antiphospholipid antibody syndrome
Also found in: Acronyms.
antiphospholipid antibody syndromeA thrombophilic disorder in which venous or arterial thrombosis, or both, may occur. The serologic markers are antiphospholipid antibodies (anticardiolipin antibodies), the lupus anticoagulant, or both; APAS is characterised by the presence of circulating antiphospholipid antibodies (APA), in particular against cardiolipin (ACA), which overlap with lupus anticoagulants.
APAs occur in patients with SLE and are associated with thromboembolic phenomena, often accompanied by habitual abortion, with mid-pregnancy foetal wastage due to thrombosis of placental vessels, DVT, recurrent MI (coronary thrombosis), pulmonary HTN, thrombocytopaenia, and occasionally also renal infarction. Other manifestations include livido reticularis, valvular heart disease, labile HTN, a positive Coombs test and recurrent digital gangrene, often in a background of SL; thrombosis may be related to the antibodies that inhibit prostacyclin (PGI2) production and interfere with the release of arachidonic acid from the cell membrane. The association of recurrent thromboses (cerebral), repeated spontaneous abortions and renal disease, often in ANA-negative SLE patients, has been termed the circulating lupus anticoagulant syndrome, which may be accompanied by repeated foetal wastage and IgM gammopathy.
Neurologic dysfunction may be accompanied by amaurosis fugax, CVAs, chorea, epilepsy, Guillain-Barré syndrome, migraines, multiple sclerosis-like disease, myelopathy and TIAs. APAs/ACAs may cause disease by acting on platelet membranes or vascular endothelia; APAs occur in TIAs and cardiac valve replacement.
High titres (> 7 standard deviations of IgG ACA) are reported as having 80% specificity for this condition. APAs cross-react with DNA, explaining the biological false positive serological test for syphilis commonly seen in SLE; increased APAs are found at autopsy in patients with thromboembolism.
Long-term anticoagulation with warfarin, with INR ≥ 3.
antiphospholipid antibody syndromeAntiphospholipid syndrome, circulating lupus anticoagulant syndrome Immunology The association of recurrent thromboses–cerebral, repeated spontaneous abortions and renal disease often in ANA-negative SLE Pts, which may be accompanied by repeated fetal wastage and IgM gammopathy; APA has been defined as a ' thrombophilic disorder in which venous or arterial thrombosis, or both, may occur. The serologic markers are antiphospholipid antibodies–anticardiolipin antibodies, the lupus anticoagulant, or both'; APAS is characterized by the presence of circulating antiphospholipid antibodies–APA, in particular against cardiolipin–ACA, here used interchangeably, which overlap with lupus anticoagulants. Cf Lupus anticoagulant.
an·ti·phos·pho·lip·id an·ti·bod·y syn·drome(APS, aPLS) (an'tē-fos-fō-lip'id an'ti-bod-ē sin'drōm)
A tendency for recurrent thrombosis together with recurrent abortion, thrombocytopenia, and neurologic disease, and elevated blood levels of antibodies against certain negatively charged phospholipids (e.g., cardiolipin, phosphatidylserine, and phosphatidylethanolamine).
antiphospholipid antibody syndrome(ant″i-fos″fō-lip′ĭd) [ anti-phospholipid],
A condition characterized by hypercoagulability associated with high blood levels of IgG antibodies against phospholipids. Many affected patients have a systemic autoimmune disease, e.g., systemic lupus erythematosus, but others present only with a history of frequent arterial and venous thrombi or pregnancy loss. Recent evidence suggests that antiphospholipid antibodies play a role in approx. 20% of strokes, esp. in patients who do not have common risk factors for stroke. Antiphospholipid antibodies include lupus anticoagulant and anticardiolipins; the presence of the latter causes these patients to test positive for syphilis.
Thromboses caused by the syndrome are treated and prevented with heparin, warfarin, corticosteroids, or, in some instances, immunosuppressant drugs such as cyclophosphamide.