Causes of portal venous thrombosis in cirrhotic patients: the role of genetic and acquired factors.

OBJECTIVE AND METHODS: We compared frequencies of three common prothrombotic mutations (factor V Leiden, the G20210A mutation of the prothrombin gene, and homozygosity for C677T methylenetetrahydrofolate reductase) in 219 cirrhotic patients, 43 with and 176 without portal vein thrombosis (PVT). The following variables were related to PVT: prothrombin levels, platelet count, Child-Pugh classification, previous abdominal surgery, number of decompensation events, size of varices, red markers on varices, and sclerotherapy. All patients were followed up for a mean period of 18 months (range 10-30). RESULTS: Prothrombotic mutations were detected in 64 of the 219 cirrhotic patients (29.2%), at equal frequency in patients with or without PVT. At univariate analysis, PVT was associated with Child-Pugh classes B and C, signs of liver decompensation, large varices with red markings, sclerotherapy, and abdominal surgery. At multivariate analysis, PVT was associated with sclerotherapy [odds ratio (OR) 4.9, 95% confidence interval (CI) 2.2-11] and previous surgery (OR 2.8, 95% CI 1.2-6.3). The combination of the two acquired factors increased the risk of PVT, whereas the combination of local with genetic defects did not. Only a single patient with genetic thrombophilia and without PVT at inclusion developed the complication during follow-up, concomitantly with the development of hepatocellular carcinoma. CONCLUSION: In cirrhotic patients prothrombotic mutations by themselves are not causative of PVT. Sclerotherapy and previous abdominal surgery favour the development of two-thirds of cases of PVT; in the remaining cases the pathogenesis remains elusive.

Is steam sterilization really making any difference in dialysis-induced cytokine release?

Ethylene oxide (ETO) is presently the most commonly used sterilization method for medical devices. Although alternative sterilization modes such as steam sterilization have been suggested, the effect of steam on dialysis-induced cytokine release is unknown. We enrolled 9 patients on chronic hemodialysis and evaluated at different intervals IL-1beta production while treated with ETO (NC 1785-Bellco) and steam sterilized NC 1785S-Bellco) Synthetically Modified Cellulose (SMC). A basal test during treatment with NC 1785 was performed (A); the same test was set up 4 weeks after treatment with NC 1785S (B) and, lastly, 4 weeks after returning to NC 1785 (C). Peripheral blood mononuclear cells (PBMC) were purified before and after the dialysis session, were isolated on a Ficoll/Hypaque gradient and incubated for 24 h. Spontaneous IL-1beta release was evaluated in the supernatant and in the lysate. In A, IL-1beta levels were (in pg/ml/10(6) cells, in supematant and lysate, respectively): 5.8 +/- 4.8 and 7.6+/-5.2 in pre-HD and 4.68 +/- 3.6 and 9.7 +/- 6.65 in post-HD. These levels showed a clear reduction in B: 2.5 +/- 2.2 and 4.4 +/- 3.1 in pre-HD, and 4.35+/- 6.6 and 7.52 +/- 7.22 in post-HD. In the C test, 4 weeks after the return to the ETO membrane, IL-1beta levels remained unchanged: 2.9 +/- 1.8 and 4.5 +/- 3.1 in pre-HD; and 2.6 +/- 3 and 5.7 +/- 6.6 in post-HD. Statistical analysis showed significant changes in the pre-HD levels both in supematant (p < 0.04) and in lysate (p < 0.04). Steam sterilization of SMC induced a lower spontaneous IL-1beta release, but this effect was not statistically significant due to the large inter-individual variation. Hence, contrary to claims of better biocompatibility, steam sterilization does not result in a reduced production of pro-inflammatory IL-1beta.

Occurrence of factor V Leiden mutation (Arg506Gln) and anticardiolipin antibodies in migraine patients.

