Protein Z, a protein seeking a pathology

2008 ◽  
Vol 100 (10) ◽  
pp. 548-556 ◽  
Author(s):  
Marc Vasse

SummaryProtein Z (PZ) is a vitamin K-dependent factor identified in human plasma in 1984 characterized by an homology with other vitamin K-dependent factors (factor VII, IX, X, protein C). In contrast to these factors, PZ does not possess any enzymatic activity but is involved as a cofactor in the down-regulation of coagulation by forming a complex with the protein Z-dependent protease inhibitor (ZPI). ZPI inhibits the activated factor X (FXa) on phospholipid surface. In mice, the disruption of PZ gene is asymptomatic, but the association with the factor V Leiden mutation leads to a quasi complete mortality during the neonatal period with microvascular thrombosis. In humans, PZ is characterized by an unusual wide distribution in plasma, and a major decrease induced by warfarin. Isolated PZ deficiency does not seem to constitute a risk for venous thrombosis, but a severe PZ deficiency could increase the risk of well recognized venous thrombotic risk factors such as factor V Leiden, G20210A mutation or hyperhomocysteinemia. Unexpectedly, a relationship between PZ deficiency and ischemic arterial diseases such as stroke, acute coronary syndromes or peripheral arterial disease was described but not confirmed by all studies. PZ deficiency could be also a risk factor for early fetal losses, and increases the arterial risk in antiphospholipid syndrome. This review analyzes the different studies so far published and discusses the various results obtained in order to understand whether or not protein Z deficiency could be considered as an arterial ischemic risk factor.

Blood ◽  
2011 ◽  
Vol 118 (8) ◽  
pp. 2055-2061 ◽  
Author(s):  
Elizabeth F. W. van Vlijmen ◽  
Nic J. G. M. Veeger ◽  
Saskia Middeldorp ◽  
Karly Hamulyák ◽  
Martin H. Prins ◽  
...  

AbstractCurrent guidelines discourage combined oral contraceptive (COC) use in women with hereditary thrombophilic defects. However, qualifying all hereditary thrombophilic defects as similarly strong risk factors might be questioned. Recent studies indicate the risk of venous thromboembolism (VTE) of a factor V Leiden mutation as considerably lower than a deficiency of protein C, protein S, or antithrombin. In a retrospective family cohort, the VTE risk during COC use and pregnancy (including postpartum) was assessed in 798 female relatives with or without a heterozygous, double heterozygous, or homozygous factor V Leiden or prothrombin G20210A mutation. Overall, absolute VTE risk in women with no, single, or combined defects was 0.13 (95% confidence interval 0.08-0.21), 0.35 (0.22-0.53), and 0.94 (0.47-1.67) per 100 person-years, while these were 0.19 (0.07-0.41), 0.49 (0.18-1.07), and 0.86 (0.10-3.11) during COC use, and 0.73 (0.30-1.51), 1.97 (0.94-3.63), and 7.65 (3.08-15.76) during pregnancy. COC use and pregnancy were independent risk factors for VTE, with highest risk during pregnancy postpartum, as demonstrated by adjusted hazard ratios of 16.0 (8.0-32.2) versus 2.2 (1.1-4.0) during COC use. Rather than strictly contraindicating COC use, we advocate that detailed counseling on all contraceptive options, including COCs, addressing the associated risks of both VTE and unintended pregnancy, enabling these women to make an informed choice.


2013 ◽  
Vol 109 (05) ◽  
pp. 878-884 ◽  
Author(s):  
Chuangye He ◽  
Zhanxin Yin ◽  
Jing Niu ◽  
Ming Bai ◽  
Zhiping Yang ◽  
...  

SummaryIn Western countries, thrombotic risk factors for Budd-Chiari syndrome (BCS) are very common, including factor V Leiden mutation, prothrombin G20210A mutation, myeloproliferative neoplasms, paroxysmal nocturnal haemoglobinuria, etc. However, the data regarding thrombotic risk factors in Chinese BCS patients are extremely limited. An observational study was conducted to examine this issue. A total of 246 BCS patients who were consecutively admitted to our department between July 1999 and December 2011 were invited to be examined for thrombotic risk factors. Of these, 169 patients were enrolled. Neither factor V Leiden mutation nor prothrombin G20210A mutation was found in any of 136 patients tested. JAK2 V617F mutation was positive in four of 169 patients tested. Neither MPL W515L/K mutation nor JAK2 exon 12 mutation was found in any of 135 patients tested. Overt myeloproliferative neoplasms were diagnosed in five patients (polycythemia vera, n=3; essential thrombocythemia, n=1; idiopathic myelofibrosis, n=1). Two of them had positive JAK2 V617F mutation. Both CD55 and CD59 deficiencies were found in one of 166 patients tested. This patient had a previous history of paroxysmal nocturnal haemoglobinuria before BCS. Anticardiolipin IgG antibodies were positive or weakly positive in six of 166 patients tested. Hyperhomocysteinaemia was found in 64 of 128 patients tested. 5,10-methylenetetrahydrofolate reductase C677T mutation was found in 96 of 135 patients tested. In conclusion, factor V Leiden mutation, prothrombin G20210A mutation, myeloproliferative neoplasms, and paroxysmal nocturnal haemoglobinuria are very rare in Chinese BCS patients, suggesting that the etiological distribution of BCS might be different between Western countries and China.


