Genetic risk factors for venous thromboembolism

Risk Stratification and Management of Intermediate- and High-Risk Pulmonary Embolism

Acute pulmonary embolism (PE) is a leading cause of mortality. Not only is PE associated with short-term mortality, but up to ~20% of patients might suffer from long-term consequences such as post-PE syndrome and chronic thromboembolic pulmonary hypertension. Current risk stratification tools poorly predict those who are at risk for short-term deterioration and those who develop long-term consequences. Traditionally, systemic thrombolysis has been considered the first-line therapy for patients with high-risk PE without contraindications; however, it comes with the risk of major bleeding (notably intracranial hemorrhage). The use of catheter-directed interventions (embolectomy or thrombolysis) has been increasing owing to their low bleeding risk; however, randomized trial data supporting their efficacy in improving clinical outcomes are limited. In this review, we highlight the evidence supporting the available advanced therapies for high- and intermediate-risk PE and summarize the ongoing trials which are evaluating these therapies.

Thromboembolic events in people with cancer during the COVID-19 pandemic: case-control study

OBJECTIVE

to analyze the association between coronavirus disease infection and thromboembolic events in people with cancer in the first year of the pandemic.

METHOD

case-control study carried out by collecting medical records. The selected cases were adults with cancer, diagnosed with a thromboembolic event, treated in the selected service units during the first year of the pandemic. The control group included adults with cancer without a diagnosis of a thromboembolic event. Pearson's chi-square test was applied to verify the association between risk factors and the outcome and logistic regression techniques were applied to identify the odds ratio for the occurrence of a thromboembolic event.

RESULTS

there were 388 cases and 440 control cases included in the study (ratio 1/1). Females predominated, who were white, with mean age of 58.2 (±14.8) years. Antineoplastic chemotherapy was the most used treatment and coronavirus disease was identified in 11.59% of participants. In the case group, deep vein thrombosis was more prevalent.

CONCLUSION

the study confirmed the hypothesis that coronavirus disease infection did not increase the chance of thromboembolic events in people with cancer. For the population studied, the factors that were associated with these events were those related to cancer and its treatment.

HIGHLIGHTS

(1) Deep vein thrombosis was what prevailed in the studied population. (2) Chemotherapy increased the chance of thromboembolic events by 65%. (3) Thromboembolic events showed a significant association with a higher death rate as the outcome. (4) COVID-19 did not increase the risk of thromboembolic events in people with cancer.

Multimorbidity disease clusters are associated with venous thromboembolism: an extended cross-sectional national study

Multimorbidity, i.e., two or more non-communicable diseases (NCDs), is an escalating challenge for society. Venous thromboembolism (VTE) is a common cardiovascular disease and it is unknown which multimorbidity clusters associates with VTE. Our aim was to examine the association between different common disease clusters of multimorbidity and VTE. The study is an extended (1997-2015) cross-sectional Swedish study using the National Patient Register and the Multigeneration Register. A total of 2,694,442 Swedish-born individuals were included in the study. Multimorbidity was defined by 45 NCDs. A principal component analysis (PCA) identified multimorbidity disease clusters. Odds ratios (OR) for VTE were calculated for the different multimorbidity disease clusters. There were 16% (n = 440,742) of multimorbid individuals in the study population. Forty-four of the individual 45 NCDs were associated with VTE. The PCA analysis identified nine multimorbidity disease clusters, F1-F9. Seven of these multimorbidity clusters were associated with VTE. The adjusted OR for VTE in the multimorbid patients was for the first three clusters: F1 (cardiometabolic diseases) 3.44 (95%CI 3.24-3.65), F2 (mental disorders) 2.25 (95%CI 2.14-2.37) and F3 (digestive system diseases) 4.35 (95%CI 3.63-5.22). There was an association between multimorbidity severity and OR for VTE. For instance, the occurrence of at least five diseases was in F1 and F2 associated with ORs for VTE: 8.17 (95%CI 6.32-10.55) and 6.31 (95%CI 4.34-9.17), respectively. In this nationwide study we have shown a strong association between VTE and different multimorbidity disease clusters that might be useful for VTE prediction.

