- Arterial or venous thrombosis.
- Recurrent pregnancy losses.
- Autoantibodies to phospholipid or β2-glycoprotein I.
- Lupus anticoagulant activity.
- Can occur independently or in association with systemic lupus erythematosus (SLE).
Antiphospholipid antibody syndrome (APS) is an acquired disorder associated with circulating autoantibodies to anionic phospholipids (eg, cardiolipin) and their protein binding complexes. The primary clinical manifestations of APS are thromboses, which can affect both the arterial and venous circulations, and pregnancy loss. APS can occur independently, in which case it is called primary APS, or it can develop in the setting of another autoimmune disease, usually SLE, in which case it is called secondary APS. The diagnosis of APS relies on recognition of its clinical presentation and detection of antiphospholipid antibodies either by enzyme immunoassays or by the presence of an anticoagulant (a “lupus anticoagulant”) in a phospholipid-dependent coagulation test, such as the Russell viper venom time. Treatment usually involves anticoagulation, the level of which is still debated but depends on clinical context.
Deep venous thrombosis (DVT) is the most common clinical manifestation of the hypercoagulability associated with primary or secondary APS. DVTs can be single or multiple and affect either large or small veins. Most common are DVTs in the lower extremities; pulmonary embolism complicates up to one third of lower extremity DVTs associated with APS. Thromboses associated with APS can involve any component of the venous circulation; APS can cause renal vein thrombosis, retinal vein occlusion, Budd-Chiari syndrome, and adrenal hemorrhage secondary to thrombosis of the adrenal veins.
APS-associated arterial disease is common and can affect the peripheral vascular, cerebrovascular, and cardiovascular circulations. The clinical sequelae of APS- associated arterial disease depend on the size and distribution of vascular beds involved (Table 23–1).
Table 23–1. Arterial Manifestations of Antiphospholipid Syndrome. |Favorite Table|Download (.pdf)
Table 23–1. Arterial Manifestations of Antiphospholipid Syndrome.
|Vascular Bed||Clinical Manifestation|
|Skin||Ulceration, gangrene, livedo reticularis|
|Cerebrovascular||Stroke, transient ischemic attack, seizure, encephalopathy, chorea, myelopathy, mononeuritis|
|Cardiac||Myocardial infarction, cardiomyopathy, valvular vegetations and abnormalities|
|Renal||Renal infarction, thrombotic microangiopathy|
|Pulmonary||Pulmonary emboli, microvascular thromboses, pulmonary hypertension, alveolar hemorrhage|
|Gastrointestinal||Mesenteric ischemia, splenic infarction|
|Ophthalmologic||Retinal artery thrombosis and ischemia|
Thromboses of medium-to-large peripheral arteries can lead to cutaneous ulceration and gangrene. Involvement of dermal capillaries can produce livedo reticularis (Plate 39), whose dusky, mottled appearance is due to a reactive hyperemia that occurs in normal skin adjacent to the regions of relative ischemia.
Cerebrovascular involvement can result in stroke, transient ischemic attack, dural sinus thrombosis, and an encephalopathy that can be difficult to distinguish from inflammatory or infectious cerebritis or cerebral vasculitis.
The cardiac manifestations of APS are protean. Thrombosis of epicardial vessels can cause myocardial infarction while subendothelial microangiopathy can lead to cardiomyopathy. APS is associated with Libman-Sacks endocarditis, which produces ...