Phospholipid antibodies and resistance to activated protein C in women with thrombophilia.
Seventy-eight women with a history of thromboembolism were studied for cardiolipin antibodies (CLa), lupus anticoagulant activity (LA) and resistance to activated protein C (APC-resistance). Elevated CLa were found in 15 (19%) and LA in 15 women (19%), respectively. Twenty-six patients (33%) were APC-resistant, 17 of them had LA and/or CLa. No correlation was observed between the LA coefficient, CLa level and the extent of APC-resistance. The study shows the difference in the nature of phospholipid antibodies (PLa) and APC-resistance: cause-dependent for APC-resistance and time-dependent for the LA activity. APC-resistance was commoner in thrombosis triggered by endogenous (pregnancy, delivery) than by exogenous (oral contraceptives, surgery) factors (P < 0.05). The incidence of PLa was not connected to the cause of thrombosis. Time-dependent changes in the PLa spectrum manifested by a reduction of isolated LA frequency five years after thrombosis (P < 0.05). The response of APC seemed to show no variation with time passed after thrombosis. The co-existence of PLa and APC-resistance in 22% of thrombophilic women may stress the role of phospholipids in the blood coagulation process.
Bokarewa
M I
MI
Department of Laboratory Medicine, Karolinska Hospital, Stockholm, Sweden.
Blombäck
M
M
Bremme
K
K
D000328:Adult; D017152:Antibodies, Antiphospholipid / Q000097:blood*; D002308:Cardiolipins / Q000276:immunology; D004351:Drug Resistance; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007700:Kinetics; D016682:Lupus Coagulation Inhibitor / Q000097:blood; D008875:Middle Aged; D011247:Pregnancy; D011486:Protein C / Q000494:pharmacology*; D013927:Thrombosis / Q000276:immunology*
D017152:Antibodies, Antiphospholipid; D002308:Cardiolipins; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D016682:Lupus Coagulation Inhibitor; D011486:Protein C