Initiating male contraception methods

Non-surgical (reversible) male contraception methods, when approved for general clinical application, should be made available to all interested men aged 18 50 years in good general health regardless of their semen parameters. In the preliminary workup, a complete personal and family history aimed at identifying specific conditions that may potentially increase the risks for adverse effects (associated with testosterone replacement) is advisable but a general or andrological examination is not required, unless indicated by the history. Baseline body weight, blood pressure and haemoglobin should be recorded for the purpose of future monitoring. While risks and benefits of vasectomy have been well established, appropriately nuanced patient counselling and assessment are essential for ensuring a satisfactory outcome of vasectomy.

Increased risk of venous thromboembolism in young and middle-aged individuals with hereditary angioedema: a family study

ABSTRACT

Hereditary angioedema (HAE), caused by C1 inhibitor protein deficiency, was recently shown to be associated with an increased risk for venous thromboembolism (VTE). To our knowledge, this is the first national family study of HAE, which aimed to determine the familial risk of VTE. The Swedish Multi-Generation Register was linked to the Swedish National Patient Register for the period of 1964 to 2018. Only patients with HAE with a validated diagnosis were included in the study and were linked to their family members. Hazard ratios (HRs) and 95% confidence intervals (CIs) for VTE were calculated for patients with HAE in comparison with relatives without HAE. Among 2006 individuals (from 276 pedigrees of 365 patients with HAE), 103 individuals were affected by VTE. In total, 35 (9.6%) patients with HAE were affected by VTE, whereas 68 (4.1%) non-HAE relatives were affected (P < .001). The adjusted HR for VTE among patients with HAE was 2.51 (95% CI, 1.67-3.77). Patients with HAE were younger at the first VTE than their non-HAE relatives (mean age, 51 years vs 63 years; P < .001). Before the age of 70 years, the HR for VTE among patients with HAE was 3.62 (95% CI, 2.26-5.80). The HR for VTE for patients with HAE born after 1964 was 8.29 (95% CI, 2.90-23.71). The HR for VTE for patients with HAE who were born in 1964 or earlier was 1.82 (95% CI, 1.14-2.91). HAE is associated with VTE among young and middle-aged individuals in Swedish families with HAE. The effect size of the association is in the order of other thrombophilias. We suggest that HAE may be considered a new rare thrombophilia.

Thrombophilia Screening: Not So Straightforward

Although inherited thrombophilias are lifelong risk factors for a first thrombotic episode, progression to thrombosis is multifactorial and not all individuals with inherited thrombophilia develop thrombosis in their lifetimes. Consequently, indiscriminate screening in patients with idiopathic thrombosis is not recommended, since presence of a thrombophilia does not necessarily predict recurrence or influence management, and testing should be selective. It follows that a decision to undertake laboratory detection of thrombophilia should be aligned with a concerted effort to identify any significant abnormalities, because it will inform patient management. Deficiencies of antithrombin and protein C are rare and usually determined using phenotypic assays assessing biological activities, whereas protein S deficiency (also rare) is commonly detected with antigenic assays for the free form of protein S since available activity assays are considered to lack specificity. In each case, no single phenotypic assay is capable of detecting every deficiency, because the various mutations express different molecular characteristics, rendering thrombophilia screening repertoires employing one assay per potential deficiency, of limited effectiveness. Activated protein C resistance (APCR) is more common than discrete deficiencies of antithrombin, protein C, and protein S and also often detected initially with phenotypic assays; however, some centres perform only genetic analysis for factor V Leiden, as this is responsible for most cases of hereditary APCR, accepting that acquired APCR and rare F5 mutations conferring APCR will go undetected if only factor V Leiden is evaluated. All phenotypic assays have interferences and limitations, which must be factored into decisions about if, and when, to test, and be given consideration in the laboratory during assay performance and interpretation. This review looks in detail at performance and limitations of routine phenotypic thrombophilia assays.

