Dayse Maria Lourenço

A second mutation in the methylenetetrahydrofolate reductase gene and the risk of venous thrombotic disease

We assessed the effect of a recently described mutation in the MTHFR gene (1298 A → C) on the risk of deep venous thrombosis (DVT) by determining its prevalence in 190 patients with verified DVT and in age‐, race‐ and gender‐matched controls. MTHFR 1298 A → C was found in 42.1% of patients and in 41.1% of controls. The OR for venous thrombosis was 1.07 (95% CI 0.70–1.65) for heterozygotes and 0.83 (95% CI 0.33–2.08) for homozygotes. The OR for the factor V Leiden (FVL) mutation was 3.40 (95% CI 1.22–9.48), for FII 20210 G → A was 5.22 (95% CI 1.12–24.2) and for MTHFR 677 C → T, 1.24 (95% CI 0.82–1.87). No significant increased risk for venous thrombosis was found when MTHFR 1298 A → C was coinherited with FVL (OR 2.85, 95% CI 0.88–9.23), FII 20210 G → A (OR 7.19, 95% CI 0.87–59.4) or MTHFR 677 C → T (OR 1.44, 95% CI 0.71–2.92). These data do not support a critical role of MTHFR 1298 A → C in the predisposition to DVT.

PROTHROMBIN G20210A MUTATION, AND NOT FACTOR V LEIDEN MUTATION, IS A RISK FACTOR FOR CEREBRAL VENOUS THROMBOSIS IN BRAZILIAN PATIENTS

Prothrombin G20210A mutation, factor (F)V Leiden mutation and oral contraceptive (OC) use were previously shown to be associated with an increased risk of cerebral venous thrombosis (CVT) [1–3]. We investigated the prevalences of prothrombin G20210A mutation, FV Leiden mutation and OC use in 42 consecutive patients with objectively confirmed diagnosis of CVT (median age of 28 years and 67% being women), and compared them with 134 healthy subjects, recruited from biologically unrelated acquaintances or partners of patients without history of venous thromboembolism (VTE) or known systemic diseases (median ageof34 years and 60% beingwomen). Prothrombin G20210A mutation was found in 16.7% of patients and 0.7% of the control group, yielding an odds ratio (OR) for CVT of 26.6 [95% confidence interval (CI): 3.2-223.5]. FV Leiden mutation was detected in 4.8% of patients and in 2.2% of the control group (OR: 2.2, 95% CI: 0.4–13.5). It is noteworthy that the majority of carriers of prothrombin G20210A mutation and FV Leiden mutation were Caucasian. Our prevalence of prothrombin G20210A mutation was similar to an Italian study (20%) [3], and to a previous Brazilian report with 14 CVT patients (14.3%) [4]. In accordance to previous reports [2,3], prothrombin G20210A mutation was a significant risk factor for CVT. The proportion of patients carrying FV Leiden was also similar to the previous Brazilian report (7.1%) [4], but lower as compared with the Italian series (15%) [3]. The high prevalence of the prothrombin G20210A mutation in Brazilian patients may derive from the ethnic background of the study populations. Brazilian general population has an extremely heterogeneous ethnic composition, unevenly distributed in the country with variable degrees of admixtures. Brazilian citizens of Caucasian descent originate mainly from Southern Europe (specially Portugal, Italy and Spain), where prevalence of the prothrombin G20210A mutation is twice as high as compared to Northern Europe [5]. Patients and controls had a heterogeneous ethnic distribution: among patients, 55% were Caucasians and 43% were of Caucasian and Black descent and among controls, 20% were Caucasians and 80% were of Caucasian and Black descent. It is important to point out that the high OR for the prothrombin G20210A mutation may be in part attributable to the relatively low frequency of Caucasians among controls, since carriers of prothrombin G20210A mutation were in general Caucasians. Eighty-nine percent of women had thrombosis between 20 and 50 years of age (Fig. 1). For this age group, 60% of the patients were OC users and 20% were in the puerperium when CVT was diagnosed. Among the five women with inherited thrombophilia, there were four who were also OC users. Among patients, 60% were OC users as compared to 12.5% of a historical control group of 40 consecutive women aged 20–50 that came as outpatients for reasons other than thrombosis (OR 1⁄4 10.5, 95% CI: 3.1–36.0). Our results confirmed previous findings of a higher frequency of CVT in women than in men, mostly during reproductive age when there is an excessive exposure to exogenous (OC) and endogenous (pregnancyrelated) sex hormones [1,3]. Eleven patients had acquired disorders that might be associated with CVT such as nephrotic syndrome, bacterial meningitis, antiphospholipid syndrome, Behçet’s disease, Crohn’s disease, sinusitis, homocystinuria, essential thrombocythemia and breast cancer. Both cases of CVT associated with meningitis were male patients with prothrombin G20210A mutation, and the patient with Crohn’s disease was also OC user. The prevalence of acquired disorders was higher in men (50%) than in women (14%), P 1⁄4 0.02. Overall, we found that among 42 consecutive patients with CVT, 72% had at least one acquired risk factor or predisposing condition for venous thromboembolism, six of whom were also carriers of prothrombin G20210A mutation (n 1⁄4 5) and FV Leiden mutation (n 1⁄4 1). Only 28% of patients had CVT spontaneously. Among the seven carriers of prothrombin G20210A mutation, only two subjects had no other known acquired predisposing condition for venous thromboembolism, suggesting that this mutation is usually associated with other risk factors in patients with CVT. Patients were re-evaluated 30 days after CVT diagnosis by two neurologists unaware of the genotypic results, and the functional clinical outcome was graded on the modified Rankin Scale [6]. Most patients (71%) had no activity limitations. There Correspondence: D. Lourenço, Division of Haematology and Transfusion Medicine., Universidade Federal de São Paulo., R. Botucatu, 740 3 o andar São Paulo-SP, Brazil. Tel.: +55 11 55764237; fax: +55 11 55718806; e-mail: dayse@webmail. epm.br

