drug-induced lupus. Anti-Ro is more characteristic of Sjögren syndrome and neonatal lupus (heart block).

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.