Under the dual effect of inflammation and pulmonary fibrosis, CTD-ILD patients possess a greater susceptibility to VTE

As an autoimmune disease, the persistent systemic inflammatory response associated with connective tissue disease (CTD) is involved in the development of venous thromboembolism (VTE). However, clinical data showed that the risk of VTE in patients differed between subtypes of CTD, suggesting that different subtypes may have independent mechanisms to promote the development of VTE, but the specific mechanism lacks sufficient research at present. The development of pulmonary fibrosis also contributes to the development of VTE, and therefore, patients with CTD-associated interstitial lung disease (CTD-ILD) may be at higher risk of VTE than patients with CTD alone or patients with ILD alone. In addition, the activation of the coagulation cascade response will drive further progression of the patient's pre-existing pulmonary fibrosis, which will continue to increase the patient's risk of VTE and adversely affect prognosis. Currently, the treatment for CTD-ILD is mainly immunosuppressive and antirheumatic therapy, such as the use of glucocorticoids and janus kinase-inhibitors (JAKis), but, paradoxically, these drugs are also involved in the formation of patients' coagulation tendency, making the clinical treatment of CTD-ILD patients with a higher risk of developing VTE challenging. In this article, we review the potential risk factors and related mechanisms for the development of VTE in CTD-ILD patients to provide a reference for clinical treatment and prevention.

The genetic causal relationship between type 2 diabetes, glycemic traits and venous thromboembolism, deep vein thrombosis, pulmonary embolism: a two-sample Mendelian randomization study

OBJECTIVE

To investigate the genetic underpinnings of the association between type 2 diabetes (T2D), glycemic indicators such as fasting glucose (FG), fasting insulin (FI), and glycated hemoglobin (GH), and venous thromboembolism (VTE), encompassing deep vein thrombosis (DVT) and pulmonary embolism (PE), thereby contributing novel insights to the scholarly discourse within this domain.

METHODS

Genome-wide association study (GWAS) summary data pertaining to exposures (T2D, FG, FI, GH) and outcomes (VTE, DVT, PE) were acquired from the IEU Open GWAS database, encompassing participants of European descent, including both male and female individuals. Two-sample Mendelian randomization (MR) analyses were conducted utilizing the TwoSampleMR and MRPRESSO packages within the R programming environment. The primary analytical approach employed was the random-effects inverse variance weighted (IVW) method. Heterogeneity was assessed via Cochran's Q statistic for MR-IVW and Rucker's Q statistic for MR-Egger. Horizontal pleiotropy was evaluated using the intercept test of MR Egger and MR pleiotropy residual sum and outlier (MR-PRESSO) analysis, with the latter also employed for outlier detection. Additionally, a "Leave one out" analysis was conducted to ascertain the influence of individual single nucleotide polymorphisms (SNPs) on MR results.

RESULTS

The random-effects IVW analysis revealed a negative genetic causal association between T2D) and VTE (P = 0.008, Odds Ratio [OR] 95% confidence interval [CI] = 0.896 [0.827-0.972]), as well as between FG and VTE (P = 0.002, OR 95% CI = 0.655 [0.503-0.853]), GH and VTE (P = 0.010, OR 95% CI = 0.604 [0.412-0.884]), and GH and DVT (P = 0.002, OR 95% CI = 0.413 [0.235-0.725]). Conversely, the random-effects IVW analysis did not detect a genetic causal relationship between FI and VTE (P > 0.05), nor between T2D, FG, or FI and DVT (P > 0.05), or between T2D, FG, FI, or GH and PE (P > 0.05). Both the Cochran's Q statistic for MR-IVW and Rucker's Q statistic for MR-Egger indicated no significant heterogeneity (P > 0.05). Moreover, the intercept tests of MR Egger and MR-PRESSO suggested the absence of horizontal pleiotropy (P > 0.05). MR-PRESSO analysis identified no outliers, while the "Leave one out" analysis underscored that the MR analysis was not influenced by any single SNP.

CONCLUSION

Our investigation revealed that T2D, FG, and GH exhibit negative genetic causal relationships with VTE at the genetic level, while GH demonstrates a negative genetic causal relationship with DVT at the genetic level. These findings furnish genetic-level evidence warranting further examination of VTE, DVT, and PE, thereby making a contribution to the advancement of related research domains.