Tuberculosis: an uncommon cause of cerebral venous thrombosis?

Several infectious etiologies are related to cerebral venous thrombosis (CVT), but a review of literature showed only few cases related to tuberculosis (TB), and only one with neurological manifestations. We report an unusual case of CVT related to TB and mutation in prothrombin gene. A 38-man black presented abrupt right hemiparestesis, and hemiparesis. Investigations revealed CVT. Cerebral spinal fluid (CSF) examination evidenced an infection by Mycobacterium. He was heterozygous for G20210A prothrombin mutation. Probably, hypercoagulability mechanisms of TB, added to mutation of prothrombin gene increase the risk of CVT.

The role of IL-6, IL-8 and MCP-1 and their promoter polymorphisms IL-6-174GC, IL-8-251AT and MCP-1-2518AG in the risk of venous thromboembolism: A case-control study

INTRODUCTION Cytokines increased the risk of venous thromboembolism (VTE) in some case-control studies, but not in a prospective study. Data concerning the role of cytokines in the risk of VTE are limited. We examined in a case-control study the association of VTE and levels of interleukin (IL)-6, IL-8 and monocyte chemotactic protein-1 (MCP-1) and assessed whether promoter polymorphisms (IL-6 -174GC, IL-8 -251AT, MCP-1 -2518AG) would affect the thrombotic risk and cytokine levels. MATERIALS AND METHODS The study included 119 patients (94 women) with a first event of VTE aged between 18-60 years, and 126 healthy controls (100 women) matched for age (±5 years). Blood was collected >7 months after the thrombotic event. Odds ratios (ORs) were calculated per increase of cytokines levels by 1 pg/mL. RESULTS ORs adjusted for age and sex were 1.520 [95% Confidence Interval (CI) 1.177 - 1.962] for IL-6, 1.095 (95% CI 1.002 - 1.196) for IL-8 and 1.000 (0.988 - 1.012) for MCP-1. With additional adjustment for ethnic composition, body mass index (BMI) and high sensitive C-reactive protein (hs-CRP), risk estimates remained significant for IL-6 and became of borderline statistical significance for IL-8. Polymorphisms did not influence the thrombotic risk and the cytokine levels in study participants. CONCLUSION VTE was associated with IL-6 and IL-8 levels, and for IL-6 this association was independent of BMI and hs-CRP. Thus far, a causal relationship between inflammation and VTE remains to be clarified and more prospective data are warranted.

