Antifosfolipidic Syndrome
Question Received:
Response:
Can you tell me what is the antifosfolipidic syndrome, my wife has it? She has thrombocitopenia too. Her platelets are 100.
28th February 2001
During the late 1970s it was recognized that blood
clotting disorders can be linked with the appearance of certain antibodies in
the blood. Then in 1983 Hughes provided the first detailed description of the
antiphospholipid syndrome (described in Amengual et al, 1998). The main clinical
features of this syndrome are the repeated formation of inappropriate blood
clots (thromboses) in arteries and veins, miscarriages during pregnancy, and
commonly a reduction in the number of platelets in the blood. Platelets are also
known as thrombocytes because of their contribution to the process of blood
clotting, and if they are present in reduced numbers the condition is called
thrombocytopenia. Thrombocytopenia occurs in approximately 20 to 40% of the
patients with antiphospholipid syndrome (Galli, Finazzi, and Barbui, 1996).
Antiphospholipid syndrome may occur on its own or it may be associated with
other autoimmune diseases such as systemic lupus erythematosus (Gromnica-Ihle
and Schossler, 2000). The blood clots that occur in antiphospholipid syndrome
can affect vessels of all sizes (Khamashta and Hughes, 1995).
The antiphospholipid syndrome is associated with the presence of a family of
antibodies in the blood known as antiphospholipid antibodies. These are
autoantibodies, which means that the immune system has produced them against
normal constituents of the body rather than against infections or cancer cells.
Antiphospholipid syndrome occurs 2 to 5 times more frequently in women than in
men, and there may be a genetic susceptibility (family tendency) to this
condition in some people (Greco, Conti-Kelly, and Ijdo, 1997). The disease is
diagnosed by carrying out two tests, one for lupus anticoagulant antibodies and
the other for anticardiolipin antibodies. Higher levels of the antibody appear
to correlate with an increased risk of unwanted blood clots.
The antiphospholipid antibodies include lupus anticoagulant, anticardiolipin antibodies, antibodies against other phospholipids, and even antibodies that attach themselves to proteins in the blood plasma that have become linked with phospholipids. There is evidence that anticardiolipin antibodies form complexes with beta 2-glycoprotein I, a co-factor in the blood that normally inhibits the clotting cascade. These complexes then activate platelets, causing them to release substances which increase the risk of inappropriate clot formation (Krilis, Sheng, and Kandiah, 1996; Koike, 1997; Robbins et al, 1998; De Jong, Ziboh, and Robbins, 2000). The initial stimulus for the formation of antiphospholipid antibodies may be an abnormality in the process known as apoptosis during which cells in the body that are no longer needed close themselves down (Pittoni and Isenberg, 1998). It has been observed that cardiolipin molecules are expressed on the surface of cells at an early stage in the apoptotic shut-down sequence, and this may cause an over-reaction by the immune system (Sorice et al, 2000)
Antiphospholipid syndrome is generally treated over the long term with an anti-clotting drugs such as warfarin, heparin, or low-dose aspirin (Khamashta and Hughes, 1995). Severe, acute progression of antiphospholipid syndrome can be treated additionally with immunosuppressive agents (for example steroids), hydroxychloroquine sulphate, and plasmapheresis (Greco, Conti-Kelly, and Ijdo, 1997).
References
Amengual, O., Atsumi, T., Khamashta, M.A., and Hughes, G.R. (1998) Advances in antiphospholipid (Hughes') syndrome. Annals of The Academy of Medicine, Singapore, 27(1):61-6 (Jan).
De Jong, A., Ziboh, V., and Robbins, D. (2000) Antiphospholipid antibodies and platelets. Current Rheumatology Reports, 2(3), 238-245 (Jun).
Galli, M., Finazzi, G., and Barbui, T. (1996) Thrombocytopenia in the antiphospholipid syndrome: pathophysiology, clinical relevance and treatment. Annales de Medecine Interne, 147 Suppl 1, 24-27 (Sep).
Greco, T.P., Conti-Kelly, A.M., and Ijdo, J. (1997) Impact of the Antiphospholipid Syndrome: A Critical Coagulation Disorder in Women. Medscape Womens Health, 2(1), 7 (Jan).
Gromnica-Ihle, E., and Schossler, W. (2000) Antiphospholipid syndrome. International Archives of Allergy and Immunology, 123(1), 67-76 (Sep).
Khamashta, M.A., and Hughes, G.R. (1995) Antiphospholipid antibodies and antiphospholipid syndrome. Current Opinions in Rheumatology, 7(5), 389-394 (Sep).
Koike, T. (1997) Autoantibodies and thrombosis. [Article in Japanese] Hokkaido Igaku Zasshi. Hokkaido Journal of Medical Science, 72(5), 485-490 (Sep).
Krilis, S.A., Sheng, Y.H., and Kandiah, D.A. (1996) The role of beta 2-glycoprotein I in the antiphospholipid syndrome. Lupus, 5(2):150-152 (Apr).
Pittoni, V., and Isenberg, D. (1998) Apoptosis and antiphospholipid antibodies. Seminars in Arthritis and Rheumatism, 28(3), 163-178 (Dec).
Robbins, D.L., Leung, S., Miller-Blair, D.J., and Ziboh, V. (1998) Effect of anticardiolipin/beta2-glycoprotein I complexes on production of thromboxane A2 by platelets from patients with the antiphospholipid syndrome. Journal of Rheumatology, 25(1), 51-56 (Jan).
Sorice, M., Circella, A., Misasi, R., Pittoni, V., Garofalo, T., Cirelli, A., Pavan, A., Pontieri, G.M., and Valesini, G. (2000) Cardiolipin on the surface of apoptotic cells as a possible trigger for antiphospholipids antibodies. Clinical and Experimental Immunology, 122(2), 277-284 (Nov).