Libman-Sacks endocarditis in SLE characteristically shows vegetations on which surface of which valve, and which complement-related laboratory finding is associated with active disease?

• A Ventricular surface of the aortic valve only, associated with ANCA positivity
• B Atrial surface of the mitral valve only, associated with normal complement levels
• C Both surfaces (atrial and ventricular) of the mitral valve, associated with antiphospholipid antibodies and consumed complement (low C3/C4) ✓
• D Tricuspid valve in IV drug users, associated with positive blood cultures

Explanation

Libman-Sacks (non-infective verrucous) endocarditis in SLE classically involves the mitral valve and produces small, sterile vegetations on BOTH the atrial and ventricular surfaces of the leaflets (unlike rheumatic endocarditis which affects the line of closure on the atrial surface). It is strongly associated with antiphospholipid antibodies (aPL), which mediate endothelial injury and thrombosis. Active SLE causes immune complex deposition and complement consumption — hypocomplementemia (low C3, C4, CH50) is a serologic marker of lupus activity, including nephritis.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.