scholarly journals A nonsense polymorphism in the protein Z-dependent protease inhibitor increases the risk for venous thrombosis

Blood ◽  
2006 ◽  
Vol 108 (1) ◽  
pp. 177-183 ◽  
Author(s):  
Javier Corral ◽  
Rocio González-Conejero ◽  
Jose Manuel Soria ◽  
Jose Ramón González-Porras ◽  
Elena Pérez-Ceballos ◽  
...  
Keyword(s):  
Protease Inhibitor ◽  
Venous Thrombosis ◽  
Stop Codon ◽  
Anticoagulant Activity ◽  
Low Frequency ◽  
Protein Z ◽  
Antithrombin Deficiency ◽  
Thrombotic Risk ◽  
Genetic Modifications ◽  
History Of

The protein Z-dependent protease inhibitor (ZPI) is a hemostatic serpin with anticoagulant activity. As for antithrombin, deficiency of ZPI could have relevant thrombotic consequences. We have studied 6 genetic modifications affecting the ZPI gene, identifying 5 haplotypes. Haplotype H5 is featured by a stop codon at position 67. The relevance of these genetic modifications and haplotypes in venous thrombosis was evaluated in a case-control study including 1018 patients and 1018 age- and sex-matched controls. Surprisingly, the H5 haplotype was found in 0.9% of controls, supporting that the Arg67Stop change is a low frequency nonsense polymorphism. The prevalence of this haplotype increased significantly in patients (3.0%), one of whom was in a homozygous state. Multivariate analysis confirms that carriers have a 3.3-fold risk of developing venous thrombosis (P = .002; 95% CI: 1.5-7.1). Moreover, we observed a significant association of this polymorphism with familial history of thrombosis (P < .001). Our study supports that the ZPI Arg67Stop nonsense polymorphism might be an independent genetic risk factor for venous thrombosis. This polymorphism has slightly lower prevalence but similar thrombotic risk than the FV Leiden or prothrombin 20210A. Although further studies are required, all available data support that the ZPI is a candidate to play a significant role in thrombosis and should be evaluated in thrombophilic studies. (Blood. 2006;108:177-183)

Mutations within the Protein Z-Dependent Protease Inhibitor (ZPI) Gene Are Associated with Venous Thromboembolic Disease: A New Form of Thrombophilia.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 488-488 ◽  
Author(s):  
Paul L. Harper ◽  
Neil S. Van de Water ◽  
Fern Ashton ◽  
Tina Tan ◽  
Anne O Grady ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Stop Codon ◽  
Mutation Screening ◽  
Heteroduplex Analysis ◽  
Power Calculation ◽  
Coding Region ◽  
Protein Z ◽  
Stop Codons ◽  
Pcr Products ◽  
New Form

Abstract ZPI is a recently characterised inhibitory serpin present in plasma. In vitro studies have shown that ZPI inhibits both factor Xa (in the presence of protein Z) and factor XIa. Deficiency of ZPI is predicted to enhance coagulation and may be a risk factor for venous thrombosis. To test this hypothesis we carried out mutation screening within the coding region of the ZPI gene in a cohort of 150 patients with a history of DVT or PE (first event before the age of 60 years) and 150 matched controls. Five PCR products were produced for each subject. Heteroduplex analysis was performed using dHPLC and the PCR products were sequenced directly if a heteroduplex mismatch was identified. Sixteen mutations/polymorphisms were identified within the coding region of the ZPI gene. Two mutations were regarded as functionally significant as they produced stop codons at arginine 67 and tryptophan 303 and would be expected to result in the loss of ZPI activity. These stop codon mutations were found in 8 patients and 2 controls. Based on these results, a power calculation was performed that showed that an additional 100 patients and controls would be necessary to confirm that the stop codon mutations were statistically significant risk factors for thrombosis. Bidirectional allele specific PCR was developed to rapidly identify these stop codon mutations and a further 100 patients and 100 controls were examined using this technique. The stop codon mutations were found in 11 patients (W303X n=8: R67X n=3) and only 2 controls (R67X n=2) (two sided Fishers exact p=0.02) with an odds ratio = 5.7 (95%CI, 1.25 to 26.0). In addition two further non-conservative mutations were identified in two other thrombosis patients. These resulted in a serine to tyrosine (codon 122) and a phenylalanine to leucine (codon 124) change in the region homologous to the D helix of other heparin activated serpins. These changes, involving bulky aromatic amino acid residues, have the potential to disrupt the structure and function of the D helix. We identified a further 12 mutations/polymorphisms (C454G, C574T, A603G, A647G, G752A, A947T, C1276T, G1277A, G1438A, A1617C, G1789T and C1811T (italics: not previously described)). The significance of these mutations is uncertain. We have identified mutations causing stop codons, which will result in loss of ZPI function, in 4.4% of patients who present with venous thrombosis before the age of 60 years, compared with an incidence of only 0.8% in controls. Further studies are ongoing to measure the plasma concentration of ZPI in the affected individuals. Our results support an association between mutations in the ZPI gene and venous thrombosis. We propose that ZPI deficiency as a result of these mutations is potentially a new form of thrombophilia.

