The Silence Speaks, but We Do Not Listen: Synonymous c.1824C>T Gene Variant in the Last Exon of the Prothrombin Gene as a New Prothrombotic Risk Factor.

BACKGROUND: Thrombosis is a major global disease burden with almost 60% of cases related to underlying heredity and most cases still idiopathic. Synonymous single nucleotide polymorphisms (sSNPs) are considered silent and phenotypically neutral. Our previous study revealed a novel synonymous FII c.1824C>T variant as a potential risk factor for pregnancy loss, but it has not yet been associated with thrombotic diseases. METHODS: To determine the frequency of the FII c.1824C>T variant we have sequenced patients' DNA. Prothrombin RNA expression was measured by quantitative PCR. Functional analyses included routine hemostasis tests, western blotting and ELISA to determine prothrombin levels in plasma, and global hemostasis assays for thrombin and fibrin generation in carriers of the FII c.1824C>T variant. Scanning electron microscopy was used to examine the structure of fibrin clots. RESULTS: Frequency of the FII c.1824C>T variant was significantly increased in patients with venous thromboembolism and cerebrovascular insult. Examination in vitro demonstrated increased expression of prothrombin mRNA in FII c.1824T transfected cells. Our ex vivo study of FII c.1824C>T carriers showed that the presence of this variant was associated with hyperprothrombinemia, hypofibrinolysis, and formation of densely packed fibrin clots resistant to fibrinolysis. CONCLUSION: Our data indicate that FII c.1824C>T, although a synonymous variant, leads to the development of a prothrombotic phenotype and could represent a new prothrombotic risk factor. As a silent variant, FII c.1824C>T would probably be overlooked during genetic screening, and our results show that it could not be detected in routine laboratory tests.

Long-term safety and efficacy of turoctocog alfa in prophylaxis and treatment of bleeding episodes in severe haemophilia A: Final results from the guardian 2 extension trial.

INTRODUCTION: Turoctocog alfa is a recombinant factor VIII (FVIII) molecule, approved for treatment and prophylaxis of bleeding in patients with haemophilia A. In the guardian 1 (adolescents/adults) and guardian 3 (children) phase 3 trials, turoctocog alfa demonstrated a favourable efficacy and safety profile. Guardian 1 or 3 completers could enrol in the guardian 2 extension. Final guardian 2 results are reported here. AIM: Investigate long-term safety and efficacy of turoctocog alfa administered for prophylaxis and treatment of bleeds. METHODS: In this phase 3b open-label trial, previously treated males of all ages with severe haemophilia A received prophylaxis regimens of turoctocog alfa or on-demand treatment of bleeds. The primary safety endpoint was frequency of FVIII inhibitor development. Efficacy endpoints included annualized bleeding rate (ABR) during prophylaxis, haemostatic response in treatment of bleeds and number of injections required to treat bleeds. RESULTS: Overall, 213 patients were dosed with turoctocog alfa; 207 patients received prophylaxis; 19 received on-demand treatment. No FVIII inhibitors (≥0.6 BU) were reported. For all patients on prophylaxis, overall median ABR was 1.37 bleeds/y; success rate for treatment of bleeds was 90.2%; and 88.2% of bleeds were controlled with 1-2 injections of turoctocog alfa. For the on-demand regimen, overall median ABR was 30.44 bleeds/y; success rate for treatment of bleeds was 96.7%; and 94.9% of bleeds were controlled with 1-2 injections of turoctocog alfa. CONCLUSION: Extended use of turoctocog alfa is safe and effective for prevention and treatment of bleeding episodes in previously treated patients with haemophilia A across all ages.

Complex haemostatic abnormalities as a cause of bleeding after neurosurgery in a patient with Gaucher disease.