VASA ◽  
2015 ◽  
Vol 44 (4) ◽  
pp. 313-323 ◽  
Author(s):  
Lea Weingarz ◽  
Marc Schindewolf ◽  
Jan Schwonberg ◽  
Carola Hecking ◽  
Zsuzsanna Wolf ◽  
...  

Abstract. Background: Whether screening for thrombophilia is useful for patients after a first episode of venous thromboembolism (VTE) is a controversial issue. However, the impact of thrombophilia on the risk of recurrence may vary depending on the patient’s age at the time of the first VTE. Patients and methods: Of 1221 VTE patients (42 % males) registered in the MAISTHRO (MAin-ISar-THROmbosis) registry, 261 experienced VTE recurrence during a 5-year follow-up after the discontinuation of anticoagulant therapy. Results: Thrombophilia was more common among patients with VTE recurrence than those without (58.6 % vs. 50.3 %; p = 0.017). Stratifying patients by the age at the time of their initial VTE, Cox proportional hazards analyses adjusted for age, sex and the presence or absence of established risk factors revealed a heterozygous prothrombin (PT) G20210A mutation (hazard ratio (HR) 2.65; 95 %-confidence interval (CI) 1.71 - 4.12; p < 0.001), homozygosity/double heterozygosity for the factor V Leiden and/or PT mutation (HR 2.35; 95 %-CI 1.09 - 5.07, p = 0.030), and an antithrombin deficiency (HR 2.12; 95 %-CI 1.12 - 4.10; p = 0.021) to predict recurrent VTE in patients aged 40 years or older, whereas lupus anticoagulants (HR 3.05; 95%-CI 1.40 - 6.66; p = 0.005) increased the risk of recurrence in younger patients. Subgroup analyses revealed an increased risk of recurrence for a heterozygous factor V Leiden mutation only in young females without hormonal treatment whereas the predictive value of a heterozygous PT mutation was restricted to males over the age of 40 years. Conclusions: Our data do not support a preference of younger patients for thrombophilia testing after a first venous thromboembolic event.


1996 ◽  
Vol 75 (03) ◽  
pp. 422-426 ◽  
Author(s):  
Paolo Simioni ◽  
Alberta Scudeller ◽  
Paolo Radossi ◽  
Sabrina Gavasso ◽  
Bruno Girolami ◽  
...  

SummaryTwo unrelated patients belonging to two Italian kindreds with a history of thrombotic manifestations were found to have a double heterozygous defect of factor V (F. V), namely type I quantitative F. V defect and F. V Leiden mutation. Although DNA analysis confirmed the presence of a heterozygous F. V Leiden mutation, the measurement of the responsiveness of patients plasma to addition of activated protein C (APC) gave results similar to those found in homozygous defects. It has been recently reported in a preliminary form that the coinheritance of heterozygous F. V Leiden mutation and type I quantitative F. V deficiency in three individuals belonging to the same family resulted in the so-called pseudo homozygous APC resistance with APC sensitivity ratio (APC-SR) typical of homozygous F. V Leiden mutation. In this study we report two new cases of pseudo homozygous APC resistance. Both patients experienced thrombotic manifestations. It is likely that the absence of normal F. V, instead of protecting from thrombotic risk due to heterozygous F. V Leiden mutation, increased the predisposition to thrombosis since the patients became, in fact, pseudo-homozygotes for APC resistance. DNA-analysis is the only way to genotype a patient and is strongly recommended to confirm a diagnosis of homozygous F. V Leiden mutation also in patients with the lowest values of APC-SR. It is to be hoped that no patient gets a diagnosis of homozygous F. V Leiden mutation based on the APC-resi-stance test, especially when the basal clotting tests, i.e., PT and aPTT; are borderline or slightly prolonged.


