Antiphospholipid syndrome

Antiphospholipid syndrome (APS) is an autoimmune disorder. It occurs when your body's immune system makes antibodies that attack phospholipids (a type of fat found in living cells). The exact reason for this is not known. While APS is not passed through families in a predictable pattern, genetics are thought to play a role. A widely accepted explanation for APS is that it is caused by a combination of gene mutations (making one more susceptible to APS) and an environmental exposure (such as a viral infection).

Research has found a few gene changes that occur in people with APS, however the contribution of these genetic changes to the development of the condition is unclear. Little is known about specific environmental triggers. Known risk factors include female sex and having other autoimmune-type disorders (such as Lupus).

Some people have APS antibodies, but have no signs or symptoms. These people are also at an increased risk for APS. In these cases, APS symptoms (for example blood clots) can be triggered by smoking, prolonged bed rest, pregnancy and the postpartum period, birth control pills, hormone therapy, cancer, and kidney disease.