Anti-beta 2-glycoprotein I antibodies: a marker of antiphospholipid syndrome?

Abstract

Anticardiolipin (aCL) and anti-beta2-glycoprotein I(antiβ2GPI) antibodies have been shown in animal models as not cross-reacting antibody populations. This observation prompted us to prove if anti-β2GPI exist in human sera by using a reliable method and then to investigate if these are independent from aCl antibodies. We have developed a new ELISA for the detection of anti-β2GPI antibodies employing the coating of the protein in carbonate buffer to irradiated microtitre plates and the filtration of serum samples, that makes irrelevant the binding to the uncoated wells. IgG F(ab)₂ fragments from IgG positive sera were shown bind β2GPI, providing that the binding was a specific antibody binding, mediated by the antigen binding site of the antibody molecule; moreover the antibodies were not able to differentiate native and delipidated β2GPI coated plates, making a possible role of a phospholipid contaminant unlikely. On the other hand, the phosphorus content of native as well as delipitated β2GPI was undetectable. IgG, but not IgM, anti-β2GPI antibodies were classically inhibited by the addition of soluble β2GPI, while cardiolipin liposomes appear to modify the reaction in a completely different way, possibly by the described interaction between cardiolipin and β2GPI. The application of the new ELISA to the study of patients has shown that: (1) the presence of anti-β2GPI is statistically associated with the presence of aCL antibodies (P < 0.0001), (2) anti-β2GPI antibodies are related to the classical features of antiphospholipid syndrome (thrombosis: P < 0.001; fetal loss: P < 0.001) while, in this series of patients, aCl antibodies are not (thrombosis: P < 0.126; fetal loss: P < 0.061).

Keywords

Anti-beta2-glycoprotein I Antiphospholipid antibodies anticardiolipin antibodies antiphospholipid syndrome

Get full access to this article

View all access options for this article.

References

Wassermann A. , Neisser A. , Bruck C. Eine serodiagnostische Reaction bei Syphili . Deutsch Med Wochenschr 1906; 19: 619-25.

Laurell AB , Nilsson IM Hypergamma-globulinemia, circulating anticoagulant and biologic false positive Wassermann reaction: a study of 2 cases. J Lab Clin Med 1957; 49: 694-707.

Harris EN , Gharavi AE , Boey ML et al. Anticardiolipin antibodies: detection by radioimmunoassay and association with thrombosis in systemic lupus erythematosus. Lancet 1983; ii: 1211-14.

Hughes Grv. The antiphospholipid syndrome: ten years on. Lancet 1993; 342: 341-4.

Pangborn MC A new serologically active phospholipid from beef heart. Proc Soc Exp Biol Med 1941; 48: 484-6.

Harris EN , Gharavi AE , Wasley GD , Hughes Grv. Use of an enzyme-linked immunosorbent assay and of inhibition studies to distinguish between antibodies to cardiolipin from patients with syphilis or autoimmune disorders. J Infect Dis 1988; 157: 23-31.

Galli M. , Comfurius P. , Maassen C. et al. Anticardiolipin antibodies directed not to cardiolipin but to a plasma protein cofactor. Lancet 1990; 335: 1544-7.

McNeil HP , Simpson RJ , Chesterman CN , Krilis SA Antiphospholipid 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; 87: 4120-4.

Schousboe J. β2-glycoprotein I: a plasma inhibitor of contact activation of the intrinsic blood coagulation pathway. Blood 1985; 66: 1085-9.

10.

Gharavi AE , S ammaritano LR, Wen J, Elkon KB. Induction of antiphospholipid autoantibodies by immunization with β2 glycoprotein I (apilipoprotein H). J Clin Invest 1992; 90: 1105-9.

11.

Pierangeli SS , Harris EN Induction of phospholipid-binding antibodies in mice and rabbits by immunization with human β2 glycoprotein I or anticardiolipin antibodies alone. Clin Exp Immunol 1993; 93: 269-72.

12.

Blank M. , Faden D. , Tincani A. et al. Immunization with anticardiolipin cofactor (beta-2-glycoprotein I) induces experimental antiphospholipid syndrome in naive mice. J Autoimmun 1994; 7 (in press).

13.

Arvieux J. , Roussel B. , Jacob MC et al. Measurement of antiphospholipid antibodies by ELISA using β2-glycoprotein I as antigen. J Immunol Methods 1991; 143: 223-9.