The risk for venous thromboembolism and cardiometabolic disorders in offspring from thrombosis-prone pedigrees

BACKGROUND

Most family studies on venous thromboembolism (VTE) have focused on first-degree relatives.

OBJECTIVES

We took a pedigree-based approach and examined the risk of VTE and cardiometabolic disorders in offspring from extended pedigrees according to the densities of VTE in pedigrees.

METHODS

From the Swedish population, we identified a total of 482 185 pedigrees containing a mean of 14.2 parents, aunts/uncles, grandparents, and cousins of a core full sibship that we termed the pedigree offspring (n = 751 060). We then derived 8 empirical classes of these pedigrees based on the density of cases of VTE. The risk was determined in offspring for VTE and cardiometabolic disorders as a function of VTE density in their pedigrees. Bonferroni correction for multiple comparisons was performed.

RESULTS

VTE was unevenly distributed in the population; the Gini coefficient was 0.59. Higher VTE density in pedigrees was associated in the offspring with a higher risk of different VTE manifestations (deep venous thrombosis, pulmonary embolism, pregnancy-related VTE, unusual thrombosis, and superficial thrombophlebitis), thrombophilia, and lower age of first VTE event. Moreover, VTE density in pedigrees was significantly associated in the offspring with obesity, diabetes, gout, varicose veins, and arterial embolism and thrombosis (excluding brain and heart). No significant associations were observed for retinal vein occlusion, hypercholesterolemia, hypertension, coronary heart disease, myocardial infarction, ischemic stroke, atrial fibrillation, heart failure, primary pulmonary hypertension, cerebral hemorrhage, aortic aneurysm, peripheral artery disease, and overall mortality.

CONCLUSION

Offspring of pedigrees with a high density of VTE are disadvantaged regarding VTE manifestations and certain cardiometabolic disorders.

Research into New Molecular Mechanisms in Thrombotic Diseases Paves the Way for Innovative Therapeutic Approaches

Thrombosis is a multifaceted process involving various molecular components, including the coagulation cascade, platelet activation, platelet-endothelial interaction, anticoagulant signaling pathways, inflammatory mediators, genetic factors and the involvement of various cells such as endothelial cells, platelets and leukocytes. A comprehensive understanding of the molecular signaling pathways and cell interactions that play a role in thrombosis is essential for the development of precise therapeutic strategies for the treatment and prevention of thrombotic diseases. Ongoing research in this field is constantly uncovering new molecular players and pathways that offer opportunities for more precise interventions in the clinical setting. These molecular insights into thrombosis form the basis for the development of targeted therapeutic approaches for the treatment and prevention of thrombotic disease. The aim of this review is to provide an overview of the pathogenesis of thrombosis and to explore new therapeutic options.

Analysis of PROC mutations and clinical features in 22 unrelated families with inherited protein C deficiency

Currently, limited information is available in the literature regarding the relationships between PROC mutations and clinical features in Chinese individuals. We aimed to characterize severe congenital Protein C deficiency in 22 unrelated Chinese families in a tertiary hospital by analyzing its clinical manifestation, associated risk factors, and gene mutations. We measured protein C activity and antigen levels for all participants, screened them for mutations in the PROC gene, and analyzed the clinical features of each family to identify commonalities and differences. The analysis revealed a total of 75 individuals with PCD and 16 different PROC mutations, including 12 missense mutations and 4 deletion mutations. Among them, 11 who were compound heterozygotes or homozygotes for mutations tended to develop symptoms at a younger age without any clear triggers. In contrast, the remaining 64 individuals who were heterozygotes for mutations often had clear triggers for their symptoms and experienced a milder course of the disease. It is worth noting that the mutation c.565C > T occurred most frequently, being identified in 8 out of 22 families (36%). Our team also reported five novel mutations, including c.742-744delAAG, c.383G > A, c.997G > A, c.1318C > T, and c.833T > C mutations. The identification of five novel mutations adds to the richness of the Human Genome Database. Asymptomatic heterozygotes are not uncommon, and they are prone to develop symptoms with obvious triggers. The evidence presented strongly suggest that asymptomatic individuals with family history of protein C deficiency can benefit from mutational analysis of PROC gene.

