Cases differed from controls for factor V Leiden heterozygosity (16 of the 67 [24%] vs 13 [12%] of the 111, P = .038) and for lupus anticoagulant (9 [14%] of the 64 vs 4 [4%] of the 106, P = .019).
These included screening coagulations tests, tests for lupus anticoagulant (LA), IgG and IgM antibodies to anticardiolipin antibodies (ACA), beta2 glycoprotein 1 (beta2GP1) and annexin V. The genetic markers studied included protein C (PC), protein 5 (PS), antithrombin III (AT III), factor V Leiden (FVL), PT gene G20210A, MTHFR C677T, EPCR 23 bp insertion and PAI 4G/5G polymorphisms.
The 21 cases with VTE on TT differed from 110 patient controls with unprovoked VTE, not taking TT (VTE-no TT) for Factor V Leiden heterozygosity (FVL) (33 per cent vs 13 per cent, P=0.037), for high lipoprotein (a) (Lp(a)) (55 per cent vs 17 per cent, P=0.012), and for the lupus anticoagulant (33 per cent vs 4 per cent, P=0.003).
The single independent risk factors for thrombosis were mutation of factor V Leiden (P = 0.021), lupus anticoagulant antibodies (P = 0.028), and comorbidity (P = 0.000).
We analysed the association of venous and arterial thrombotic events with acquired (anticardiolipin antibodies (ACAs) and lupus anticoagulant (LA)) and inherited (antithrombin (AT), protein C (PC), protein S (PS) deficiencies, factor V Leiden and the prothrombin G20210A mutation), thrombophilic risk factors in 86 SLE patients and 89 healthy controls.
In conclusion, factor V Leiden and the prothrombin mutation contribute to the risk of VTE in patients with SLE, and potentiate this risk when one of these thrombophilic defects are combined with LA and/or ACAs.
We present a child on long-term treatment with levamisole, and heterozygous for factor V Leiden, who developed cutaneous necrosis associated with formation of p-ANCA and lupus anticoagulant.
The RVVT-based APC-resistance test provides better separation of factor V Leiden and normals in the various clinical settings, lupus anticoagulant in particular.
These include acquired antiphospholipid antibodies or the lupus anticoagulant as well as abnormalities of the inherited anticoagulant factors including protein C, protein S, antithrombin, and Factor V Leiden.
Compared to 111 VTE controls not taking TT (VTE-no TT), the 67 and 21 cases were more likely (<i>p</i> < 0.05 for all) to have Factor V Leiden (FVL) heterogeneity (24% and 33% vs. 12%), the lupus anticoagulant (14% and 33% vs. 4%), and high lipoprotein(a) (33% vs. 13%, <i>n</i> = 21).
Stepwise logistic regression analysis indicated that LAC (p = 0.005), male sex (p = 0.04), and hypertension (p = 0.03) were the strongest risk factors for developing thrombosis and that no additional risk was conferred by factor V Leiden (p = 0.13) and prothrombin gene mutation.
Rather, women who had APCR and /or factor V Leiden and lupus anticoagulant had significantly higher live birth rates (12.3% and 12.6%, respectively) in comparison to women who were tested negative (9.0% and 9.7%, respectively).
Inhibition of phospholipid-dependent coagulation by LAC antibodies rendered the APTT-based system less suitable than the phospholipid-rich RVVT-based one, and as nine of the 20 LAC-positive patients were on warfarin, we showed only the modified RVVT assay to be a reliable predictor of factor V Leiden in this patient group.