14.

Viard JP , Amoura Z. , Bach JF Association of anti-β2 glycoprotein I antibodies with lupus-type circulating anticoagulant and thrombosis in systemic lupus erythematosus. Am J Med 1992; 93: 181-6.

15.

Cabral AR , Rodriguez M. , Cabiedes J. , Alarcon Segovia D. Antibodies to β2-glycoprotein I associate with antiphospholipid syndrome whether primary (PAPS) or secondary to systemic lupus erythematosus. Arthritis Rheum 1993; 6 (Suppl.): S242.

16.

Gharavi AE , Harris EN , Sammaritano LR et al. Do patients with antiphospholipid syndrome have autoantibodies to beta(2) glycoprotein-1? J Lab Clin Med 1993; 122: 426-31.

17.

Tan EM , Cohen AS , Fries JF et al. The 1982 revised criteria for classification of systemic lupus erythematosus. Arthritis Rheum 1982; 25: 1271-7.

18.

La Rosa L. , Meroni PL , Tincani A. et al. Beta 2 glycoprotein I and placental anticoagulant protein 1 in placentae from patients with antiphospholipid syndrome. J Rheumatol 1994; 21 (in press).

19.

McConahey PJ , Dixon FJ A method of trace iodination of proteins for immunological studies. Int Arch Allergy Appl Immunol 1966; 29: 185-9.

20.

Hardy RR Purification and characterization of monoclonal antibodies. In: Handbook of Experimental Immunology, 4th edn. Weir DM (ed.). Oxford: Blackwell Scientific, 1986, 13: 1.

21.

Bartlett GR Phosphorus assay in column chromatography. J Biol Chem 1959; 234: 466-8.

22.

Harris EN The Second International Anti-Cardiolipin Standardization Workshop/The Kingston Anti-Phospholipid Antibody Study (KAPS) Group. Am J Clin Pathol 1990; 94: 476-84.

23.

Exner T. , Rickard KA , Kronenberg H. A sensitive test demonstrating lupus anticoagulant and its behavioural patterns . Br J Haematol 1978; 40: 143-51.

24.

Stanworth DR , T urner NW Immunochemical analysis of human and rabbit immunoglobulins and their subunits . In: Handbook of Experimental Immunology, 4th edn. Weir DM (ed.). Oxford: Blackwell Scientific, 1986 ; 12: 1.

25.

Pierangeli SS , Harris EN , Davis SA et al. β2-glycoprotein I (β2GPI) enhances cardiolipin binding activity but is not the antigen for antiphospholipid antibodies . Br J Haematol 1992; 82: 565-70.

26.

Matsuura E. , Igarashi Y. , Yasuda T. et al. Anticardiolipin antibodies recognize β2-glycoprotein I structure altered by interacting with an oxygen modified solid phase surface . J Exp Med 1994; 179: 457-62.

27.

Roubey Ras , Eisenberg RA , Winfield JB Autoantibodies to β-glycoprotein I: the role of antibody affinity and antigen density. Lupus 1994; 3: 314 (abstract no. 5).

28.

Alarcon-Segovia D. , Cabral AR

Antiphospholipid antibodies. Where do they come from? Where do they go?

J Rheumatol 1994 ; 21: 982-9.

29.

Wurm H. β2-glycoprotein I (apolipoprotein H) interaction with phospholipid vesicles . Int J Biochem 1984; 16: 511-15.

30.

Waghenknech DR , McIntyre JA. Changes in β2-glycoprotein I antigenicity induced by phospholipid binding. Thromb Haemostas 1993; 63: 361-5.

31.

Matsuura E. , Igarashi Y. , Fujimoto M. et al. Anticardiolipin cofactor(s) and differential diagnosis of autoimmune diseases. Lancet 1990 ; 336: 177-8.

32.

Hunt JE , McNeil HP , Morgan GJ et al. A phospholipid-β2-glycoprotein I complex is an antigen for anticardiolipin antibodies occurring in autoimmune disease but not with infection . Lupus 1992; 1: 75-81.

33.

Hojnik M. , Gilburd B. , Ziporen L. et al. Anticardiolipin antibodies in infections are heterogenous in their dependency on β2-glycoprotein I: analysis of anticardiolipin antibodies in Leprosy. Lupus 1994; 3 (in press).