The occurrences of factor V Leiden mutation (Arg506Gln) and antiphospholipid antibodies (APA) in migraine patients have been reported, but the findings are controversial. We investigated the presence of factor V Leiden and the serum level of anticardiolipin antibodies (aCL) in a consecutive series of 70 migraine patients (47 women; mean age, 34.1 years). Of these, 40 patients had migraine with aura. A matched sample of 70 healthy people was considered as the control group. Heterozygous genotype for factor V Leiden mutation was detected in 4 (5.7%) migraine patients (of which 2 had migraine with aura) and in 2 (2.8%) subjects of the control group. Although proportionally more migraine patients harbored the factor V Leiden mutation, this difference was not statistically significant, perhaps due to the small number of patients involved. We found normal serum levels of aCL in all migraine patients. Further studies and a long-term follow-up are warranted to determine the significance of this genetic abnormality in migraine.

Comparative prevalence of antiphospholipid antibodies and thrombophilic genotypes in consecutive patients with venous thrombosis.

The prevalence of antiphospholipid antibodies (aPL) and thrombophilic genotypes was compared and their reciprocal interactions assessed in consecutive patients with venous thrombosis (n = 101; 58 male, 43 female; mean age, 56 +/- 16 years) and in blood donors (n = 121; 55 male, 46 female; mean age, 43 +/- 12 years). Multiple aPL were detected by enzyme-linked immunosorbent assay (ELISA) and factor V Leiden (FVL), methylenetetrahydrofolate reductase (MTHFR) C677 <-- T and prothrombin (PT) G20210 <-- A by polymerase chain reaction. A pro-thrombotic state, including aPL, was found in 81% (82/101) of patients and 23% (29/121) of controls (P < 0.0001, odds ratio = 13.69, 95% confidence interval = 7.14-26.25). The prevalence of total aPL-positives was lower than MTHRF+/+ (homozygous state), FVL and PT G20210 <-- A (P < 0.0001) in the control group, but in line with the prevalence of total thrombophilic genotypes in the patient group: MTHFR+/+, 29%; FVL, 19%; PT, 14%; aPL, 20%. Having variously combined aPL and thrombophilic genotypes, only aPL remained as the most common pro-thrombotic factor in the patient group (P = 0.003). In patients without circumstantial factors for thrombosis, carriers of MTHFR+/+ + aPL showed a lower age at event than carriers of MTHFR+/+ alone or aPL alone (38 +/- 24 versus 65 +/- 10 years, P < 0.05 and 38 +/- 24 versus 63 +/- 16 years, P < 0.05, respectively). In the same patients, mean plasma homocysteine measured by an ELISA method was significantly higher in the MTHFR+/+ + aPL group than in the MTHFR+/+ alone or aPL alone groups (P = 0.01). Antiphospholipid antibodies are as common as thrombophilic genotypes in patients with venous thrombosis, and the interaction of aPL with MTHFR+/+ may influence age at first event via elevated plasma homocysteine.

Apolipoprotein E polymorphisms in age-related macular degeneration in an Italian population.

OBJECTIVE: Apolipoprotein E (apoE) is an important regulator of cholesterol and lipid transport during compensatory synaptogenesis. Our purpose was to investigate the role of apoE gene polymorphisms in Italian patients with age-related macular degeneration (AMD). METHODS: We used the polymerase chain reaction technique to analyze apoE genotypes in 87 patients with AMD, in 47 age-matched controls and in 1,287 individuals from a general reference population. RESULTS: The frequency of allele epsilon4 carriers was significantly higher (p = 0.002) in the general population than in AMD patients, while the frequency of allele epsilon2 was higher in the patients (p = 0.069) with an increased risk for AMD in the patients versus the population-based controls (odds ratio = 1.7; 95% confidence interval: 1.0-2.9). Allele epsilon4 was associated with a decreased risk for AMD in the patients versus the population-based controls (odds ratio = 0.3; 95% confidence interval: 0.1-0.8). CLINICAL RELEVANCE: These data suggest that apoE testing may represent a tool for the evaluation of the relative risk of AMD. Consequently, a preventive strategy can be initiated at an early stage of the disorder. CONCLUSION: The apoE gene polymorphism showed a significant association with the risk of AMD. The lower frequency of the epsilon4 allele in AMD patients suggests that the apoE gene could play a protective role in the pathogenesis of the disease. In contrast, the epsilon2 allele was found associated with a slightly increased risk of AMD, although we did not find a statistically significant effect.