The risk of venous thrombosis in individuals with a history of superficial vein thrombosis and acquired venous thrombotic risk factors

Blood ◽  
2013 ◽  
Vol 122 (26) ◽  
pp. 4264-4269 ◽  
Author(s):  
Rachel E. J. Roach ◽  
Willem M. Lijfering ◽  
Astrid van Hylckama Vlieg ◽  
Frans M. Helmerhorst ◽  
Frits R. Rosendaal ◽  
...  
Keyword(s):  
Risk Factors ◽  
Risk Factor ◽  
Venous Thrombosis ◽  
Superficial Vein ◽  
Thrombotic Risk ◽  
Vein Thrombosis ◽  
Thrombotic Risk Factor ◽  
Key Points ◽  
Superficial Vein Thrombosis ◽  
History Of

Key Points Superficial vein thrombosis combined with an acquired thrombotic risk factor increases the risk of venous thrombosis 10- to 100-fold. If confirmed, these findings have important implications for the future prevention of venous thrombosis.

Protein Z Levels Could Help To Predict Obstetrical Complications and Arterial Thrombosis in Patients with Antiphospholipid Antibodies.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4081-4081
Author(s):  
Annick Ankri ◽  
Isabelle Martin-Toutain ◽  
Kiarach Goldar ◽  
Marie-Claude Diemert ◽  
Danielle Vauthier-Brouze ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Plasma Protein ◽  
Plasma Levels ◽  
Antiphospholipid Antibodies ◽  
Arterial Thrombosis ◽  
Clinical Event ◽  
Protein Z ◽  
Thrombotic Risk ◽  
Obstetrical Complications ◽  
Thrombotic Tendency

