Decreased fibrinolytic capacity and increased von Willebrand factor levels as indicators of endothelial cell dysfunction in patients with lupus anticoagulant.

Over a 6-year period, 10 patients with lupus anticoagulant activity were seen. A history of thrombotic disease was found in 6 patients, but only 3 had systemic autoimmune disease. Reduced fibrinolytic activity after venous occlusion was found in 9 subjects, but only 4 had high von Willebrand factor levels. These changes were unrelated to inflammatory activity, which was ruled out by normal serum protein electrophoresis in all but one case. Human brain thromboplastin dilution test was pathological in all subjects with depressed fibrinolytic activity. These two tests may prove to be of value to single out those LA patients with highest risk for development of thromboembolic disease.