Nephrotic Syndrome Associated with Libman-Sacks Endocarditis as a First Manifestation of Systemic Lupus Erythematosus: A Case Report and Review of the Literature

Abstract

Libman-Sacks endocarditis is a rare but well-recognized cardiac manifestation of systemic lupus erythematosus, characterized by sterile, verrucous vegetations on heart valves. We report an exceptional case of a 29 year old male patient who presented with profound nephrotic syndrome and mitral aortic endocarditis as the initial manifestation of previously undiagnosed systemic lupus erythematosus associated with antiphospholipid syndrome. The clinical presentation included inflammatory arthritis, constitutional symptoms, prolonged fever, and chronic inflammatory left subpalpebral cellulitis. Echocardiography revealed mitral and aortic valve thickening with fine vegetations on the aortic side of the posterior sigmoid cusp, along with significant mitral and aortic regurgitation. Immunological workup was strongly positive for antinuclear antibodies with a speckled pattern, IgG anti-cardiolipin antibodies, and IgG anti-beta-2-glycoprotein I antibodies. Renal biopsy was consistent with lupus glomerulonephritis. High dose corticosteroids combined with double antibiotic therapy led to significant clinical and biological improvement within 21 days. This observation is remarkable because cardiac involvement typically occurs years after systemic lupus erythematosus onset, whereas here it presented as an initial, aggressive manifestation in a male subject, associating renal involvement, endocarditis, and antiphospholipid syndrome. Treatment was based on a combination of antibiotics, corticosteroids, and synthetic antimalarials. This case highlights the importance of considering systemic lupus erythematosus in the differential diagnosis of culture negative endocarditis with nephrotic syndrome.

Keywords: Libman-Sacks endocarditis, nephrotic syndrome, systemic lupus erythematosus, antiphospholipid syndrome, case report