The effect of the interleukin-6 c/g-174 polymorphism and circulating interleukin-6 on fibrinogen plasma levels.

BACKGROUND AND OBJECTIVES: C-reactive protein (C-RP) levels correlate with fibrinogen values and are predictive of coronary artery disease. Interleukin-6 (IL-6) strongly regulates the production of C-RP. A polymorphism (C/G-174) within the IL-6 gene has been shown to affect IL-6 gene expression and plasma concentrations. DESIGN AND METHODS: In 598 asymptomatic employees of a hospital in Southern Italy, we investigated the association between IL-6 C/G-174 gene variants and plasma fibrinogen levels. RESULTS: Subjects with IL-6 plasma levels >2.0 pg/mL had a higher body mass index (BMI) (24.5+/-1.2) than subjects with IL-6 levels below this cut-off value (23.7+/-1.2; p =0.005). No association was found with sex, cigarette smoking, or alcohol consumption (p always>0.05). When the whole sample was analyzed according to the IL-6 C/G-174 polymorphism, there was no difference with respect to age, sex, alcohol consumption, cigarette smoking, total cholesterol, triglycerides, and body mass index. Median plasma fibrinogen levels, as well as carriers of plasma levels of IL-6 >2.0 pg/mL and C-RP >0.33 mg/L, were similar among subjects with different IL-6 genotypes. Similarly, no difference was observed when only carriers of plasma levels of IL-6 >2.0 pg/mL were analyzed, whereas in those with C-RP >0.33 mg/L IL-6 GG carriers had significantly lower plasma fibrinogen levels. INTERPRETATION AND CONCLUSIONS: The investigation of the IL-6 C/G-174 polymorphism does not seem to be a useful tool for predicting raised plasma fibrinogen levels.

C-reactive protein in offspring is associated with the occurrence of myocardial infarction in first-degree relatives.

The relevance of elevated levels of C-reactive protein (CRP) in cardiovascular disease is gaining increasing recognition. A family history of coronary artery disease is a major determinant of coronary artery disease in the offspring. In a cohort of 1048 individuals without clinical evidence of atherosclerosis, we investigated the relationships between CRP levels and a family history of myocardial infarction. We measured CRP, fibrinogen, plasminogen activator inhibitor-1, total cholesterol, triglycerides, and some genetic polymorphisms: plasminogen activator inhibitor-1 (4G/5G), fibrinogen (Bbeta-chain G-->A(-455)), and angiotensin-converting enzyme insertion/deletion (I/D). Clinical data were collected by a World Health Organization-modified questionnaire for cardiovascular disease. When compared with subjects without first-degree relatives who had suffered a myocardial infarction (n=867), subjects with such first-degree relatives (n=181) were older (P=0.001), more often hypertensive (P<0. 001), and homozygous for the 4G allele (4G/4G) of the plasminogen activator inhibitor-1 gene (P=0.003). In addition, they had a higher body mass index (P=0.036), raised plasma fibrinogen (P<0.007) and total cholesterol (P<0.001) concentrations, and CRP levels >0.33 mg/L (P=0.005). In a multiple logistic regression analysis, age (odds ratio [OR] 1.03, 95% confidence interval [95% CI] 1.01 to 1. 05), total cholesterol (OR 1.35, 95% CI 1.11 to 1.65), plasminogen activator inhibitor-1 4G/4G (OR 1.72, 95% CI 1.20 to 2.45), and CRP levels >0.33 mg/L (OR 1.75, 95% CI 1.05 to 2.91) were all independently associated with a positive family history of myocardial infarction. We therefore conclude that raised levels of CRP independently identify the offspring of patients with a myocardial infarction.

Coexistence of factor V Leiden and Factor II A20210 mutations and recurrent venous thromboembolism.