Factors Associated with Hospital Length of Stay among VTE Cases: Insights from the i-RegVed Registry

INTRODUCTION

Venous thromboembolism (VTE) is a multifactorial condition and one of the leading causes of mortality and disability. The present study explores the factors associated with hospitalization duration among different types of venous thromboembolism diagnoses, such as deep vein thrombosis (DVT), pulmonary embolism (PE), and other forms of thrombosis.

METHODS

The data included participants with VTE admitted to 13 hospitals within pan-India from June 2022 to December 2023 to the i-RegVed registry, where socio-demographic data, clinical history, and various factors associated with hospital length of stay (LOS) were included for analyses. Multilinear regression was performed to explore the factors associated with hospital LOS among VTE conditions such as DVT, PE, forms of thrombosis other than PE and DVT, and all VTE diagnoses.

RESULTS

A total of 633 participants were included in the study, with 55% being males, and 28.9% being homemakers. Longer hospital LOS was significantly associated with age (β = -.09, P < .05), sex (β = 3.21, P < .05), and non-communicable diseases (β = 3.51, P < .05) among participants with DVT and among participants with at least one of the VTE diagnoses, age (β = -.12, P < .001) and anticoagulant use (β = -2.49, P < .05) was significantly associated.

CONCLUSION

The findings provide insights into the factors influencing hospital outcomes among participants with different types of VTE, highlighting the importance of age and comorbidities in predicting the hospital LOS.

Recent Advances on the Molecular Mechanism and Clinical Trials of Venous Thromboembolism

Venous thromboembolism is a condition that includes deep vein thrombosis and pulmonary embolism. It is the third most common cardiovascular disease behind acute coronary heart disease and stroke. Over the past few years, growing research suggests that venous thrombosis is also related to the immune system and inflammatory factors have been confirmed to be involved in venous thrombosis. The role of inflammation and inflammation-related biomarkers in cerebrovascular thrombotic disease is the subject of ongoing debate. P-selectin leads to platelet-monocyte aggregation and stimulates vascular inflammation and thrombosis. The dysregulation of miRNAs has also been reported in venous thrombosis, suggesting the involvement of miRNAs in the progression of venous thrombosis. Plasminogen activator inhibitor-1 (PAI-1) is a crucial component of the plasminogen-plasmin system, and elevated levels of PAI-1 in conjunction with advanced age are significant risk factors for thrombosis. In addition, it has been showed that one of the ways that neutrophils promote venous thrombosis is the formation of neutrophil extracellular traps (NETs). In recent years, the role of extracellular vesicles (EVs) in the occurrence and development of VTE has been continuously revealed. With the advancement of research technology, the complex regulatory role of EVs on the coagulation process has been gradually discovered. However, our understanding of the causes and consequences of these changes in venous thrombosis is still limited. Therefore, we review our current understanding the molecular mechanisms of venous thrombosis and the related clinical trials, which is crucial for the future treatment of venous thrombosis.

Venous Thromboembolism in Women of Childbearing Age: Insights from the START Registry

BACKGROUND

 Women of childbearing age are exposed to venous thromboembolic risk mainly for pregnancy and use of oral contraceptives. The impact of risk factors (RF) on venous thromboembolism (VTE) in these circumstances is still unclear.

AIM

 In the context of START registry, we aimed to investigate the weight of a series of RF on the occurrence of pregnancy- or combined oral contraceptive (COC)-associated VTE.

MATERIALS AND METHODS

 We selected all women included in the START for VTE occurred between 18-42 years and compared those with a first or recurrent pregnancy/postpartum- (group A) or COC-VTE (group B) with those who had VTE outside these circumstances (group C). Final analysis included a cohort of 532 women. Follow-up data showed that there were no significant differences between the groups in terms of thrombotic and haemorrhagic complications. As for pregnancy-associated VTE, the overall outcome was good in terms of both maternal and fetal prognosis.

