In a group of 6 patients with lupus anticoagulant (LA) and antiphospholipid (aPL) antibodies detected by ELISA ovemight urine and blood were simultaneously collected. A significantly increased urinary excretion of the platelet-derived thromboxane (TX) metabolite 11-dehydro-TXB2 was found in this group, as compared to 12 healthy individuals. In contrast, a small but significant reduction of the vascular prostacyclin (PGI2) metabolite 2,3-dinor-6-keto-prostaglandin F1α was observed.
To further elucidate the effect of these antibodies on platelet activation we isolated the F(ab’)2 fragments from IgG of the 6 patients and 5 Controls, and we evaluated the effect of these fragments on the responses of isolated normal platelets to thrombin.
Patients’ F(ab’)2 increased platelet aggregation and serotonin release of platelets stimulated by low dose thrombin (0.01 U/ml). At threshold thrombin concentration (0.05 U/ml) an enhanced TXB2 production was also observed.
In summary, our results show, in addition to the altered TXA2/PGI2 balance observed in vivo, a direct stimulatory effect of aPL antibodies on platelet activation in vitro. This effect is related to recognition of phospholipid epitopes on platelets as shown by its neutralization upon preincubation with phospholipids. This phenomenon may be relevant for the thrombotic tendency of these patients.
References
1
Harris EN.
The antiphospholipid syndrome. An introduction. In: Phospholipid Binding Antibodies.
Harris EN,
Exner T,
Hughes GRV,
Asherson R.
(eds) Boca Raton, FL: CRC Press; 1991: 373-376
2
Pengo V,
Thiagarajan P,
Shapiro SS,
Heine MJ.
Immunological specificity and mechanism of action of IgG lupus anticoagulants. Blood 1987; 70: 69-76
3
Galli M,
Comfurius P,
Maassen C,
Hemker HC,
de Baets MH,
van Breda-Vriesman PJC,
Barbui T,
Zwaal RFA,
Bevers EM.
Anticar-diolipin antibodies (ACA) directed not to cardiolipin but to a plasma protein cofactor. Lancet 1990; 335: 1544-1547
4
McNeil HP,
Simpson RJ,
Chesterman CN,
Krilis SA.
Antiphos-pholipid antibodies are directed against a complex antigen that includes a lipid-binding inhibitor of coagulation: β2 glycoprotein I (apolipoprotein H). Proc Natl Acad Sci USA 1990; 80: 4120-4124
5
Bevers EM,
Galli M,
Barbui T,
Comfurius P,
Zwaal RFA.
Lupus anticoagulant IgG’s (LA) are not directed to phospholipids only, but to a complex of lipid-bound human prothrombin. Thromb Haemostas 1991; 66: 629-632
6
Oosting JD,
Derksen RHWM,
Entjes HTI,
Bouma BN,
de Groot PG.
Lupus anticoagulant activity is frequently dependent on the presence of β2 glycoprotein I. Thromb Haemostas 1992; 67: 499-502
7
Carreras LO,
Vermylen J.
“Lupus” anticoagulant and thrombosis. Possible role of inhibiton of prostacyclin formation. Thromb Haemostas 1982; 48: 38-40
10
Lechner K.
Lupus anticoagulant and thrombosis. In: Thrombosis and Haemostasis 1987.
Verstraete M,
Vermylen J,
Lijnen HR,
Arnout J.
(eds)
Leuven: International Society on Thrombosis and Haemostasis and Leuven University Press; 1987: 525-547
11
Carreras LO,
Defreyn G,
Machin SJ,
Vermylen J,
Deman R,
Spitz B,
Van Assche A.
Recurrent arterial thrombosis, repeated intra-uterine death and “lupus” anticoagulant. Detection of an immunoglobulin interfering with prostacyclin formation. Lancet 1981; 1: 244-246
12
Carreras LO,
Vermylen J,
Spitz BN,
Van Assche A.
“Lupus” anticoagulant and inhibition of prostacyclin formation in patients with repeated abortion, intra-uterine growth retardation and intra-uterine death. Br J Obstet Gynaecol 1981; 88: 890-894
13
de Castellarnau C,
Vita L,
Sancho MJ,
Borrel M,
Fontucuberta J,
Rutlant ML.
Lupus anticoagulant, recurrent abortion, and prosta-cyclin production by cultured smooth muscle cells. Lancet 1983; 2: 1137-1138
15
Watson KV,
Schorer AE.
Lupus anticoagulant inhibition of in vitro prostacyclin release is associated with a thrombosis – prone subset of patients. Am J Med 1991; 90: 47-53
16
Greaves M,
Lindsay N,
Malia RG,
Henderson F,
Hughes P.
Inhibition of thrombin-induced prostacyclin release by sera containing antiphospholipid antibodies is masked by products of platelet activation. Thromb Haemostas 1991; 65: 1257 (Abstr)
17
Petraiuolo W,
Bovill E,
Hoak J.
The lupus anticoagulant stimulates the release of prostacyclin from human endothelial cells. Thromb Res 1988; 50: 847-855
18
Walker TS,
Triplett DA,
Javed N,
Musgrave K.
Evaluation of lupus anticoagulants: antiphospholipid antibodies, endothelium associated immunoglobulin, endothelial prostacyclin secretion, and antigenic protein S levels. Thromb Res 1988; 51: 267-281
19
Cariou R,
Tobelem G,
Belucci S,
Soria J,
Soria C,
Maclouf J,
Caen J.