Patients carrying the FV Leiden or the FII A20210 mutation have a high risk of venous thromboembolism. Among 542 patients with a documented diagnosis of deep venous thrombosis in one leg consecutively referred for a thrombophilic work-up, we have retrospectively assessed the rate of objectively documented previous recurrence in carriers of both FV Leiden and FII A20210 mutations. Eighty-two patients had experienced 115 episodes of recurrent venous thromboembolism. The rate of recurrent venous thromboembolism was 29.2% among subjects with and 14.5% in those without deficiencies of natural anticoagulant proteins (p = 0.055), and 24.6% among patients with and 14.0% in those without antiphospholipid antibodies (p = 0.036). The frequency of having a recurrent thromboembolism was 16.2%, 20.0%, and 36.4% among carriers of FV Leiden, FII A20210 mutation, or both gene defects, respectively, and 12.8% in subjects carrying neither mutation (p for trend = 0.004). When adjusted for age, sex, and thrombophilic risk factors, the rate was higher among patients with than in those without deficiencies of natural anticoagulant proteins (OR: 3.0; 95% CI: 1.2-7.5), aPL 2.5 (95% CI: 1.3-4.9), or both FV Leiden and FII A20210 gene mutations (OR 4.8; 95% CI: 1.9-12.2). The rate of previous recurrent venous thromboembolism was significantly higher in subjects carrying both FV Leiden and FII 20210 mutations and was comparable to that observed in subjects with deficiencies of natural anticoagulant proteins or antiphospholipid antibodies.

Anticardiolipin antibodies in patients with liver disease.

OBJECTIVE: Our aim was to test the hypothesis that anticardiolipin antibodies (aCL) may cause an antiphospholipid syndrome and thrombotic events in patients with liver disease. METHODS: aCL were measured in 116 healthy controls and 372 patients with liver disease of different stage and etiology: 136 cases secondary to hepatitis C virus (HCV) infection, 139 due to hepatitis B virus (HBV) infection, 69 with alcoholic liver damage, and 28 cryptogenic in origin. Prior thrombotic events were recorded. The results were related to age, gender, stage, severity, and etiology of the liver disease, as well as to the occurrence of organ- and nonorgan-specific autoantibodies. RESULTS: aCL were positive in 4.4% of controls and in 18.8% of patients (p < 0.0002). Patients with aCL were more frequently men with an advanced cirrhosis and simultaneous occurrence of anti-smooth-muscle antibodies (ASMA) in serum (p < 0.0006); their liver damage was often secondary to HBV (37.3%) or alcohol abuse (18.5%). At conditional logistic regression analysis, only the presence of ASMA (odds ratio [OR] = 3.02, 95% confidence interval [CI] 1.7-5.5, p = 0.0003), HBV (OR = 3.4, 95% CI 1.6-7.2, p = 0.0013), or alcoholic liver disease (OR = 5.3, 95% CI 2.3-12.2, p = 0.0001) were independently associated with aCL. Thrombosis was encountered in 24 patients (6.4%). At conditional logistic regression analysis, thrombosis was significantly associated with advanced age (OR = 1.07, 95% CI 1.0-1.1, p = 0.0094), development of hepatocellular carcinoma (OR = 17.8, 95% CI 1.6-196.0, p = 0.01), HBV etiology (OR = 6.3, 95% CI, 1.6-24.6, p = 0.0076), or cryptogenic liver disease (OR = 54.8, 95% CI 5-599.9, p = 0.001). Of the five patients with newly documented portal thrombosis during the follow-up, only one tested positive for aCL. CONCLUSIONS: In patients with nonautoimmune liver disease, aCL production is an epiphenomenon of the liver damage and is not associated with thrombotic complications. These data do not support the hypothesis that HCV is a cause of the antiphospholipid syndrome.

Genetic polymorphism of 5,10-MTHFR reductase gene in offspring of patients with myocardial infarction.