Abstract Introduction: Protein Z (PZ) is a vitamin K dependant plasma protein synthesized by the liver. The precise physiological function of PZ is still unclear: - anticoagulant, the PZ-dependant protease inhibitor complex inhibits factor Xa and acts as a naturally occurring anticoagulant; - procoagulant, PZ promote the assembly of thrombin with PL vesicles- and promote coagulation. In clinical situations, low PZ plasma levels have been associated with bleeding and thrombotic tendency while elevated PZ plasma levels have been linked with ischemic stroke. Antiphospholipid syndrome (APS) is a complex autoimmune thrombotic disorder. Despite specific clinical and laboratory criteria, diagnostic and prognostic tools in patients with APS are limited in their ability to predict adverse outcome in patients with antiphospholipid antibodies (aPLA). Therefore, we hypothesized that PZ could play a role in the thrombotic tendency. Study: to evaluate our hypothesis, we measured PZ plasma concentrations in a case control study including 61 patients with confirmed aPLA with or without APS versus 53 controls. Among the group of patients with APS, 15 had obstetrical complications (OC), 16 had arterial thrombosis (AT) and 11 venous thrombosis (VT). Nineteen patients had aPLA without APS defining the APS(−) group. Plasma PZ antigen concentrations were measured on citrated plasma using the commercial ELISA kit, Asserachrom protein Z, (Diagnostica Stago). Results: PZ plasma levels were normally distributed. Normal PZ concentrations defined as mean ±2 SD were contained between 0.4 and 2.6 μg/mL. No difference was found in mean+ SD between male and female. Two per cents of controls and 18% of patients with venous thrombosis had PZ under 0.4 μg/mL. Forty per cents of patients with OC, 25% with AT and 18% with VT had PZ above 2.6 μg/mL. Plasma protein Z levels measured at least 6 month after any clinical event were significantly higher in APS patients than in controls and APS(−) patients [mean ± SD μg/mL, 2.0 ± 0.9 vs 1.5 ± 0.5 and 1.3 ± 0.5 respectively). According to the clinical complications, PZ concentrations were significantly greater in the group with OC (2.4+0.6 μg/mL) and AT (2.05+0.8 μg/mL) than in controls (1.5+0.5 μg/mL), VT(1.3+0.9 μg/mL) and APS(−) (1.3+0.5 μg/mL) patients [OC vs Controls: p<0.0001; AT vs Controls: p= 0.0047; OC vs AT: p= NS; OC vs APS(−):p< 0.0001; OC vs VT: p= 0.0016, APS(−) vs controls: NS; APS(−) vs VT: NS; VT vs Controls: NS; APS(−) vs AT: p=0.0034; AT vs VT: p= 0.05]. We found an increased relative risk of OC and AT with increasing PZ levels with odds ratios of 7.1 [95% CI: 2.1–23.7] for OC and 2.4 [95% CI: 1.1–5.4] for AT. Conclusion: our study retrospective on a small size sample, indicates that high protein Z plasma could be a high risk for obstetrical complications and a lower risk for arterial thrombosis in aPLA patients. Measure of PZ could help to evaluate obstetrical and thrombotic risk of patients with aPLA. Further prospective studies are needed to confirm our results.

Two missense mutations identified in venous thrombosis patients impair the inhibitory function of the protein Z dependent protease inhibitor

2012 ◽  
Vol 107 (05) ◽  
pp. 854-863 ◽  
Author(s):  
Nigel P. Birch ◽  
Peter J. Browett ◽  
Paul B. Coughlin ◽  
Anita J. Horvath ◽  
Neil S. Van de Water ◽  
...  
Keyword(s):  
Protease Inhibitor ◽  
Venous Thrombosis ◽  
Nonsense Mutation ◽  
Healthy Controls ◽  
Missense Mutations ◽  
Wild Type ◽  
Protein Z ◽  
Inhibitory Function

SummaryProtein Z-dependent protease inhibitor (ZPI) is a plasma inhibitor of factor (F)Xa and FXIa. In an earlier study, five mutations were identified within the ZPI gene of venous thrombosis patients and healthy controls. Two of these were nonsense mutations and three were missense mutations in important regions of the protein. Here we report that two of these latter three mutations, F145L and Q384R, impair the inhibitory function of ZPI in vitro. Recombinant wild-type and mutant proteins were prepared; stability in response to thermal challenge was similar. Inhibition of FXa in the presence of the cofactor protein Z was reduced 68-fold by the Q384R mutant; inhibition of FXIa by the F145L mutant was reduced two- to three-fold compared to the wild-type ZPI. An analysis of all five ZPI mutations was undertaken in a cohort of venous thrombosis patients (n=550) compared to healthy controls (n=600). Overall, there was a modest increase in incidence of these mutations in the thrombosis group (odds ratio 2.0, 1.05–3.7, p=0.044). However, in contrast to W324X (nonsense mutation), the Q384R missense mutation and R88X nonsense mutation were evenly distributed in patients and controls; F145L was rare. The final mutation (S143Y) was also rare and did not significantly alter ZPI function in laboratory studies. The F145L and particularly the Q384R mutation impaired the function of the coagulation inhibitor ZPI; however, there was no convincing association between these mutations and venous thrombosis risk. The functional role for ZPI in vivo has yet to be clarified.

scholarly journals Protein Z–dependent protease inhibitor deficiency produces a more severe murine phenotype than protein Z deficiency