We report a treatment-naïve patient with Gaucher disease (GD) who experienced repeated bleeding after three neurosurgeries for a brain tumour, identified as an oligoastrocytoma. The patient had normal values on basic haemostatic tests: prothrombin time, 75-105%; activated partial thromboplastin time, 30.3-34 s; and mild thrombocytopaenia, 96-115 × 10(9 )cells/l. However, additional tests showed mild von Willebrand factor (vWF) deficiency (vWF antigen, 56%; vWF ristocetin cofactor, 49%; factor VIII [FVIII], 54%) and abnormal collagen-mediated platelet aggregation (0.45-0.55). Bleeding control was achieved after vWF/FVIII concentrate and platelet transfusions. This case raises questions about the safe platelet count and basic haemostatic tests for assessing bleeding risk in patients with GD prior to surgery. In patients with GD, a minimum haemostatic evaluation should include platelet count and basic haemostatic tests such as fibrinogen, prothrombin time, activated partial thromboplastin time as well as platelet function tests and assessing vWF and FVIII levels. Specific coagulation factors or platelet function deficiencies should be corrected with factor concentrates or platelet transfusions.

Acquired von Willebrand syndrome in patients with Gaucher disease.

Although various coagulation abnormalities occur in patients with Gaucher disease (GD), von Willebrand factor (vWF) deficiency has rarely been reported. A retrospective review of six treatment naïve cases with GD and concomitant vWF deficiency over a 12-year-period in a single center is presented. All patients had a personal history of prior hemorrhages. Based on both reduced level of vWF antigen (vWF:Ag, range 14-56%) and ristocetin cofactor activity (vWF:RCo, range 12-53%), with a vWF:RCo/Ag ratio >0.7, the diagnosis of type 1 von Willebrand disease was made in all six cases. During enzyme replacement therapy (ERT) of a 2-year duration all patients normalized their vWF:Ag levels. Based on the positive ERT effect on vWF:Ag levels, vWF deficiency was assumed to be acquired. It should be noted that beside vWF deficiency four patients with GD exhibited mild thrombocytopenia (range 81-131×10(9)/L) and three had additional hemostatic defects (reduced collagen platelet aggregation, FV, FXI and FXII deficiencies).

Comparison of two laboratory assays in monitoring the efficacy of different prophylaxis regimens for severe haemophilia.

BACKGROUND: The goal of this study was to compare the validity of two laboratory assays, rotation thromboelastometry (ROTEM) and endogenous thrombin potential (ETP), in monitoring and evaluating different prophylactic treatment regimens in patients with severe haemophilia. METHODS: Twenty adult patients with severe haemophilia were divided into three groups according to treatment regimen with concentrate of factor (F) VIII/IX: full-dose prophylaxis (5 patients), intermediate-dose prophylaxis (5 patients), and on demand treatment (10 patients). RESULTS: The ROTEM for the group treated with full-dose prophylaxis was significantly lower than ROTEM for the group treated with intermediate-dose prophylaxis (p = 0.025). Among the patients given full-dose prophylaxis, 40% (2 patients) had prolonged ROTEM after 3 months of treatment, while among those given intermediate-dose prophylaxis all patients (100%, 5 patients) had prolonged ROTEM (p = 0.038). The ETP was significantly improved after 3 months of full-dose in comparison with intermediate-dose prophylaxis (p = 0.042). CONCLUSIONS: ROTEM and ETP are useful laboratory assays for monitoring efficacy of different prophylaxis regimens with concentrate of FVIII/IX in patients with severe haemophilia, helping in making decisions regarding optimal dose-regimen prophylaxis.

Challenges in the management of women with type 2B von Willebrand disease during pregnancy and the postpartum period: evidence from literature and data from an international registry and physicians' survey-communication from the Scientific and Standardization Committees of the International Society on Thrombosis and Haemostasis.

BACKGROUND: Management of women with type 2B von Willebrand disease (VWD) during pregnancy is challenging because of dysfunctional von Willebrand factor (VWF) and the complexity resulting from discrepant VWF/factor VIII (VWF/FVIII) levels, impaired platelet-dependent VWF activity, progressive thrombocytopenia, and risks associated with the use of desmopressin. There is a lack of high-quality evidence to support clinical decision making. OBJECTIVES: In this study, we examined the current diagnostic and management approaches and outcomes in women with VWD during pregnancy. METHODS: Data were collected via 3 avenues: literature review, an international registry, and an international survey on physicians' practices for the management of pregnancy in women with VWD. The registry and survey were supported by the International Society on Thrombosis and Haemostasis. RESULTS: Data on clinical and laboratory features, management and bleeding complications, and pregnancy outcomes of a total of 55 pregnancies from 49 women across the globe (literature: 35, registry: 20) and data reported by 112 physicians were analyzed. We describe the largest dataset on pregnancies in women with type 2B VWD available to date. The data highlight the following key issues: a) bleeding complications remain a concern in these patients, b) the target safe VWF level and the ideal monitoring approach are unknown, c) there is a wide range of hemostatic management practices in the type and timing of treatment, and d) physicians have diverse views on the mode of delivery and use of neuraxial anesthesia. CONCLUSION: We conclude that an international consensus and guidance are critically required for better care and improved outcomes in this patient cohort.