A family history of myocardial infarction is a major determinant of ischemic disease. A C->T677 polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene has been identified as a cause of mild hyperhomocysteinemia, a risk factor for arterial thrombosis. We have investigated the relationship between the MTHFR TT genotype and a family history of myocardial infarction in a cohort of 982 apparently healthy individuals. Subjects whose first-degree relatives suffered from a myocardial infarction, showed raised median age (p <0.001), total cholesterol (p <0.001) and plasma fibrinogen (p = 0.023) and a higher than normal frequency of C-reactive protein levels >0.33 mg/dl (p = 0.012). Moreover, when compared to subjects without such family history, a higher number of homozygotes for the T allele of the MTHFR gene (p = 0.027), and of the 4G allele of the plasminogen activator inhibitor-1 gene (p = 0.002) was found in the subsetting of the offspring of patients with myocardial infarction. In a multiple logistic regression analysis, age (OR 1.02 [95%-CI: 1.00-1.05]), total cholesterol (OR 1.40 [95%-CI: 1.14-1.71]), C-reactive protein levels >0.33 mg/l (OR: 1.87 [95%-CI: 1.10-3.20]), plasminogen activator inhibitor-1 4G/4G (OR: 1.84 [95%-CI: 1.27-2.66]), and MTHFR TT genotype (OR 1.62 [95%-CI: 1.08-2.42]), were all associated with a family history of myocardial infarction. Thus, the MTHFR TT genotype independently accounts for the risk of a family history for myocardial infarction in the present setting.

The use of frozen-thawed platelet-derived phospholipids as a confirmatory test for the diagnosis of lupus anticoagulants. Comparison with two commercial confirmatory system tests.

Lupus anticoagulants (LAs) belong to acquired circulating anticoagulants interfering with phospholipid-dependent coagulation tests. Owing to the remarkable variability among patients, SSC guidelines recommend more than one test to detect and confirm the presence of LAs. However, this is an expensive procedure and greatly raises the work load of the laboratory. A standardised platelet-derived phospholipid preparation was obtained and platelet neutralisation (PNP) procedures with APTT and DRVVT reagents were performed on plasmas from 16 patients with LAs and from 41 control subjects. In comparisons, STAclot-PNP and DVVconfirm clotting assays were conducted. PNP by using APTT or DRVVT reagents showed intra-assay coefficient of variation of 1.6 and 1.8%, whereas inter-assays coefficient of variations were 6.8 and 5.1%, respectively. A complete concordance was achieved between STAclot-PNP and PNP by using APTT reagents and between DVV-confirm and PNP with DRVVT reagents, demonstrating a high reliability of both the PNP-based assays. This consistency indicates that the standardised platelet-derived phospholipid preparation obtained allows for reliable, reproducible, and cheap PNP-based confirmatory assays for LAs testing.

Determining sulfur-containing amino acids by capillary electrophoresis: a fast novel method for total homocyst(e)ine human plasma.

A high-performance capillary electrophoresis (HPCE) method based on laser-induced fluorescence detection is presented here. It enables the determination of sulfur-containing amino acids within 15 min. Fluorescence of sulfur-containing amino acids in plasma is linear over a range of 50-150 micromol/L for L-methionine, 5-100 micromol/L for L-homocysteine, and 50-200 micromol/L for L-cysteine. For homocysteine, we were able to detect 1 fmol injected, equivalent to a plasma concentration of 10 nmol/L. A similar sensitivity is present for cysteine, an even lower one being found for methionine. The intra- and interassay relative standard deviations are < 1%. High-performance liquid chromatography (HPLC) methods are commonly employed for quantifying blood concentrations of sulfur-containing amino acids. A comparative analysis of HPCE and HPLC quantitation of homocysteine has been carried out in 61 blood samples. Plasma concentrations measured by HPCE were in good agreement with those obtained employing an HPLC-based method, a satisfactory correlation being observed between the concentrations obtained by the two methods (r= 0.9972). Thus, the HPCE-based procedure presented here for the measurement of sulfur-containing amino acids in plasma is a simple, fast, accurate, and very sensitive method, suitable for routine determinations in clinical studies.

Prothrombotic genetic risk factors and the occurrence of gestational hypertension with or without proteinuria.