Inhibition of thrombomodulin-dependent protein C activation. Effect of lupus anticoagulant on antithrombogenic properties of endothelial cells. Thromb Haemostas 1988; 60 (01) 54-58
20
Rustin MHA,
Bull HA,
Dowd PM,
Isenberg DA,
Snaith MD,
Machin SJ.
Presence of the lupus anticoagulant in patients with systemic lupus erythematosus does not cause inhibition of prostacyclin production. Thromb Haemostas 1987; 58: 39 (Abstr)
21
Hasselaar P,
Derksen RHWM,
Blokzijl L,
de Groot PG.
Thrombosis associated with antiphospholipid antibodies cannot be explained by the effects on endothelial and platelet prostanoid synthesis. Thromb Haemostas 1988; 59: 80-85
22
Lellouche F,
Martinuzzo M,
Said P,
Maclouf J,
Carreras LO.
Imbalance of thromboxane/prostacyclin biosynthesis in patients with lupus anticoagulant. Blood 1991; 78: 2894-2899
23
Escolar G,
Font J,
Reverter JC,
Lopez-Soto A,
Garrido M,
Cervera R,
Ingelmo M,
Castillo R,
Ordinas A.
Plasma from systemic lupus erythematosus patients with antiphospholipid antibodies promotes platelet aggregation. Studies in a perfusion system. Arterioscler Thromb 1992; 12: 196-200
24
Out HJ,
de Groot PG,
van Vliet M,
de Gast GC,
Nieuwenhuis HK,
Derksen RHWM.
Antibodies to platelets in patients with antiphos-pholipid antibodies. Blood 1991; 77: 2655-2659
25
Forastiero RR,
Falcón CR,
Carreras LO.
Comparison of various screening and confirmatory tests for the detection of the lupus anticoagulant. Haemostasis 1990; 20: 208-214
27
Harris EN.
The Second International Anti-cardiolipin standardization Workshop/The Kingston Anti-phospholipid Antibody Study (KAPS) Group. Am J Clin Pathol 1990; 94: 476-484
28
Lellouche F,
Fradin A,
FitzGerald GA,
Maclouf J.
Enzyme immunoassay measurement of the urinary metabolites of thrombox-ane A2 and prostacyclin. Prostaglandins 1990; 40: 297-303
30
Lévy-Toledano S,
Maclouf J,
Bryon E,
Savarian E,
Hardisty RM,
Caen JP.
Human platelet activation in the absence of aggregation: A calcium-dependent phenomenon independent of the thromboxane formation. Blood 1982; 59: 1078-1085
31
Pradelles P,
Grassi J,
Maclouf J.
Enzyme immunoassay of eicosanoids using acetylcholinesterase as label: An alternative to radioimmuno-assay. Anal Chem 1985; 57: 1170-1173
32
Comp PC,
de Bault LE,
Esmon NL,
Esmon CT.
Human thrombomodulin is inhibited by IgG from two patients with non-specific anticoagulants. Blood 1983; 62: 1099 (Abstr)
33
Ruiz-Argüelles GJ,
Ruiz-Argüelles A,
Deleze M,
Alarcon-Segovia D.
Acquired protein C deficiency in a patient with primary antiphos-pholipid syndrome. Relationship to reactivity of anticardiolipin anti-body to thrombomodulin. J Rheumatol 1989; 16: 381-383
35
Hasselaar P,
Derksen RH,
Oosting JD,
Blokzijl L,
de Groot PG.
Synergistic effect of low doses of tumor necrosis factor and sera from patients with systemic lupus erythematosus on the expression of procoagulant activity by cultured endothelial cells. Thromb Haemo-stas 1989; 62: 654-660
37
Brandt JT.
The effect of lupus anticoagulants on expression of tissue factor activity by cultured endothelial cells. Thromb Haemostas 1991; 65: 673 (Abstr)
38
Chap H,
Zwaal RFA,
Van Deenen LLM.
Action of highly purified phospholipidases on blood platelets; evidence for an asymmetric distribution of phospholipids in the surface membrane. Biochim Biophys Acta 1977; 467: 146-164
39
Perret B,
Chap H,
Douste-Blazy L.
Asymmetric distribution of arachidonic acid in the plasma membrane of human platelets. Biochim Biophys Acta 1979; 556: 434-446
41
Comfurius P,
Brevers EM,
Zwaal RFA.
The involvement of cyto-skeleton in the regulation of transbilayer movement of phospholipids in human blood platelets. Biochim Biophys Acta 1985; 815: 143-148
42
Bevers EM,
Tilly RHJ,
Senden JMG,
Comfurius P,
Zwaal RFA.
Exposure of endogenous phosphatidylserine at the outer surface of stimulated platelets is reversed by restoration of amino-phospholipid translocase activity. Biochemistry 1989; 28: 2832-2839
44
Lellouche F,
Falcón C,
Carreras LO,
Maclouf J.
Selective inhibition of platelet-derived thromboxane A2 in patients with lupus anticoagu-lant using low doses aspirin as assessed by enzyme immunoassay. In: Advances in Prostaglandins, Thromboxane and Leukotriene Research, Vol 21.
Samuelsson B,
Ramwell PW,
Paoletti R,
Folco G,
Granström E.
(eds)
New York: Raven Press; 1990: 611-614
45
de Wolf F,
Carreras LO,
Moerman P,
Vermylen J,
Van Assche A,
Renaer M.
Decidual vasculopathy and extensive placental infarction in a patient with repeated thromboembolic accidents, recurrent fetal loss and a lupus anticoagulant. Am J Obstet Gynecol 1982; 142: 829-834