Corrigendum to 'The Hemophilia Joint Health Score version 2.1 Validation in Adult Patients Study: A multicenter international study' [Research and Practice in Thrombosis and Haemostasis, 6/2, (2022) e12690].

[This corrects the article DOI: 10.1002/rth2.12690.].

Haemostatic abnormalities in treatment-naïve patients with Type 1 Gaucher's disease.

There is a paucity of data on the effects of enzyme replacement therapy (ERT) on the coagulation abnormalities and platelet function of patients with Gaucher's disease (GDPs) and much of this data are controversial. This study investigates the haemostatic parameters in treatment-naïve GDPs and the effects of ERT. 31 Serbian treatment-naïve type 1 GDPs (M/F 17/14; median age 49 years, splenectomized 9/31) were studied. The complete blood count, prothrombin time (PT), activated partial tromboplastin time (aPTT) and coagulation factors were measured using the standard methods. Platelet aggregation was assessed with a whole-blood aggregometer. Splenic volumes were assessed using computer tomography. Twenty-one patients were treated with ERT (Imiglucerase). The haemostatic parameters were assessed after 6, 12 and 24 months (ERT(6, 12, 24)). Initially bleeding episodes were registered in 10/31 GDPs. Median platelet count was 108 × 10(9)/L; 22/31 GDPs were thrombocytopenic. The PT and aPTT values were abnormal in 16/31 and 13/31 GDPs, respectively. Platelet aggregation abnormalities were recorded in 19/31GDPs. Median platelet aggregation was reduced in response to adenosine-diphosphate 5 µmol/L (ADP(5) 0.46) and collagen 5 µmol/L (Col(5) 0.47). Splenic volume inversely correlated with the platelet count and a reduced response to arachidonic acid (AA), Col(5) and ADP(5) (p < 0.05). The splenectomized GDPs had a significantly lower platelet aggregation to Col(10) (p < 0.05). Bleeding GDPs had a significantly lower platelet count, higher chitotriosidase levels and a greater splenic volume compared to non-bleeding patients (p < 0.01). ERT: The number of bleeding GDPs had significantly decreased by ERT(6) (1/10; p < 0.01). The platelet count had significantly increased by ERT(6) (ERT(6) 180 × 10(9)/L, p < 0.01). The PT increased significantly from ERT(0) to ERT(24) (PT(0) 65%, PT(24) 81%; p < 0.05). The von Willebrand factor had increased significantly by ERT(6) and ERT(24) (ERT(0) 56%, ERT(6) 70%, ERT(12) 70%, ERT(24) 86%; p < 0.01). The number of GDPs with abnormal platelet aggregation had decreased significantly by ERT(6) (10/19; p < 0.05). Platelet aggregation on ADP(10) and AA significantly increased by ERT(6) (ADP(10): ERT(0) 0.75, ERT(6) 0.8 p < 0.01; AA: ERT(0) 0.7, ERT(6) 0.8 p < 0.05). In conclusion, platelet dysfunction and coagulation abnormalities were found in a considerable number of our GDPs. The absence of severe bleeding episodes suggests that the haemostatic system is sufficiently balanced and therefore the exact mechanism of the etiology of these abnormalities need to be fully clarified. ERT resulted in the cessation of bleeding and marked increase in platelet count, PT, vWF and platelet aggregation.

Correlation between leukocyte-platelet aggregates and thrombosis in myeloproliferative neoplasms.

