A new variant of interaction between phospholipid antibodies and the protein C system.
The influence of 38 IgG fractions with either cardiolipin antibodies only (CLa) or both CLa and lupus anticoagulant activity (LA) on the response to activated protein C (APC) and on the snake venom activation of protein C were investigated. Five of eight IgG fractions with LA activity showed a tendency to reduce the effect of APC in the aPTT method and to simulate the APC-resistance phenomenon. This effect was not observed in IgG fractions without LA activity. The addition of IgG fractions did not decrease enzymatic activation of protein C in normal plasma. No correlation was found between sample protein C activity and CLa level or the extent of clotting time prolongation. These observations suggested that acquired resistance to APC in the presence of some types of phospholipid antibodies may be a cause of thrombophilia in such patients.
Bokarewa
M I
MI
Department of Laboratory Medicine and Blood Coagulation, Karolinska Hospital, Stockholm, Sweden.
Blombäck
M
M
Egberg
N
N
Rosén
S
S
D000328:Adult; D000368:Aged; D017153:Antibodies, Anticardiolipin / Q000494:pharmacology; D017152:Antibodies, Antiphospholipid / Q000494:pharmacology*; D002850:Chromatography, Gel; D004789:Enzyme Activation; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000494:pharmacology; D016682:Lupus Coagulation Inhibitor / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D011486:Protein C / Q000378:metabolism*
D017153:Antibodies, Anticardiolipin; D017152:Antibodies, Antiphospholipid; D007074:Immunoglobulin G; D016682:Lupus Coagulation Inhibitor; D011486:Protein C