Thrombosis risk in systemic lupus erythematosus: the role of thrombophilic risk factors.
OBJECTIVE
Thromboembolic episodes are frequent manifestations of systemic lupus erythematosus (SLE). Although the presence of anti-phospholipid antibodies (aPL) is known to contribute to thromboembolism (TE), the relative contribution of other TE risk factors is unknown. The aim of this study was to determine the prevalence of TE in a Caucasian SLE population, to identify the risk factors of highest importance, and to assess the clinical value of thrombophilia screening among SLE patients.


METHODS
Samples from 105 patients were analysed with a screen including aPL, activated protein C resistance, factor V Leiden (FVL) and prothrombin G20210A mutations; protein C, protein S and antithrombin activity; factor VIII (FVIII) and von Willebrand factor (vWF), and homocysteine (Hcy) levels.


RESULTS
The annual incidence of arterial and venous TE events in our SLE population was 5.4 and 12.4 per 1000, respectively. The highest risk of thrombosis was carried by the simultaneous presence of lupus anticoagulant (LA) and anti-cardiolipin (aCL) [relative risk (RR) = 4.03, 95% confidence interval (CI) 2.06-7.86] or anti-beta2-glycoprotein I antibodies (abeta2-GPI) (RR = 5.10, 95% CI 2.58-10.1). Positivity for the individual aPL tests all carried an elevated TE risk. The presence of other risk factors seemed to be of less importance.


CONCLUSIONS
In SLE patients, the presence of aPL is a more significant risk factor for the development of thrombosis than the known inherited deficiencies. Based on these data, routine screening for additional hereditary risk factors seems to be unwarranted.
Central Laboratory of Immunology, Semmelweis University Medical School, Budapest, Hungary. tina.sallai@freemail.hu
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Sallai
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Nagy
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Bodó
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Mohl
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Gergely
D000328:Adult; D017152:Antibodies, Antiphospholipid / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005165:Factor V / Q000235:genetics; D005169:Factor VIII / Q000032:analysis; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000150:complications*; D008875:Middle Aged; D009154:Mutation; D012307:Risk Factors; D019851:Thrombophilia / Q000209:etiology*; D013927:Thrombosis / Q000209:etiology*; D014841:von Willebrand Factor / Q000032:analysis
D017152:Antibodies, Antiphospholipid; C095381:factor V Leiden; D014841:von Willebrand Factor; D005165:Factor V; D005169:Factor VIII