INTRODUCTION: The impact of activated blood and endothelial cells on the thrombosis in myeloproliferative neoplasms (MPN) has not yet been clarified. We prospectively analyzed correlation between circulating leukocyte-platelet aggregates and soluble selectins to thrombosis occurrence in MPN, in the context of standard and cardiovascular risk factors, and different clinical and biological characteristics. METHODS: Flow cytometric analysis of neutrophil-platelet (Neu-Plt) and monocyte-platelet (Mo-Plt) aggregates in peripheral blood, as well as quantification of soluble E-/L-/P-selectins by enzyme immunoassay, was performed on 95 newly diagnosed MPN patients. RESULTS: During the follow-up, thrombosis occurred in 12.6% MPN patients (arterial 9.4%, venous 3.2%), with a mean time of 39 months. The overall incidence rate of main thrombotic events was 4.36 per 100 patient-years. The incidence of arterial hypertension (HTA) was significantly higher in patients with thrombosis, compared to those without thrombosis (P < .05). The level of soluble P-selectin was significantly higher in patients with thrombosis compared to those without thrombosis (346.89 ng/mL vs 286.39 ng/mL, P = .034). The mean level of Neu-Plt (26.7% vs 22.4%) and Mo-Plt (17.8% vs 12.3%) aggregates did not differ significantly between the groups with and without thrombosis. A multivariate COX proportional hazard regression model confirmed an independent predictive significance of Mo-Plt aggregates (HR = 1.561, 95% CI: 1.007-2.420, P = .046), as well as the cumulative effect of Mo-Plt aggregates and HTA (HR = 1.975, 95%CI: 1.215-3.212, P = .006) for thrombosis occurrence. CONCLUSION: Monocyte-platelet aggregates represent an independent risk factor for thrombosis occurrence, further on supported by HTA.

Diagnosis and management of severe congenital protein C deficiency (SCPCD): Communication from the SSC of the ISTH.

Severe congenital protein C deficiency (SCPCD) is rare and there is currently substantial variation in the management of this condition. A joint project by three Scientific and Standardization Committees of the ISTH: Plasma Coagulation Inhibitors, Pediatric/Neonatal Thrombosis and Hemostasis, and Women's Health Issues in Thrombosis and Hemostasis, was developed to review the current evidence and help guide on diagnosis and management of SCPCD. We provide a summary of the clinical presentations, differential diagnoses, appropriate investigations to confirm the diagnosis, approaches for management of the acute situation, and options for long-term management including subsequent pregnancies. We finally provide a set of recommendations to help in this regard.

Position Paper on the Management of Pregnancy-Associated Superficial Venous Thrombosis. Balkan Working Group for Prevention and Treatment of Venous Thromboembolism.

Venous thromboembolism (VTE) is a multifactorial disease that can possibly affect any part of venous circulation. The risk of VTE increases by about 2 fold in pregnant women and VTE is one of the major causes of maternal morbidity and mortality. For decades superficial vein thrombosis (SVT) has been considered as benign, self-limiting condition, primarily local event consequently being out of scope of well conducted epidemiological and clinical studies. Recently, the approach on SVT has significantly changed considering that prevalence of lower limb SVT is twice higher than both deep vein thrombosis (DVT) and pulmonary embolism (PE). The clinical severity of SVT largely depends on the localization of thrombosis, when it concerns the major superficial vein vessels of the lower limb and particularly the great saphenous vein. If untreated or inadequately treated, SVT can potentially cause DVT or PE. The purpose of this review is to discuss the complex interconnection between SVT and risk factors in pregnancy and to provide evidence-based considerations, suggestions, and recommendations for the diagnosis and treatment of this precarious and delicate clinical entity.

Incidence of inhibitor development in PUPs with severe Haemophilia A in the CEE region between 2005 and 2015.

