Lupus and your body

What are antiphospholipid antibodies?

Dr. Michelle Petri is the Director of the Hopkins Lupus Cohort, a longitudinal study of morbidity and mortality in systemic lupus erythematosus, and Co-Director of the Hopkins Lupus Pregnancy Center.

See all of Michelle Petri, MD, MPH's answers.

Antiphospholipid antibodies cause blood vessels to become narrow and irregular (vasculopathy), which then causes blood clots to form (thrombosis). This can lead to complications such as stroke, heart attack, and miscarriage.

There are several kinds of antiphospholipid antibodies. The three most widely measured are:
• Lupus anticoagulant
• Anticardiolipin antibody
• Anti-β2 glycoprotein I
These antibodies are closely related, but are not the same. This means that a person can have one, and not the others. They are closely related since they are all directed against phospholipid molecules, a type of fat molecule that is part of the normal cell membrane.

Our thanks to Michelle Petri, MD, MPH, for this information.

Medically reviewed on July 25, 2013