Blood ◽  
2008 ◽  
Vol 111 (10) ◽  
pp. 4973-4978 ◽  
Author(s):  
Jing Zhang ◽  
Yizheng Tu ◽  
Lan Lu ◽  
Nina Lasky ◽  
George J. Broze
Keyword(s):  
Protease Inhibitor ◽  
Factor Xa ◽  
Coagulation Factor ◽  
Plasma Vitamin ◽  
Severe Phenotype ◽  
Epinephrine Infusion ◽  
Protein Z ◽  
Thrombotic Risk ◽  
Factor Xia

Abstract Protein Z (PZ) is a plasma vitamin K–dependent protein that functions as a cofactor to dramatically enhance the inhibition of coagulation factor Xa by the serpin, protein Z–dependent protease inhibitor (ZPI). In vitro, ZPI not only inhibits factor Xa in a calcium ion–, phospholipid-, and PZ-dependent fashion, but also directly inhibits coagulation factor XIa. In murine gene-deletion models, PZ and ZPI deficiency enhances thrombosis following arterial injury and increases mortality from pulmonary thromboembolism following collagen/epinephrine infusion. On a factor VLeiden genetic background, ZPI deficiency produces a significantly more severe phenotype than PZ deficiency, implying that factor XIa inhibition by ZPI is physiologically relevant. The studies in mice suggest that human PZ and ZPI deficiency would be associated with a modest thrombotic risk with ZPI deficiency producing a more severe phenotype.

scholarly journals JAK2V617F Variant Allele Frequency Identifies Patients with Polycythemia Vera (PV) at High Risk for Venous Thrombosis

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1776-1776
Author(s):  
Paola Guglielmelli ◽  
Giacomo Coltro ◽  
Giuseppe Gaetano Loscocco ◽  
Benedetta Sordi ◽  
Francesco Mannelli ◽  
...  
Keyword(s):  
Risk Factors ◽  
High Risk ◽  
Venous Thrombosis ◽  
Allele Frequency ◽  
Variant Allele ◽  
Continuous Variables ◽  
Variant Allele Frequency ◽  
Thrombotic Risk ◽  
History Of ◽  
The Impact