INTRODUCTION: This study analyses real-world data on 144 previously untreated patients (PUPs) with severe Haemophilia A, from seven countries in Central and Eastern Europe (CEE: Bulgaria, Croatia, Czech Republic, Hungary, Latvia, Serbia, and Slovenia), over a period of 11 years. It analyses the risk factors associated with development of inhibitors to factor VIII concentrates. METHODS: Cox proportional hazard models were used to estimate the hazard risk of factors possibly influencing the development of inhibitors. Patients were followed for up to 100 exposure days (EDs). RESULTS: Cumulative inhibitor incidence at the time of 100 EDs was 18.7%, slightly lower than the 25-35% incidence reported in most studies. Of PUPs who developed inhibitors, a majority (56%) developed them within the first 20 EDs and 88% by the 50th ED. FVIII class (recombinant or plasma-derived) did not influence the inhibitors' incidence rate (p = 0.64). We found a significant protective effect of prophylaxis compared to on-demand treatment (p = 0.003). PUPs who had an intensive peak treatment during the first 50 EDs were at significantly higher risk for inhibitor development (HR (95% CI) 5.3 (2.3-12.5), p < 0.001). CONCLUSION: Inhibitors are and will continue to be the most significant complication of haemophilia treatment with factor concentrates. This is particularly true for haemophilia A. In our cohort, we were able to show that the treatment regimen used during first 50EDs influenced significantly the inhibitor risk, but the class of the factor concentrate did not play an important role. Real world data will remain one of the important resources for improving our knowledge of haemophilia.

Body Mass Index Best Predicts Recovery of Recombinant Factor VIII in Underweight to Obese Patients with Severe Haemophilia A.

BACKGROUND: Factor VIII (FVIII) products are usually dosed according to body weight (BW). This may lead to under- or over-dosing in underweight or obese patients, respectively. OBJECTIVE: This article evaluates the pharmacokinetics (PK) of recombinant FVIII concentrate, particularly recovery, in relation to body mass index (BMI) and other body composition descriptors. MATERIALS AND METHODS: Thirty-five previously treated adults with severe haemophilia A from five BMI categories (underweight, normal, overweight, obese class I and II/III) were included. PK was evaluated after 50 IU per kilogram of BW single-dose recombinant FVIII (turoctocog alfa). The body composition variable was based on measurements of weight, height, bioimpedance analysis, and dual-energy X-ray absorptiometry. A dosing model was derived to achieve similar peak FVIII activity levels across BMI categories. RESULTS: A statistically significant positive association between BMI and C30min, IR30min, and AUC0-inf was observed; CL and Vss showed a significant negative association with BMI; t½ was independent of BMI and other parameters. The dosing model introduced a correction factor 'M' for each BMI category, based on linear regression analysis of C30min against BMI, which ranged from 0.55 for underweight to 0.39 for obese class II/III. This model achieved similar peak FVIII activity levels across BMI categories, estimating an average dose adjustment of +243.3 IU (underweight) to -1,489.6 IU (obese class II/III) to achieve similar C30min. CONCLUSION: BMI appears to be the best predictor of recombinant FVIII recovery; however, PK endpoints were also dependent on other body composition variables. The model demonstrated that dosing can be adjusted for individual BMI to achieve better FVIII predictability across BMI categories.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy with severe factor XII deficiency.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited adult-onset microangiopathy caused by missense mutations in the Notch3gene on chromosome 19. However, common vascular risk factors may additionally modify clinical expression and progression of the disease. The role of various prothrombotic factors has also been implied. We report a case of a middle-aged man with typical clinical, neuroimaging and histological features of CADASIL, but with notably prolonged activated partial thromboplastin time. Hematological investigations revealed severe clotting Factor XII deficiency. This case illustrates that the occurrence of vascular risk factors should not be overlooked in patients with CADASIL.

The influence of specific mutations in the AT gene (SERPINC1) on the type of pregnancy related complications.