Effect of estrogen-progestin hormonal replacement therapy on plasma antithrombin III of postmenopausal women

BACKGROUND This study was performed to evaluate antithrombin III levels in postmenopausal women receiving hormonal replacement treatment. METHODS It is a prospective randomized study concerning 19 postmenopausal patients, aged 40 to 65 years, who received either continuous daily oral equine conjugated estrogen 0.625 mg (group A, N=10) or daily transdermal 17beta-estradiol 50 microg (group B, N=9). Medroxyprogesterone acetate (5 mg/day, 14 days monthly) was given to all patients. Blood samples were obtained before and after 3, 6, 9 and 12 months of treatment. Coagulation tests included Antithrombin III (functional method), prothrombin time, partial activated prothrombin time, thrombin time, factor V, fibrinogen, platelet count and euglobulin lysis time. Friedman analysis of variance and Mann-Whitney test were used for statistical analysis. RESULTS Antithrombin III level was reduced (p<0.05) in group A but not in group B, although it remained within normal range. No changes were detected in the other coagulation tests. CONCLUSIONS These data suggest that oral conjugated estrogen replacement reduces functional ATIII, whereas transdermal estradiol replacement therapy does not modify it.

The clinical impact of MTHFR polymorphism on the vascular complications of sickle cell disease

Sickle cell disease (SCD) is one of the most common inherited diseases in the world and the patients present notorious clinical heterogeneity. It is known that patients with SCD present activation of the blood coagulation and fibrinolytic systems, especially during vaso-occlusive crises, but also during the steady state of the disease. We determined if the presence of the factor V gene G1691A mutation (factor V Leiden), the prothrombin gene G20210A variant, and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism may be risk factors for vascular complications in individuals with SCD. We studied 53 patients with SCD (60% being women), 29 with SS (sickle cell anemia; 28 years, range: 13-52 years) and 24 with SC (sickle-hemoglobin C disease; 38.5 years, range: 17-72 years) hemoglobinopathy. Factor V Leiden, MTHFR C677T polymorphism, and prothrombin G20210A variant were identified by PCR followed by further digestion of the PCR product with specific endonucleases. The following vascular complications were recorded: stroke, retinopathy, acute thoracic syndrome, and X-ray-documented avascular necrosis. Only one patient was heterozygous for factor V Leiden (1.8%) and there was no prothrombin G20210A variant. MTHFR 677TT polymorphism was detected in 1 patient (1.8%) and the heterozygous form 677TC was observed in 18 patients (34%, 9 with SS and 9 with SC disease), a prevalence similar to that reported by others. No association was detected between the presence of the MTHFR 677T allele and other genetic modulation factors, such as alpha-thalassemia, beta-globin gene haplotype and fetal hemoglobin. The presence of the MTHFR 677T allele was associated with the occurrence of vascular complications in SCD, although this association was not significant when each complication was considered separately. In conclusion, MTHFR C677T polymorphism might be a risk factor for vascular complications in SCD.

Risk factors, biochemical markers, and genetic polymorphisms in early coronary artery disease

OBJECTIVE To assess the risk factors, lipid and apolipoprotein profile, hemostasis variables, and polymorphisms of the apolipoprotein AI-CIII gene in early coronary artery disease (CAD). METHODS Case-control study with 112 patients in each group controlled by sex and age. After clinical evaluation and nutritional instruction, blood samples were collected for biochemical assays and genetic study. RESULTS Familial history of early CAD (64 vs 39%), arterial hypertension (69 vs 36%), diabetes mellitus (25 vs 3%), and previous smoking (71 vs 46%) were more prevalent in the case group (p<0.001). Hypertension and diabetes were independent risk factors. Early CAD was characterized by higher serum levels of total cholesterol (235 +/-6 vs 209 +/- 4 mg/dL), of LDL-c (154 +/- 5 vs 135 +/- 4 mg/dL), triglycerides (205 +/- 12 vs 143 +/- 9 mg/dL), and apolipoprotein B (129 +/- 3 vs 105 +/- 3 mg/dL), and lower serum levels of HDL-c (40 +/- 1 vs 46 +/- 1 mg/dL) and apolipoprotein AI (134 +/- 2 vs 146 +/- 2mg/dL) [p<0.01], in addition to an elevation in fibrinogen and D-dimer (p<0.02). The simultaneous presence of the rare alleles of the APO AI-CIII genes in early CAD are associated with hypertriglyceridemia (p=0.03). CONCLUSION Of the classical risk factors, hypertension and diabetes mellitus were independently associated with early CAD. In addition to an unfavorable lipid profile, an increase in the thrombotic risk was identified in this population. An additive effect of the APO AI-CIII genes was observed in triglyceride levels.

