A 25-year-old woman complains of low-grade fever, fatigue, and persistent rash over her nose and upper chest. She also notes pain in her knees and elbows. A skin biopsy shows dermal inflammation and granular deposits of IgG and C3 complement along the basement membrane at the epidermal/dermal junction. Urinalysis reveals microscopic hematuria and proteinuria. The ANA is positive. The development of thromboembolic complications (e.g., deep venous thrombosis) in this patient is commonly associated with elevated serum levels of antibodies to which of the following antigens?

1/3rd of patients with SLE possess elevated concentrations of anti-phospholipid antibodies. It predisposes these patients to thromboembolic complications (stroke, pulmonary embolism, deep venous thrombosis, and poal vein thrombosis). The clinical course of SLE is highly variable and typically exhibits exacerbations and remissions. The overall 10-year survival rate approaches 90%(Because of early detection & management). -Antibodies against clotting factors (choice C) or fibrinolytic enzymes (choice D) are not involved in the clotting tendency associated with SLE. Diagnosis: Systemic lupus erythematosus