Abstract Background. Cardiovascular (CV) events are leading cause of morbidity and mortality in PV. Current risk stratification is based on variables predicting thrombotic risk, ie age >60y and history of thrombosis. Recent studies focused on additional thrombotic risk factors in PV, including generic CV factors and leukocytosis. PV patients (pts) are JAK2V617F mutated, and present wide heterogeneity in variant allele frequency (VAF); it was shown that a VAF >75% was associated with higher number of thrombotic events after diagnosis (Vannucchi AM, Leukemia 2007), but the prognostic role of JAK2 VAF is still debated. Aim. The aim of the study was to evaluate the impact of JAK2V617F VAF on rate of thrombosis in WHO-2016 defined PV pts. Patients and Method. In the CRIMM (Florence) database, a total of 577 pts with a JAK2VF VAF determined within 3 years from diagnosis, who met the 2016 WHO criteria for PV, were identified. All pts had information regarding thromboembolic events, including history of thrombosis, occurrence, type and date of thrombosis in the follow-up (FU) and presence of CV risk factors (smoking, hypertension, and diabetes mellitus). Thrombosis‐free survival (TFS) was determined from the time of diagnosis to the time the first thrombotic event occurred. Pts in whom thrombosis did not occur were censored at the time of last FU. Pre-receiver operating characteristic (ROC) plots were used to determine cutoff levels for continuous variables of interest. Differences in the distribution of continuous variables between categories were analyzed by Mann-Whitney or Kruskal-Wallis test. Pts' groups with nominal variables were compared by χ2 test. TFS was estimated by Kaplan Meier analysis; log rank test was used to compare TFS difference between groups. Cox proportional hazards regression was used for multivariable analysis. A two tailed P ≤ 0.05 was considered statistically significant. Results. The median age of pts at diagnosis was 61y, 308 (53.4%) were above 60y; 57.2% were males. All pts were mutated for JAK2V617F with a median VAF 43% (range 1-100%), 62% had at least one CV risk factor; 83 (14.4%) pts suffered from an episode of thrombosis within 3 yr from, or coincident with, diagnosis. The median FU was 7.3y (0.6-35.9y) during which 87 pts (15.1%) developed thrombosis. (50 arterial and 45 venous thrombosis). During the FU, 110 pts (19.1%) died. A JAK2VAF of ≥60% cutoff level, as determined by ROC analysis, correlated with measurements of stimulated erythropoiesis (higher hematocrit, lower mean cell volume and serum ferritin; all P<.01), leukocytosis (P<.0001), lower platelets count (P=.02) and elevated serum lactate dehydrogenase (LDH) (P<.03). Pts with ≥60% JAK2V617F VAF were at higher relative risk (RR) of having splenomegaly (RR 3.1; P<0.001), suffering from pruritus (RR 2.5; P<0.001) or constitutional symptoms (RR 1.9; P=0.01), harboring a BM fibrosis grade-1 (RR 3.1; P<0.001). Additionally, pts with a VAF>60% had greater risk to progress to PPV-MF (RR 8.5, P<.0001) and acute leukemia (RR 4.4, P=0.04) or to die (RR 3.8, P<0.0001). The JAK2VF VAF (continuous or ≥60%) did not correlate with occurrence of thrombosis at diagnosis, while the rate of thrombosis during FU was significantly increased in pts with VAF ≥60% (23.4% vs 11.0%, RR 2.4, 95%CI = 1.4-4.0; P<0.0001), more marked for venous (RR 3.7, 95%CI = 2.0-6.8; P<0.0001) than arterial (RR 1.8, 95%CI = 0.9-3.3; P=0.05) thrombosis. The impact of VAF on thrombosis during FU was then estimated according to the conventional risk category. In low risk pts (LR) (n=236), factors significantly associated with occurrence of FU thrombosis were CV risk factors (dyslipidemia (RR 3.3, P = 0.02) and hypertension (RR 1.8, P=0.048)), a G1 BM fibrosis (RR 5.3, P=0.006), presence of splenomegaly (RR, 3.2, P=0.001) or constitutional symptoms (RR 3.3, P=0.003) and a VAF ≥60% (RR 2.2, P = 0.024). In high risk pts (HR) (n=341), factors significant for FU thrombosis were splenomegaly (RR 2.0, P=0.03), elevated LDH (RR 4.0, P=0.009) and a VAF ≥60% (RR 2.3, P = 0.012). A VAF ≥60% was correlated with shortened venous TFS after diagnosis in HR (P = 0.01, HR = 3.2, 95%CI = 1.2−8.3; fig.) but not in LR pts (P = 0.20, HR = 1.1, 95%CI = 0.5−2.9). Conclusions. This study indicates that conventionally-defined high-risk PV pts with a JAK2V617F VAF ≥60% suffer from increased rate of venous events and might be worthwhile of more intensive antithrombotic prophylaxis. Figure. Figure. Disclosures No relevant conflicts of interest to declare.

Venous thrombosis and multiple prothrombotic gene defects

2003 ◽  
Vol 23 (03) ◽  
pp. 117-120
Author(s):  
C. Mengis ◽  
F. Demarmels Biasiutti
Keyword(s):  
Risk Factors ◽  
Venous Thrombosis ◽  
Thrombotic Event ◽  
Prothrombin G20210a ◽  
Thrombotic Risk ◽  
History Of ◽  
Fv Leiden ◽  
Gene Defects

SummaryWe describe the case of a 30-year-old woman with homozygous prothrombin G20210A transition and heterozygous FV Leiden mutation and a history of postpartum venous thrombosis. Despite the high thrombotic risk to be assumed in the presence of this combined thrombophilia our patient suffered her first venous thrombotic event only at the age of 29 years during the puerperium of her first pregnancy. This fact supports the concept of venous thrombosis as a multicausal disease, with interaction of genetic and acquired risk factors. The case presented also stresses the importance of performing complete thrombophilia investigation.