Factor V Arg306 Thr (factor V Cambridge) and factor V Arg306 Gly mutations in venous thrombotic disease

We investigated the prevalence of two reported mutations of the factor V gene (factor V Arg306 → Thr, or factor V Cambridge, and factor V Arg306 → Gly) in 104 relatively young patients with verified venous thrombosis and in 208 age‐, sex‐ and race‐matched controls, in order to establish whether the two mutations are associated with increased predisposition for venous thrombosis. PCR amplification followed by BstNI and MspI digestion was employed to determine the genotypes, and each mutation was confirmed by DNA sequencing. Among the controls, one individual was found to be heterozygous for the factor V Arg306 → Thr mutation and one heterozygous for the factor V Arg306 → Gly mutation; none of the patients carried either mutation. Our findings do not support factor V Cambridge and factor V Arg306 → Gly as risk factors for venous thrombosis.

Effect of estrogen-progestin hormonal replacement therapy on blood coagulation and fibrinolysis in postmenopausal women

OBJECTIVE To evaluate antithrombin III (AT), thrombin (Fragment 1+2 [F1+2] and thrombin-antithrombin [TAT]) generation markers, as well as other coagulation parameters, such as prothrombin time, partial activated thromboplastin time, thrombin time, fibrinogen, euglobulin lysis time, and platelet count, in postmenopausal women after hormonal therapy. STUDY DESIGN Forty-five patients who received either 0.625 mg/day unopposed oral conjugated equine estrogen (CEE), 0.625 mg/day oral CEE plus medroxyprogesterone acetate (MP), or 50 microg/day transdermal 17beta-estradiol plus MP, were included. Tests were performed before (T0) and after 3 (T3), 6 (T6) and 12 (T12) months of treatment. AT was determined by an amidolytic method, whereas F1+2 and TAT complex were measured by ELISA. RESULTS There was a significant reduction in the AT level of patients who received oral CEE plus MP at T3. There was no AT reduction in patients taking either oral CEE alone or transdermal 17beta-estradiol plus MP. F1+2 increased in all patients, but it reached statistical significance only in patients receiving transdermal 17beta-estradiol MP at T3. CONCLUSIONS The CEE associated with MP treatment may reduce AT levels, whereas unopposed CEE or transdermal 17beta-estradiol plus MP does not change AT. These changes might not be clinically relevant in the general population; however, hormonal replacement therapy may increase the risk of thrombosis in women with congenital or acquired thrombophilia.

Hemorrhagic and thrombotic complications in patients with myeloproliferative diseases

OBJECTIVE To correlate the incidence of hemorrhage and thrombosis to bleeding time (BT) and platelet aggregation in 27 consecutive patients with myeloproliferative diseases (MPD). DESIGN Retrospective study. SETTING Public tertiary referral center. PATIENTS Eighteen patients with chronic myelogenous leukemia (CML), 5 with polycytemia vera (PV), 2 with essential thrombocytemia (ET) and 2 with idiopathic myelofibrosis (MF). Dukes BT and epinephrine-induced platelet aggregation were performed on the patients and on 10 healthy individuals. RESULTS Eleven patients presented symptoms (41%):9 with hemorrhage (33%) and 5 with thrombosis (19%). There were less symptomatic patients in the CML group (28%) than in the other MPD (67%), without statistical significance (Fisher, p = 0.06). Dukes BT was longer in symptomatic patients (Mann-Whitney, p < 0.05). Platelet aggregation was abnormal in 7 patients (26%) and 71% of them were symptomatic (Fisher, p = 0.07). CONCLUSIONS The high incidence of bleeding and thrombosis in patients with MPD was related to prolonged BT, but not to platelet aggregation abnormalities.