BACKGROUND: Inherited antithrombin (AT) deficiency is a rare autosomal dominant disorder, caused by mutations in the SERPINC1 gene. The most common clinical presentation in AT deficient patients includes venous thrombosis and pulmonary embolism, while the association of AT deficiency and its effect on the development of pregnancy complications has been less studied. The aim of our research was to evaluate the effect of AT deficiency types, determined by genotyping, on pregnancy outcomes. METHODS: A retrospective cohort study included 28 women with AT deficiency, and their 64 pregnancies were analyzed. RESULTS: With regard to live birth rate, a significant difference was observed among women who were carriers of different SERPINC1 mutations, as the rate varied from 100% in cases of type I to the extremely low rate of 8% for women with type II HBS (AT Budapest 3) in the homozygous variant, P = 0.0005. All pregnancies from the type I group, even untreated ones, resulted in live births. In women with AT Budapest 3 in homozygous variant the overall live birth rate increased to 28.5% in the treated pregnancies. In this group the highest incidence of fetal death was observed of 62%; repeated fetal losses in 30%; fetal growth restriction in 22% and placental abruption in 7% of all pregnancies. CONCLUSION: Our study results indicate a difference between type I and type II AT deficiency. The risk of pregnancy related VTE was equally present in both groups, except for AT Budapest 3 in the heterozygous variant, while adverse pregnancy outcomes were strictly related to type II, especially AT Budapest 3 in the homozygous variant.

How do you decide on hormone replacement therapy in women with risk of venous thromboembolism?

Women are increasingly encouraged to participate in making decisions about hormone replacement therapy (HRT). In postmenopausal women with severe vasomotor symptoms, HRT can significantly improve the quality of life. However, the use of HRT may also increase the risk of venous thromboembolism (VTE), the risk which depends of both treatment-related and patient-related factors. This review summarizes some important points about the selection of the safest hormonal replacement modality in women with a history of VTE and management of VTE risks in postmenopausal women wishing to take HRT.

Pregnancy and delivery in a woman with severe haemophilia A.

: Severe form of haemophilia in women is an extremely rare condition. Owing to the rarity of the disease there are no precise recommendations concerning the optimal management of pregnancy and delivery in these patients. We are reporting the clinical course and management of a 30-year-old woman with a severe form of haemophilia A (factor VIII <1 IU/dl) during her first pregnancy and delivery. Antepartum, she was treated on demand by FVIII concentrate and she delivered at 37 weeks of gestation by cesarean section. In postpartal period an excellent control of bleeding was obtained by regularly administering FVIII concentrate for several days as well by concomitant use of tranexamic acid and oral contraceptive pills in the next 6 weeks.

Changes in prothrombin and activated partial thromboplastin time during replacement therapy with human recombinant growth hormone in growth hormone deficient adults.

BACKGROUND: In rodents, Growth Hormone (GH) has been shown to stimulate coagulation parameters, including Prothrombin Time (PT), activated Partial Thromboplastin Time (aPTT) and vitamin K dependent coagulation factors. However, there are no reports on the influence of GH replacement therapy on global coagulation tests in Growth Hormone Deficiency (GHD). OBJECTIVE: The aim of this study was to investigate the effects of GH administration on basic coagulation parameters: PT, aPTT and fibrinogen concentrations in adult GHD patients before and during one year of GH replacement. DESIGN: Twenty-one adult patients with severe GHD (mean age +/- SE: 38.6 +/- 2.8 years) were included in this hospital based, prospective, interventional study. All patients were treated with rhGH for 12 months (GH dose: 0.4 mg/day for male and 0.6 mg/day for female patients). IGF-1 concentrations were determined using RIA-INEP kits. Basic coagulation tests, i.e. aPTT and fibrinogen concentrations, were measured before and after 3, 6 and 12 months of treatment with rhGH. Control values were obtained from fourteen "healthy" subjects matched by age, sex and body mass index (BMI). RESULTS: At baseline, we observed no significant differences in PT, aPTT and fibrinogen values between GHD and healthy subjects. IGF-1 concentrations increased significantly within 3 months of GH therapy (8.2 +/- 1.5 vs. 24.2 +/- 2.9 nmol/l, p <0.05) and remained stable thereafter. A significant increase in PT values, which was more pronounced in female subjects, was noted after 6 and 12 months of treatment with GH. aPTT values increased significantly after 12 months of treatment only in male patients (28.8 +/- 4.6 vs. 39.7 +/- 2.1 s.; p <0.05). No significant changes in fibrinogen concentrations were found during the study. CONCLUSIONS: Twelve months of GH replacement therapy led to a significant increase in PT and aPTT values in adult GHD patients, while fibrinogen concentrations did not change. Changes in PT were more pronounced in female GHD patients, while an increase in aPTT values was observed only in male patients with GHD. The clinical significance of these changes needs further evaluation.