2006 ◽  
Vol 21 (1) ◽  
pp. 24-27 ◽  
Author(s):  
A Mansilha ◽  
F Araújo ◽  
M Severo ◽  
S M Sampaio ◽  
T Toledo ◽  
...  

Objective: To evaluate the association between the Factor V Leiden (FV R506Q) and prothrombin gene (FII G20210A) mutations and deep venous thrombosis (DVT) in young people. Methods: Blood samples were drawn from 199 subjects: 100 healthy controls and 99 unselected patients, with an objectively documented first episode of DVT under 40 years old. DNA analysis was performed using the polymerase chain reaction. Results: The mean age in the patient cohort was 27 years (range 16–40) and 68 (68.7%) were women. Patient prevalences were 20.6% and 10.1% for FV R506Q and FII G20210A, respectively. In the control group, carrier frequencies were 2% and 5%, respectively. We found an increased overall relative risk of DVT with statistical significance for FV R506Q carriers (OR: 12.8; 95% CI: 2.9–56.7; P < 0.001), but not for FII G20210A mutation (OR: 2.1; 95% CI: 0.7–6.5; P = 0.19). Conclusions: Our results suggest a possible increase in DVT risk for the young G20210A allele carriers, which can be more expressed in the presence of a circumstantial risk factor. There is extremely strong evidence that the Factor V Leiden mutation is an important risk factor in the development of a first episode of DVT in young people.


2013 ◽  
Vol 24 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Ivonne Wieland ◽  
Thomas Jack ◽  
Kathrin Seidemann ◽  
Martin Boehne ◽  
Florian Schmidt ◽  
...  

AbstractArterial thrombosis in neonates and children is a rare event and is often associated with external risk factors such as asphyxia or sepsis. We report our experiences with two neonates with spontaneous aortic arch thrombosis mimicking aortic coarctation. Despite single case reports until now, no data exist for the underlying thrombophilic risk factors and prognosis of this rare event. Both patients were carriers of a heterozygous factor V Leiden mutation, which has been reported once before as a risk factor for aortic arch thrombosis. One of our patients was operated upon successfully and is alive. The second patient suffered a large infarction of the right medial cerebral artery and had a thrombotic occlusion of the inferior caval vein. The patient obtained palliative care and died at the age of 6 days. In the literature, we identified 19 patients with neonatal aortic arch thrombosis. Of the 19 patients, 11 (58%) died. Including the two reported patients, the mortality rate of patients with multiple thromboses was 80% (8/10) compared with 18% (2/11) for patients with isolated aortic arch thrombosis; this difference reached statistical significance (p = 0.009). The analysis of thrombophilic disorders revealed that factor V Leiden mutation and protein C deficiency seem to be the most common risk factors for aortic arch thrombosis.Conclusion:Neonatal aortic arch thrombosis is a very rare but life-threatening event, with a high rate of mortality, especially if additional thrombotic complications are present. Factor V Leiden mutation seems to be one important risk factor in the pathogenesis of this fatal disease.


1998 ◽  
Vol 55 (8) ◽  
pp. 1137 ◽  
Author(s):  
James F. Meschia ◽  
José Biller ◽  
Thomas Witt ◽  
Anne Greist ◽  
Steve N. Rhinehart

Blood ◽  
2003 ◽  
Vol 102 (5) ◽  
pp. 1686-1692 ◽  
Author(s):  
Rory R. Koenen ◽  
Guido Tans ◽  
René van Oerle ◽  
Karly Hamulyák ◽  
Jan Rosing ◽  
...  

AbstractProtein S exhibits anticoagulant activity independent of activated protein C (APC). An automated factor Xa–based one-stage clotting assay was developed that enables quantification of the APC-independent activity of protein S in plasma from the ratio of clotting times (protein S ratio [pSR]) determined in the absence and presence of neutralizing antibodies against protein S. The pSR was 1.62 ± 0.16 (mean ± SD) in a healthy population (n = 60), independent of plasma levels of factors V, VIII, IX, and X; protein C; and antithrombin, and not affected by the presence of factor V Leiden. The pSR strongly correlates with the plasma level of protein S and is modulated by the plasma prothrombin concentration. In a group of 16 heterozygous protein S–deficient patients, the observed mean pSR (1.31 ± 0.09) was significantly lower than the mean pSR of the healthy population, as was the pSR of plasma from carriers of the prothrombin G20210A mutation (1.47 ± 0.21; n = 46). We propose that the decreased APC-independent anticoagulant activity of protein S in plasma with elevated prothrombin levels may contribute to the thrombotic risk associated with the prothrombin G20210A mutation.


Sign in / Sign up

Export Citation Format

Share Document