Activation of endothelial cells by antiphospholipid antibodies--a possible mechanism triggering thrombosis in patients with antiphospholipid syndrome.
Antiphospholipid syndrome (APS) is an antibody-mediated hypercoagulable state characterized by recurrent venous and arterial thromboembolic events. The presence of serum antibodies are collectively termed as antiphospholipid antibodies (aPL) and is the hallmark of the disease. Interest in the pathogenesis has mostly been focused on the blood coagulation factor. However, endothelial cells might play an important role. When stimulated, cell membrane would flip to expose negatively charged phospholipids and activation markers such as adhesive molecules may appear. We consider that these changes may play an important role in the initiation of the thrombotic process when endothelial cells encounter a PL. In this study, we incubated human umbilical vein endothelial cells (HUVECs) with IgG isolated from patients with APS and found that the HUVECs were activated by the expression of negatively charged phospholipids, as shown by high annexin V binding and negative propidium iodide staining and by an increase in the level of intracellular cell adhesion molecule-1 on the cell surface. The above findings indicate that endothelial cells can be activated on exposure to aPL and trigger the thrombotic event.
Chen
Pei-Pei
PP
Division of Rheumatology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
Lin
Yu-Chih
YC
Wu
Kun-Che
KC
Yen
Jeng-Hsien
JH
Ou
Tsan-Teng
TT
Wu
Chen-Ching
CC
Liu
Hong-Wen
HW
Tsai
Wen-Chan
WC
D000328:Adult; D017152:Antibodies, Antiphospholipid / Q000633:toxicity*; D016736:Antiphospholipid Syndrome / Q000150:complications*; D042783:Endothelial Cells / Q000502:physiology*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000502:physiology; D018799:Intercellular Adhesion Molecule-1 / Q000032:analysis; D008563:Membrane Lipids / Q000032:analysis; D010743:Phospholipids / Q000032:analysis; D013927:Thrombosis / Q000209:etiology*
D017152:Antibodies, Antiphospholipid; D007074:Immunoglobulin G; D008563:Membrane Lipids; D010743:Phospholipids; D018799:Intercellular Adhesion Molecule-1