Gestational hypertension with or without proteinuria is a multifactorial disease in which the presence of a hypercoagulable state has been suggested. The prothrombin G20210A, the Factor V (FV) Leiden mutations, and the C677T 5-10 methylenetethrahydrofolate reductase (MTHFR) polymorphism were investigated in 140 women with gestational hypertension and in 216 normotensive women from Southern Italy. Nine controls (4.1%) and 16 cases (11.4%; OR: 2.96, 95% CI: 1.27-6.91) carried the prothrombin A20210 allele. FV Leiden mutation was observed in 4 controls (1.8%) and 11 cases (7.9%; OR: 4.53, 95% CI: 1.41-14.53). The TT MTHFR genotype was found in 36 controls (16.6%) and 34 cases (24.4%: OR: 1.61, 95% CI: 0.96-2.74). The impact of potential confounding variables was evaluated using a logistic regression analysis. Nulliparity, Factor V Leiden and prothrombin A20210 carrier status resulted to be independent risk factors of having gestational hypertension with or without proteinuria. Imbalance of haemostasis, through prothrombotic genetic factors, may predispose to the occurrence of gestational hypertension.

Fibrinogen plasma levels in an apparently healthy general population--relation to environmental and genetic determinants.

Elevated fibrinogen levels are an independent risk factor for cardiovascular ischemic disease. We investigated the relationship between cardiovascular ischemic risk factors, the fibrinogen Bbeta-chain G/A(-455) polymorphism and plasma fibrinogen levels in 989 apparently healthy subjects. Fibrinogen values were higher in subjects with C reactive protein (C-RP) >0.33 mg/dl, BMI >23.9 kg/m2, total cholesterol >4.84 mmol/l, triglycerides > 1.02 mmol/l, PAI-1 antigen >12.2 ng/ml, carriers of the A allele, first-degree relative history of coronary artery disease, or consuming >10 cigarettes per day (p<0.01). Men and ethanol drinkers showed lower plasma fibrinogen levels (p<0.01). The multivariate analysis confirmed the independent effect of C-RP, age, BMI, total cholesterol, gender, PAI-1, -455 G/A polymorphism, (p<0.05). BMI, total cholesterol, PAI-1, alcohol and smoking habit raised with the increase of age and differed between sexes. The A(-455) allele increasing effect was significant in women, especially in subjects aged <30 years, and in men aged <43 years. These results indicate that environmental factors contributed to a larger extent to fibrinogen variability, whereas the A(-455) allele was associated with a steeper increase in younger age quartiles.

Genetic susceptibility to pregnancy-related venous thromboembolism: roles of factor V Leiden, prothrombin G20210A, and methylenetetrahydrofolate reductase C677T mutations.

OBJECTIVE: This study's objective was to evaluate the association between venous thromboembolism during pregnancy and the postpartum period and the factor V Arg 506 Gln (factor V Leiden), the prothrombin G20210A, and methylenetetrahydrofolate reductase C677T polymorphisms. STUDY DESIGN: In this case-control study 42 case patients and 213 control subjects (parous age-matched women without history of thrombosis) were genotyped for all the polymorphisms. Moreover, antiphospholipid antibodies and protein C, protein S, and antithrombin III deficiencies were investigated in each case. RESULTS: Ten case patients (23.8%) and 4 control subjects (1.9%; odds ratio 16.3, 95% confidence interval 4.8-54.9) carried the factor V Leiden mutation; 13 case patients (31.0%) and 9 control subjects (4.2%; odds ratio 10.2, 95% confidence interval 4.0-25.9) were carriers of the prothrombin G20210A allele. Finally, 12 case patients (28.6%) and 34 control subjects (16.0%; odds ratio 2.1, 95% confidence interval 1.0-4.5) were homozygotes for methylenetetrahydrofolate reductase C677T. Overall, mutations were found in 25 case patients (59.5%) and 47 control patients (22.2%; odds ratio 5.2, 95% confidence interval 4.9-19.6). One patient carried the antithrombin III deficiency and 1 the protein S deficiency, whereas 2 women had a primary antiphospholipid syndrome. CONCLUSIONS: The significant risk estimates of having a pregnancy-related venous thromboembolism in the presence of the prothrombotic genetic risk factors analyzed suggest to screen for these mutations women with a personal history of thromboembolic events during pregnancy or the postpartum period.

