[Factor V Leiden and prothrombin G20210A among Chilean patients with venous and arterial thrombosis]. / Factor V Leiden y mutación de la protrombina G20210A en pacientes con trombosis venosa y arterial.

BACKGROUND: Factor V Leiden and G20210A mutation of prothrombin gene are two important genetic polymorphisms associated with an increased risk for thrombosis. AIM: To establish the prevalence of factor V Leiden and prothrombin G20210A mutation in the Chilean population and their association to venous and arterial thromboembolism. MATERIAL AND METHODS: A case-control study was conducted where 149 patients with thrombosis (87 with arterial and 62 with venous thrombosis) confirmed by CAT-scan, electrocardiogram and cardiac enzymes or Doppler depending on the case, and 160 healthy blood donors were genetically analyzed for the presence of both polymorphisms. RESULTS: Factor V Leiden mutation was found in 5.4% of patients and in 1.3% of healthy controls (p=0.04). Heterozygosity for G20210A prothrombin mutation was found in 5.4% of patients and in 2.5% of the control group (p=NS). When arterial and venous thrombosis were considered as separate entities, 4.6% of patients with arterial thrombosis and 6.5% with venous thrombosis presented factor V Leiden (p=NS). Likewise, 8.1% of patients with venous thrombosis and 3.5% of patients with arterial thrombosis had G20210A prothrombin mutation (p=NS). CONCLUSIONS: In non selected consecutive Chilean patients with arterial and venous thrombosis the frequency of factor V Leiden and prothrombin G20210A is less than we could expect from their prevalence in the general population.

Prevalence and isotype distribution of antiphospholipid antibodies in unselected Chilean patients with venous and arterial thrombosis.

Antiphospholipid antibodies (aPL) are a heterogeneous family of antibodies associated with thrombotic events and other complications. The objective of this study was to investigate the prevalence of aPL in a group of Chilean patients with thrombosis. Two hundred and twenty-six patients with venous and arterial thrombosis and 95 healthy controls were studied. Anticardiolipin (aCL), anti-beta(2 )glycoprotein I (anti-beta(2)GPI), and antiprothrombin (aPT) antibodies were determined. Eighty-eight out of 226 (38.9%) patients with thrombosis had some type of aPL. Fifty-seven patients (25.2%) were positive for aCL, 31 (13.7%) for aPT, and 14 (6.2%) for anti-beta(2)GPI antibodies. Twelve patients (5.3%) were positive for more than one aPL. IgG, IgM and IgA isotypes were observed in aCL, anti-beta(2)GPI, and aPT antibodies. Twenty-six out of 92 (28.3%) patients with venous thrombosis and 31/134 (23.1%) patients with arterial thrombosis were positive for aCL antibodies. With regard to the control group (4/95=4.2%), the odd ratios (OR) were 5.2 (1.3-19.8; p0.01) and 5.7 (1.6-22.3; p0.01), respectively. Additionally, we observed statistically significant OR with aPT and anti-beta(2)GPI antibodies; in the first, with venous and arterial thrombosis, and in the second, only with arterial thrombosis. Our results show a significant prevalence of aPL, predominantly aCL and aPT antibodies, in patients with thrombosis. Additionally, aCL and aPT antibodies appear to be a risk factor for venous and arterial thrombosis, and anti-beta(2)GPI antibodies appear to be a risk factor for arterial thrombosis.

Antiphospholipid antibodies in Chilean patients with systemic lupus erythematosus.

Antiphospholipid antibodies (aPLs) are a heterogeneous family of antibodies found in autoimmune disorders, infectious diseases, and other situations. The presence of different aPLs has been associated with various clinical manifestations of the antiphospholipid syndrome (APS). The objective of this study was to investigate the prevalence of aPLs in a group of 90 Chilean patients with systemic lupus erytematosus (SLE) and 90 healthy controls. We measured anticardiolipin antibodies (aCLs), antiphosphatidylserine antibodies (aPSs), anti-beta(2) glycoprotein I antibodies (anti-beta(2)GPIs), and antiprothrombin antibodies (aPTs) with an enzyme-linked immunosorbent technique using "in-house" assays. Fifty-four of 90 SLE patients (60.0%) had some type of aPL. Forty of 90 (44.4%) were positive for aCLs, 9 of 61 (14.8%) had aPSs, 21 of 90 (23.3%) had anti-beta(2)GPIs, and 18 of 90 (20.0%) had aPTs. In the control group, prevalences were as follows: aCLs, 3.3%; aPSs, 1.1%; anti-beta(2)GPIs, 1.1%; aPTs, 2.2%. In most cases, values were in the low-positive range. Of all aPL detected, 29.5% was of the IgG isotype, 37.5% IgM, and 33.0% IgA. We observed a correlation between aCLs and aPSs and of these antibodies with anti-beta(2)GPIs and aPTs but not between anti-beta(2)GPIs and aPTs. Our results show a high prevalence of aPLs in SLE patients. An association between different specificities and isotypes of aPLs was also observed.