What causes the antiphospholipid syndrome?

What causes the antiphospholipid syndrome?

The cause of antiphospholipid syndrome is not completely known. Antiphospholipid antibodies reduce the levels of annexin V, a protein that binds phospholipids and has potent clot-blocking (anticoagulant) activity. The reduction of annexin V levels is thought to be a possible mechanism underlying the increased tendency of blood to clot and the propensity to pregnancy loss characteristic of the antiphospholipid syndrome.

Antiphospholipid antibodies, such as anticardiolipin, have also been associated with decreased levels of prostacyclin, a chemical that prevents the clumping together of normal blood clotting elements called platelets.

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