Identifying human platelet glycoproteins IIb and IIIa by capillary electrophoresis.

Glanzmann thrombasthenia (GT) is an inherited hemorrhagic defect due to a failure of the platelet membrane glycoprotein (GP) IIb-IIIa complex. Capillary electrophoresis (CE) analysis of solubilized platelet membranes from normal individuals showed the presence of two peaks with a migration time of 27 and 29 min, respectively. An excellent run-to-run and day-to-day reproducibility of the technique (< 1% variation of the retention time) was documented. Using an automated Ferguson method, the apparent molecular masses were 100.0 kDa and 138.5 kDa, respectively. Immunoprecipitation with monoclonal antibodies anti-GP IIIa (B59.2.1) and anti-IIb (61.9.1.3) showed the two peaks as IIIa and IIb, respectively. Electropherograms of a GT young man showed the lack of both peaks. Less than 50% of each peak was present in his parents. Polyacrylamide gel electrophoresis (PAGE), immunoblotting, and flow cytometry analyses showed that GP IIb and IIIa were undetectable in the platelet membranes from the propositus, half of the normal amount being present in both parents. These findings indicate CE to be a rapid, sensitive and reliable tool to investigate patients with abnormalities of the GP IIb-IIIa complex.

Increased risk for venous thrombosis in carriers of the prothrombin G-->A20210 gene variant.

BACKGROUND: A mutation in the prothrombin gene (G-->A20210) has been associated with higher plasma prothrombin levels and an increased tendency for venous thrombosis. OBJECTIVE: To determine whether the prothrombin A20210 allele is independently associated with the occurrence of venous thrombosis. DESIGN: Case-control study. SETTING: Two thrombosis centers in southern Italy. PATIENTS: 281 consecutive patients with venous thrombosis confirmed by objective tests and 850 controls. MEASUREMENTS: Medical history was collected on standardized questionnaires. The presence of prothrombin G-->A2020 and factor V Leiden mutations was determined by polymerase chain reaction. The presence of anticoagulant factors and prothrombin activity was determined by tests of function. RESULTS: In 150 controls, increased prothrombin activity (P < 0.001) was associated with the prothrombin A20210 allele. This allele was more frequent in patients than in controls (8.01% compared with 2.29%; P < 0.001) and was associated with an increased risk for thrombosis (odds ratio, 3.88 [95% CI, 2.23 to 6.74]). The increased prevalence of this allele was independent of the presence of the factor V Leiden mutation. After adjustment for sex, age, arterial thrombosis, and factor V Leiden mutation, the risk was still significantly elevated (odds ratio, 3.13 [CI, 1.89 to 5.21]). Moreover, the overall prevalence of inherited coagulation abnormalities was significantly higher in patients with thrombosis of the lower extremities than in patients with thrombosis of the upper extremities (odds ratio, 3.77 [CI, 1.10 to 12.93]). Fourteen patients carried both the prothrombin G-->A20210 and factor V Leiden mutations. CONCLUSIONS: The prothrombin A20210 allele is independently associated with the occurrence of venous thrombosis, particularly in patients with a history of thrombosis of the lower extremities.

The methylenetetrahydrofolate reductase TT677 genotype is associated with venous thrombosis independently of the coexistence of the FV Leiden and the prothrombin A20210 mutation.

