Thrombotic cerebral arteriopathy in patients with the antiphospholipid syndrome.

OBJECTIVE: A distinctive type of chronic cerebral vasculopathy was identified in the small leptomeningeal arteries of patients with high levels of serum antiphospholipid antibodies. This study characterizes the vascular lesions and investigates their pathogenesis.
DESIGN: A comparative study of cerebrovascular disease in patients dying of systemic lupus erythematosus (SLE) and the antiphospholipid syndrome. PATIENTS: Cerebrovascular disease observed in autopsies on a patient with primary antiphospholipid syndrome and a patient with SLE and antiphospholipid syndrome was compared with findings on two SLE patients who did not have serum antiphospholipid antibodies and with findings on 15 patients having diseases in which pathological changes of meningeal arteries might be anticipated or are known to occur (six patients with hypertensive cerebrovascular disease, one patient with thrombotic thrombocytopenic purpura, seven patients with marantic or bacterial endocarditis, and one patient with a left ventricular mural thrombus). Multiple blocks of brain tissue were studied by serial histologic sections and histochemical and immunohistochemical methods. Immunofluorescent and electron microscopic (EM) studies were performed on kidneys and EM studies on brain and choroid plexus in each case of antiphospholipid syndrome.
RESULTS: Leptomeningeal arteries of antiphospholipid syndrome patients disclosed fibrin thrombi and widespread obstruction by a proliferation of intimal fibrous tissue or myointimal cells. The fibrous and cellular segments of obstructed arteries frequently contained fibrin thrombi and displayed varying stages of recanalization. In late stages of organization, fibrous webs were formed across arterial lumens. Obstructed arteries were traced to small infarcts localized to an underlying column of cortical gray matter. None of the tissues from antiphospholipid syndrome patients showed evidence of an active or healed inflammatory vasculitis or of vascular immune complex deposits. Recanalized thrombi, fibrous and cellular occlusions, and fibrous webs were not found in the leptomeningeal arteries of patients who did not have the antiphospholipid syndrome.
CONCLUSIONS: The cerebrovascular changes of the antiphospholipid syndrome are derived from a chronic thrombotic microangiopathy. The findings support the hypothesis that antiphospholipid antibodies can cause recurring episodes of intravascular thrombosis.