The distribution of Factor V Leiden mutation

Venous thrombosis risk factors in pregnant women

Venous thromboembolism (VTE) is the third most common cause of death on Earth after myocardial infarctions and strokes, according to the World Health Organization (WHO). Pregnancy is a unique condition of woman, when enormous changes occur in functioning of the most important systems of homeostasis in a relatively short time. These are physiological hypercoagulation, slowing of blood flow, increase in circulating blood volume, etc. However, while being physiological, these changes increase the risks of venous thromboembolism by almost 6 times. In some cases, there appears an imbalance or dissociation between the functioning of natural antithrombotic systems and the activation of coagulation as a consequence of genetically or acquired determined causes (genetic thrombophilia, antiphospholipid syndrome, comorbidities, obstetric complications and other exogenous and endogenous factors). Accordingly, identification of risk factors, their systematization, and determination of VTE risks in pregnancy and puerperium is one of the most important tasks of clinical medicine. Various recommendations have appeared for practitioners during the last 10-15 years on the basis of the risk factors analysis in order to prevent VTE in pregnant women more effectively. Nevertheless, none of these recommendations can yet take into account all risk factors, although convenient scoring systems have emerged for risk assessment and clear recommendations on anti-thrombotic prophylaxis regimens in risk groups in recent years. This article will review historical understanding of thrombosis in pregnant women, progress in understanding VTE risk factors in pregnant women, and available reserves in identifying new risk factors during pregnancy and puerperium in order to stratify risks more efficiently.

Venous thrombosis risk factors in pregnant women

OBJECTIVES

Assess all risk factors of venous thromboembolism (VTE) in pregnancy and puerperium.

METHODS

Different guidelines for VTE prevention have been analyzed.

RESULTS

Various recommendations have appeared for practitioners during the last 10-15 years on the basis of the risk factors analysis in order to prevent VTE in pregnant women more effectively. Nevertheless, none of these recommendations can yet take into account all risk factors, although convenient scoring systems have emerged for risk assessment and clear recommendations on anti-thrombotic prophylaxis regimens in risk groups in recent years.

CONCLUSIONS

VTE is the third most common cause of death on Earth after myocardial infarctions and strokes, according to the World Health Organization. Pregnancy is a unique condition of woman, when enormous changes occur in functioning of the most important systems of homeostasis in a relatively short time. These are physiological hypercoagulation, slowing of blood flow, increase in circulating blood volume, etc. However, while being physiological, these changes increase the risks of venous thromboembolism by almost six times. In some cases, there appears an imbalance or dissociation between the functioning of natural antithrombotic systems and the activation of coagulation as a consequence of genetically or acquired determined causes (genetic thrombophilia, antiphospholipid syndrome, comorbidities, obstetric complications and other exogenous and endogenous factors). Accordingly, identification of risk factors, their systematization, and determination of VTE risks in pregnancy and puerperium is one of the most important tasks of clinical medicine. This article will review historical understanding of thrombosis in pregnant women, progress in understanding VTE risk factors in pregnant women, and available reserves in identifying new risk factors during pregnancy and puerperium in order to stratify risks more efficiently.

Renal transplantation experience in a patient with factor V Leiden homozygous, MTHFR C677T heterozygous, and PAI heterozygous mutation

Vascular complications are important causes of allograft loss in renal transplantation. A two and a half-month-old boy was diagnosed with posterior urethral valve and progressed to end-stage renal disease at eight yr of age. During the HD period, a central venous catheter was replaced three times for repeated thrombosis. The boy was found to be homozygous for FVL and heterozygous for both MTHFR (C677T) and PAI. At the age of 12, renal transplantation was performed from a deceased donor. Postoperative anticoagulation therapy was initiated with continuous intravenous administration of heparin at the dose of 10 IU/kg/h. HD was performed for the first three days. By the fourth day of transplantation, his urine output had increased gradually. Heparin infusion was continued for 18 days during hospitalization at the same dosage. Thereafter, he was discharged with LMWH. On the third month after transplantation, his serum creatinine level was 1.1 mg/dL and eGFR was 75.7 mL/min/1.73 m(2). He has still been using LMWH, and his eGFR was 78.7 mL/min/1.73 m(2) eight months after transplantation. Postoperative low-dose heparin treatment is a safe strategy for managing a patient with multiple thrombotic risk factors.

Risk of Budd-Chiari syndrome associated with factor V Leiden and G20210A prothrombin mutation: a meta-analysis

Background

Various studies have demonstrated that factor V Leiden (FVL) and G20210A prothrombin mutation contribute to the risk of Budd-Chiari syndrome (BCS), while other studies provided conflicting findings. In order to derive more precise estimations of the relationships, a meta-analysis was performed.

Methods

Eligible articles were identified through search of databases including Pubmed, Chinese Biomedical Database (CBM, Chinese), and Chinese National Knowledge Infrastructure (CNKI, Chinese). Odd ratios (ORs) with 95% confidence intervals (CIs) were calculated using random- or fixed- model.

Results

Finally, twelve studies were included for FVL and nine studies were included for G20210A prothrombin mutation. With respect to FVL, significantly increased BCS risk was found in the overall population (OR = 6.29, 95%CI = 4.23–9.36). Subgroup analyses suggested that FVL was associated with an increased risk of BCS in the population with high background mutation prevalence (>1% in the normal population). No significant association was found between BCS and G20210A prothrombin mutation (OR = 1.78, 95%CI = 0.77–4.11).

Conclusion

The presence of FVL should be evaluated in patients with BCS. Conversely, G20210A prothrombin mutation is not significantly associated with risk of BCS. Large-scale well designed studies are necessary to be conducted to further confirm or refute the observed association.