A polymorphism, C-->T677, in the methylenetetrahydrofolate reductase (MTHFR) gene has been identified as a cause of mild hyperhomocysteinemia, a risk factor for venous thrombosis. We have investigated the frequency of the TT genotype in 277 consecutive patients with confirmed deep venous thrombosis and 431 healthy subjects. The TT MTHFR genotype was more frequent in patients than in controls (25.6% vs. 18.1%; p = 0.016). The risk of thrombosis among carriers of this genotype was significantly increased [odds ratio: 1.6 (95% CI: 1.1-2.3)]. The estimated risk associated with the TT genotype was 2.0 (95% CI: 1.3-3.1) in subjects with (n = 122), and 1.3 (95% CI: 0.8-2.0) in those without (n = 155) predisposing (hereditary, acquired or circumstantial) risk factors for venous thrombosis. Factor V Leiden and prothrombin G-->A20210 are known risk factors for venous thrombosis. After stratification for FV Leiden and prothrombin A20210 mutations, a significant association was also observed. After adjustment for sex, FV Leiden and prothrombin A20210 mutation, the estimated risk of venous thrombosis among carriers of the TT MTHFR genotype was 1.7 (95% CI: 1.2-2.6). The TT MTHFR genotype is independently associated with venous thrombosis, mainly among individuals with a high risk profile.

PAI-1 plasma levels in a general population without clinical evidence of atherosclerosis: relation to environmental and genetic determinants.

Plasminogen activator inhibitor-1 (PAI-1) plasma levels have been consistently related to a polymorphism (4G/5G) of the PAI-1 gene. The renin-angiotensin pathway plays a role in the regulation of PAI-1 plasma levels. An insertion (I)/deletion (D) polymorphism of the angiotensin-converting enzyme (ACE) gene has been related to plasma and cellular ACE levels. In 1032 employees (446 men and 586 women; 22 to 66 years old) of a hospital in southern Italy, we investigated the association between PAI-1 4G/5G and the ACE I/D gene variants and plasma PAI-1 antigen levels. None of the individuals enrolled had clinical evidence of atherosclerosis. In univariate analysis, PAI-1 levels were significantly higher in men (P<.001), alcohol drinkers (P<.001), smokers (P=.009), and homozygotes for the PAI-1 gene deletion allele (4G/4G) (P=.012). Multivariate analysis documented the independent effect on PAI-1 plasma levels of body mass index (P<.001), triglycerides (P<.001), sex (P<.001), PAI-1 4G/5G polymorphism (P=.019), smoking habit (P=.041), and ACE I/D genotype (P=.042). Thus, in addition to the markers of insulin resistance and smoking habit, gene variants of PAI-1 and ACE account for a significant portion of the between-individual variability of circulating PAI-1 antigen concentrations in a general population without clinical evidence of atherosclerosis.

The PAI-1 gene locus 4G/5G polymorphism is associated with a family history of coronary artery disease.

A family history of ischemic events is a major determinant of coronary artery disease (CAD). Plasma levels of plasminogen activator inhibitor 1 (PAI-1) modulate this risk. A deletion/insertion polymorphism within the PAI-1 locus (4G/5G) affects the expression of this gene. We investigated the relationship between the PAI-1 4G/5G polymorphism in 1179 healthy employees of our institution and the occurrence of CAD in their first-degree relatives. A family history of documented ischemic coronary disease was assessed by a modified WHO questionnaire. The PAI-1 4G/5G polymorphism was evaluated by polymerase chain reaction and endonuclease digestion. The group with a first-degree relative who had suffered from a coronary ischemic episode had a higher number of homozygotes for the deleted allele (4G/4G) of the PAI-1 gene compared with subjects without such a family history (odds ratio [OR] = 1.62, 95% confidence interval [CI]=1.17 to 2.25; P=.005). The frequency of the 4G allele was abnormally high as well (OR=1.29, 95% CI=1.04 to 1.60; P=.025). The individuals with a positive family history were older (P<.001) and exhibited a higher body mass index (P=.033) and total cholesterol levels (P<.001) than those without. In a multiple logistic regression analysis, age (P=.006) and PAI-1 4G/4G (P=.024) independently contributed to a family history of coronary heart disease, with 4G/4G carriers exhibiting a more frequent family history of CAD (OR=1.60). The PAI-1 4G/5G polymorphism to some extent thus accounts for the risk of CAD related to a family history for such an event. These findings support the hypothesis that the 4G variant is a transmissible coronary risk factor.