Antiphospholipid antibodies or not? The role of beta 2 glycoprotein 1 in autoantibody-mediated pregnancy loss.
Antiphospholipid antibodies are a family of autoantibodies including lupus anticoagulant and anticardiolipin antibodies that appear to react with negatively charged phospholipids. These antibodies induce thrombosis and pregnancy complications including recurrent stillbirth, recurrent miscarriage, pre-eclampsia and intra-uterine growth retardation. Recent evidence indicates that antiphospholipid antibodies do not bind directly to phospholipid but rather to phospholipid-binding proteins or to a combination of phospholipid and phospholipid-binding proteins. This opens the possibility that antiphospholipid antibodies may be pathogenic by disrupting the function of phospholipid-binding proteins rather than membrane phospholipid. The antigenic role of one phospholipid-binding protein, beta 2 glycoprotein, has been studied in the greatest detail and is reviewed. Despite being highly conserved and expressed at high levels, the physiological function of beta 2 glycoprotein 1 remains unknown. However, a number of putative roles have been proposed which allow speculation as to the mechanism by which antiphospholipid antibodies may disrupt haemostasis and pregnancy.
Chamley
L W
LW
Department of Obstetrics and Gynaecology, University of Auckland, National Women's Hospital, New Zealand. l.chamley@auckland.ac.nz
D000818:Animals; D017152:Antibodies, Antiphospholipid / Q000266:history / Q000502:physiology*; D004195:Disease Models, Animal; D005260:Female; D006023:Glycoproteins / Q000502:physiology*; D049673:History, 20th Century; D006801:Humans; D051379:Mice; D010743:Phospholipids / Q000276:immunology / Q000378:metabolism; D010920:Placenta / Q000276:immunology / Q000502:physiology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000209:etiology* / Q000276:immunology* / Q000503:physiopathology; D009626:Terminology as Topic; D053482:beta 2-Glycoprotein I
D017152:Antibodies, Antiphospholipid; D006023:Glycoproteins; D010743:Phospholipids; D053482:beta 2-Glycoprotein I