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Introduction Plasminogen activator inhibitor-1 (PAI-1) is the major physiological inhibitor of tissue-type plasminogen activator in plasma and the most important regulator of the fibrinolytic pathway. The 4G/5G polymorphism (rs1799889) in the PAI-1 promoter is associated with altered PAI-1 transcription. We have identified a new 4G/5G allele, in which a T is inserted near the 4G tract or replaces a G in the 5G tract, forming a T plus 4G (T4G) region. Materials and Methods This new variant was first identified in two women, one had experienced juvenile myocardial infarction, the other repeated miscarriage; both had increased PAI-1 plasma activity. In view of the important influence of this promoter region on PAI-1 protein plasma level, we performed in vitro evaluation of the effects of the T4G variant on the transcription activity of the PAI-1 gene promoter. Results and Conclusions In silico prediction analysis showed that presence of the T4G allele disrupts the E-Box region upstream of the T4G variant, altering the affinity of the target sequence for E-Box binding factors like upstream stimulatory factor-1 (USF-1). Basal T4G promoter activity was 50% higher compared to 4G and 5G variants, but it was less stimulated by USF-1 overexpression. We also analyzed the effects of IL-1β and IL-6 on the PAI-1 promoter activity of our three constructs and showed that the T4G variant was less affected by IL-1β than the other variants. These findings indicate that the T4G variant may be a novel risk factor for thrombotic events.

Thromboangiitis obliterans, also known as Buerger's disease, is a cause of juvenile lower limb ischaemia. Buerger's disease is idiopathic and one of diagnostic criteria is the absence of atherosclerotic risk factors other than smok- ing. A possible involvement of thrombophilia has been investigated and the role of hyperhomocysteinemia is still matter of discussion. We describe 9 patients with Buerger's disease followed-up for the past 3 years. We found a significant in- crease in circulating homocysteine levels (mean: 31.6 in patients vs 8.2 μmol/L in control subjects). We also analyzed the C677T mutation of MTHFR; 5/9 Buerger's patients were heterozygotes and 4/9 homozygotes for the mutation as com- pared with 3 heterozygotes in the control group. Our data, although preliminary, suggest a possible role of homocysteine in the pathogenesis of Buerger's disease as one of the causes of endothelial dysfunction. The role of MTHFR C677T vari- ant must be further evaluated in larger trials involving patients with Buerger's disease.

Background Acute myocardial infarction (AMI) in young women represent an extreme phenotype associated with a higher mortality compared with similarly aged men. Prothrombotic gene variants could play a role as risk factors for AMI at young age. Methods We studied Factor V Leiden, FII G20210A, MTHFR C677T and beta-fibrinogen -455G>A variants by real-time PCR in 955 young AMI (362 females) and in 698 AMI (245 females) patients. The data were compared to those obtained in 909 unrelated subjects (458 females) from the general population of the same geographical area (southern Italy). Results In young AMI females, the allelic frequency of either FV Leiden and of FII G20210A was significantly higher versus the general population (O.R.: 3.67 for FV Leiden and O.R.: 3.84 for FII G20210A; p Discussion and conclusion Our data confirm that young AMI in females is a peculiar phenotype with specific risk factors as the increased plasma procoagulant activity of FV and FII. On the contrary, the homozygous state for the 677T MTHFR variant may cause increased levels of homocysteine and/or an altered folate status and thus an increased risk for AMI, particularly in males. The knowledge of such risk factors (that may be easily identified by molecular analysis) may help to improve prevention strategies for acute coronary diseases in specific risk-group subjects.

Prothrombin G20210A gene variant (FII G20210A) is a risk factor for venous thrombotic disease while conflicting results have been reported for the risk of arterial thrombotic events. However, vascular episodes were absent in up to 40% of the 67 homozygotes for the G20210A described so far, which indicates that the clinical expression depends on additional risk/trigger factors. We describe six homozygotes for the G20210A variant, among which the first pair of siblings (cases n. 3 and 4) reported so far that displayed a strongly heterogeneous clinical outcome. Case 1, a female of 27 years, developed a full thrombosis of common femoral, superficial and popliteal veins. She assumed oral contraceptives in the last two years. Case n. 2, 34 years old, suffered of recurrent pregnancy loss in absence of any causative alteration. Cases n. 3 and n. 5 experienced arterial thrombotic disease, i.e., juvenile myocardial infarction (40 years old) and stroke (48 years old), respectively, in absence of other risk factors. Finally, cases n. 4 and 6 identified as homozygotes for the FII G20210A variant being consanguineous of symptomatic subjects bearing the variant, did not experience any episode of venous nor arterial disease. Both of them have chronic liver disease with an impairement of the prothrombin time INR. Thus, homozygotes for the G20210A are at risk for arterial (in addition to venous) thromobotic events; chronic liver disease might modulate this risk.

In the last decades we found many data concerning the association between a hypercoagulable state and its causes and adverse pregnancy outcome, in particular recurrent pregnancy loss (RPL). Although first studies were focused only on the association between thrombophilia and RPL, subsequent studies underlined also a potential role of antithrombotic treatment to prevent vascular complication such as venous thromboembolism (VTE) during pregnancy. Now, emerging data seem to be available also on the role of active thromboprophylaxis with heparin and pregnancy outcome. This review will be focused on the recent knowledge between thrombophilia, hypercoagulable state, RPL, VTE and future perspectives.

Background Pharmacogenetic testing for drug-metabolizing enzymes is not yet widely used in clinical practice. Methods In an attempt to facilitate the application of this procedure, we have compared two real-time PCR-based methods, the TaqMan and the LightCycler for the pharmacogenetic evaluation of CYP2C9*2/*3 polymorphisms. Results and conclusion Both procedures are suitable for pharmacogenetic studies. The TaqMan procedure was less expensive in terms of cost per sample, but the TaqMan apparatus is more expensive than the LightCycler apparatus.

Congenital thrombotic risk factors, oncological diseases and its therapies have been related to an increased occurrence of upper extremities deep venous thrombosis (UEDVT). We studied seven patients bearing lymphoma (one Hodgkin's and six non-Hodgkin's) who developed UEDVT, one at diagnosis and six during chemotherapy (two of these six cases had implantation of a central venous catheter and four received Growth Colony Stimulating Factors in addition to chemotherapy). Patients were screened for: factor V G1691A (Leiden), prothrombin G20210A, methylene tetrahydrofolate reductase (MTHFR) C677T mutations and antithrombin III, proteins C and S plasma activity. All patients were wild-type homozygotes for G20210A. One was heterozygote for factor V G1691A, the other 6 were wild-type homozygotes. Three of the 7 patients were homozygotes and 2 heterozygotes for the MTHFR mutation; the remaining 2 were wild-type homozygotes. Clotting inhibitor levels were normal in all patients. UEDVT in patients bearing haematological malignancies can occur irrespective of congenital thrombophilic alterations. However, in a subgroup of patients UEDVT could also depend on congenital thrombophilic alterations. A screening for inherited thrombophilia can identify high risk patients that could be specifically treated to prevent thrombotic complications.