scholarly journals P1251THROMBIN GENERATION ASSAY: A POTENTIAL TOOL TO STRATIFY THROMBOTIC RISK IN HEMODIALYSIS PATIENTS

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Ileana Kalikatzaros ◽  
Massimo Radin ◽  
Irene Cecchi ◽  
Savino Sciascia ◽  
Giacomo Forneris ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Venous Thrombosis ◽  
Thrombin Generation ◽  
Previous History ◽  
International Normalized Ratio ◽  
Vascular Events ◽  
Thrombotic Risk ◽  
Thrombin Generation Assay ◽  
Autoimmune Conditions ◽  
History Of

Abstract Background and Aims Patients with Chronic Kidney Disease (CKD) in hemodialysis (HD) show both high thrombotic and hemorrhagic risks. However, routine laboratory techniques aimed to evaluate haemostasis, i.e. activated prothrombin time (PT) and activated partial thromboplastin time (aPTT), are not sensitive enough to detect mild hypocoagulable or hypercoagulable states in this population. Indeed, these methods evaluate the start-up phase of the coagulation, but omit the amplification stage in which an exponential increase of thrombin generation occurs. Thrombin generation assay (TGA) is a second-level global coagulative test able to evaluate thrombin generation and decay. So far the TGA has never been used for assessing thrombotic risk in HD patients. Method This is a monocentric observational retrospective study conducted at San Giovanni Bosco Hospital and University of Turin, Italy. After chart-reviewing of all patients with CKD in HD, we enrolled: Group A) 100 Patients with CKD in HD, treated or not treated with warfarin Group B) 60 Patients treated with Warfarin with normal kidney function Group C) 60 Healthy Controls Results Compared to healthy donor patients on hemodialysis that were not treated with warfarin had significantly lower tLag (mean tLag 8.2±3.4 vs. 9.7±2.9, p &lt; 0.05), lower tPeak (mean tPeak 14.3±6 vs. 16.2±4.7, p &lt; 0.05), lower Peak (mean Peak 151.8±77.4 vs. 209.2±103.8, p &lt; 0.001) and lower AUC (mean AUC 1624.5±564.4 vs. 2023±489.2, p &lt; 0.001) (Figure 1). Compared to controls with normal renal function treated with warfarin, HD patients treated with warfarin had higher tLag (mean tLag 10.5±3.3 vs. 8.3±2.1, p &lt; 0.05), higher tPeak (mean tPeak 16.5±4.9 vs. 13±2.9, p &lt; 0.05). Among HD patients who were not treated with warfarin, those with autoimmune conditions showed a pro-thrombotic TGA profile when compared to HD patients without autoimmune diseases, with significantly higher Peak (mean Peak 188.4±30 vs. 149.9±78.7, p &lt; 0.05) and higher AUC (mean AUC 2066.9±138.2 vs. 1601.5±569, p &lt; 0.001). Similarly, compared to patients without previous history of vascular events (59), patients with previous ischemic stroke or venous thrombosis (41), had significantly lower tLag (mean tLag 8±2.9 vs. 14.2±8.5, p &lt; 0.001), lower tPeak (mean tPeak 14±5.6 vs. 21.7±12.3, p &lt;0.05), higher Peak (mean Peak 154.9±76.8 vs. 71.83±49.2, p&lt;0.05) and higher AUC (mean AUC 1653.7±548.7 vs. 863.4±501.4, p &lt; 0.05). Of note, a significant positive relationship was detected between the International Normalized Ratio (INR) and both tLag (Pearson 0.46, p &lt;0.001) and tPeak (Pearson 0.35, p &lt;0.001). INR was inversely correlated to Peak (Pearson -0.47, p &lt;0.001) and AUC (Pearson -0.61, p &lt;0.001) (Figure 2). Conclusion Identifying patients at high risk for cardiovascular diseases and thrombosis has an important impact on the management of patients with CKD in HD. In this study, we observed a prothrombotic TGA profile in patients with CKD in HD, especially those with autoimmune conditions or previous history of arterial events (especially ischemic stroke) or venous thrombosis. Prospective studies are needed to evaluate the possible clinical use of TGA as thrombotic risk stratification tool in HD patients.

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