NeurometPlus

Incidence

Less than 200,000 cases per year in the US. The exact prevalence of antiphospholipid syndrome is unknown. This condition is thought to be fairly common, and may be responsible for up to one percent of all thromboses. It is estimated that 20 percent of individuals younger than age 50 who have a stroke have antiphospholipid syndrome. Ten to 15 percent of people with systemic lupus erythematosus have antiphospholipid syndrome. Similarly, 10 to 15 percent of women with recurrent miscarriages likely have this condition. Approximately 70 percent of individuals diagnosed with antiphospholipid syndrome are female. MGJM

Clinical Characteristics

Antiphospholipid syndrome (APS) is an acquired autoimmune disorder that manifests clinically as recurrent venous or arterial thrombosis and/or fetal loss. Characteristic laboratory abnormalities in APS include persistently elevated levels of antibodies directed against membrane anionic phospholipids (ie, anticardiolipin [aCL] antibody, antiphosphatidylserine) or their associated plasma proteins, predominantly beta-2 glycoprotein I (apolipoprotein H); or evidence of a circulating anticoagulant. Affects women five times more commonly than men, it is typically diagnosed between the ages of 30 and 40.
Multiple terms for APS exist. Unfortunately, some synonyms can be confusing. Lupus anticoagulant (LA) syndrome, for example, is misleading—first, because patients with APS may not necessarily have systemic lupus erythematosus (SLE), and second, because although LAs do have an anticoagulant effect in vitro, LA syndrome manifests clinically with thrombotic rather than hemorrhagic complications. In an attempt to avoid further confusion, APS is currently the preferred term for the clinical syndrome (as described below). Signs and symptoms vary, but may include blood clots, miscarriage, rash, chronic headaches, dementia, and seizures.
Some patients with APS have no evidence of any definable associated disease, while, in other patients, APS occurs in association with SLE or another rheumatic or autoimmune disorder.
Other common findings, although not part of the APS classification criteria, are low platelet count, heart valve disease, and livedo reticularis. There are also associations between antiphospholipid antibodies and headaches, migraines, and oscillopsia.Some studies have shown the presence of antiphospholipid antibodies in the blood and spinal fluid of patients with psychological symptoms.

Precipitants

It\\\'s possible to have the antibodies associated with antiphospholipid syndrome without developing signs or symptoms. However, having these antibodies increases your risk of developing blood clots, particularly if you:

Become pregnant
Are immobile for a time, such as being on bed rest or sitting during a long flight
Have surgery
Smoke cigarettes
Take oral contraceptives or estrogen therapy for menopause
Have high cholesterol and triglycerides levels

Provocation Tests

none

Diagnostic Procedures

Anti-cardiolipin IgG and/or IgM measured by standardized, non-cofactor dependent ELISA on 2 or more occasions, not less than 12 weeks apart; medium or high titre (i.e., > 40 GPL or MPL, or > the 99th percentile) and/or Anti-β2 glycoprotein I IgG and/or IgM measured by standardized ELISA on 2 or more occasions, not less than 12 weeks apart; medium or high titre (> the 99th percentile) and/or Lupus anticoagulant detected on 2 occasions not less than 12 weeks apart according to the guidelines of the International Society of Thrombosis and Hemostasis.

Antiphospholipid syndrome is tested for in the laboratory using both liquid phase coagulation assays (lupus anticoagulant) and solid phase ELISA assays (anti-cardiolipin antibodies). Genetic thrombophilia is part of the differential diagnosis of APS and can coexist in some APS patients. Presence of genetic thrombophilia may determine the need for anticoagulation therapy. Thus genetic thrombophilia screening can consist of: Further studies for factor V Leiden variant and the prothrombin G20210A mutation, factor VIII levels, MTHFR mutation. Levels of protein C, free and total protein S, factor VIII, antithrombin, plasminogen, tissue plasminogen activator (TPA) and plasminogen activator inhibitor-1 (PAI-1). Certain genetic variations (polymorphisms) in a few genes have been found in people with antiphospholipid syndrome and may predispose individuals to produce the specific antibodies known to contribute to the formation of thromboses. However, the contribution of these genetic changes to the development of the condition is unclear.