Effects of human monoclonal anticardiolipin antibodies on platelet function and on tissue factor expression on monocytes.
OBJECTIVE
To investigate the effect of human monoclonal anticardiolipin antibodies (aCL) on platelet interaction with the subendothelium under flow conditions and on tissue factor (TF) expression on normal monocytes.


METHODS
Three monoclonal IgM aCL (TM1B3, GR1D5, and EY2C9) and 2 affinity-purified IgM aCL were studied. Immunoglobulins were added to normal blood and perfused through chambers containing denuded vascular segments. Platelet interactions were morphometrically evaluated by determining the percentage of total surface covered by platelets (PCS) or by large aggregates of thrombi platelets (TP). Expression of TF on monocytes was measured after immunoglobulin incubation with normal mononuclear cells.


RESULTS
Significant increases in the total PCS and expression of TF were observed using all aCL. Increased levels of TP were induced by all aCL except EY2C9 (obtained from a patient without thrombosis). Previous incubations of these aCL with subendothelial surfaces did not increase platelet interaction.


CONCLUSIONS
The effects of aCL on platelet function may help to explain the pathophysiology of thrombosis in the antiphospholipid syndrome.
Hospital Clínic, Barcelona, Spain.
J C
JC
Reverter
D
D
Tàssies
J
J
Font
M A
MA
Khamashta
K
K
Ichikawa
R
R
Cervera
G
G
Escolar
G R
GR
Hughes
M
M
Ingelmo
A
A
Ordinas
D000328:Adult; D017153:Antibodies, Anticardiolipin / Q000494:pharmacology*; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D001779:Blood Coagulation Factors / Q000378:metabolism; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D002470:Cell Survival / Q000502:physiology; D004730:Endothelium, Vascular / Q000502:physiology; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000378:metabolism; D008875:Middle Aged; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism*; D013925:Thromboplastin / Q000378:metabolism*
D017153:Antibodies, Anticardiolipin; D000911:Antibodies, Monoclonal; D001779:Blood Coagulation Factors; D007075:Immunoglobulin M; C045071:leukocyte procoagulant activity; D013925:Thromboplastin