RESULTS

 In a binary model of logistic regression, correcting for potential confounders, VTE family history conferred a significant and independent higher risk of COC-VTE compared with group C. Similarly, comparison between group A and C documented that family history significantly affected the risk of pregnancy-associated VTE. VTE in the group C was significantly associated with older age. Lastly, smoke was a significant risk factor for pregnancy/postpartum VTE when group A and group B were compared.

CONCLUSION

 Present data suggest that in the setting of fertile women, family history of VTE has a greater role in predicting COC- and pregnancy/postpartum- VTE than outside these circumstances.

Evaluation of prothrombotic risk of two PROC hotspot mutations (Arg189Trp and Lys193del) in Chinese population: a retrospective study

BACKGROUND

R189W and K193del of protein C (PC) were hotspot mutations in Chinese population with venous thromboembolism (VTE), but almost two-thirds of patients with above mutations coexisting with other genetically or aquiredly prothrombotic risk factors. The aim of this study is to clarify the independent contributions of R189W or K193del to VTE risk.

METHODS

490 unrelated patients with a personal history of VTE and 410 healthy participants were enrolled in this study. Data of their demographics, family history, genetic and acquired thrombosis risk factors were collected and statistically analyzed.

RESULTS

PC R189W and K193del were identified in 3/410 (0.7%) and 7/410 (1.7%) healthy controls, and in 27/490 (5.5%) and 43/490 (8.8%) patients with VTE, respectively. Notably, about 70% of these mutant carriers combined with other genetic or acquired thrombophilic factors. After adjustment for age, gender, other inherited and acquired risk factors, we demonstrated that R189W and K193del were associated with 5.781-fold and 4.365-fold increased risk of VTE, respectively, which were significantly lower than the prothrombotic risk of anticoagulant deficiencies induced from rare mutations. Independent R189W or K193del mutation was not associated with earlier first-onset age as well as higher recurrent rate of VTE. However, combination of other genetic or acquired thrombophilic factors had supra-additive effects on those consequences. The more additional risk factors the patients had, the younger first-onset ages and higher risk of recurrence would be.

CONCLUSIONS

As the most frequent mutations for PC deficiency in Chinese population, both R189W and K193del mutations had limited independent contributions to VTE development compared with other rare mutations in PROC gene, but may act in concert with other genetic defects or acquired thrombotic risk factors to produce the final severe phenotype.

Dynamic observation of circRNA and mRNA profiles in a rat model of deep vein thrombosis

The goal of the present study was to identify different transcriptome expression profiles involved in the pathogenesis of deep vein thrombosis (DVT), and to illustrate the diagnostic and therapeutic potential of circular RNAs (circRNAs) and mRNAs in DVT progression. A Sprague-Dawley rat model of DVT was successfully established through the stenosis method and samples were sequenced at four time points (1, 6 and 12 h, and 3 days after ligation) to observe the dynamic changes in circRNAs and mRNAs during DVT progression. RNA sequencing was used to analyze the circRNA and mRNA expression profiles, and associated functions and pathways, in the blood of DVT rats at the four time points. In addition, Short Time Series Expression Miner (STEM) analysis was performed to explore temporal gene expression. Differential expression of 1,680, 4,018, 3,724, and 3,036 circRNAs, and 400, 1,176, 373, and 573 mRNAs was observed in the 1, 6 and 12 h, and 3-day groups, respectively, compared with the sham group (fold change >2.0 or <-2.0, P<0.05). Functional enrichment analysis indicated that differentially expressed mRNAs were associated with the following terms: Immune response, cell activation, blood stasis facilitated organelle, extracellular membrane-bounded organelle, and blood microparticle, oxygen transporter activity. STEM analysis indicated that the expression of 366 circRNAs in circRNA profile 45 and 270 mRNAs in mRNA profile 45 was consistent with thrombus progression. Enrichment analysis was performed on mRNA profile 45. The main Gene Ontology annotations were chromosome segregation, mitotic sister chromatid segregation, cell cycle process, and ligand-dependent nuclear receptor transcription coactivator activity. Pathway enrichment analysis identified the platelet-associated pathway, immune-associated pathway, and inflammation-relation pathway. According to the enriched platelet-associated pathways, four mRNAs and ten candidate circRNAs were selected for reverse transcription-quantitative PCR verification. The expression of nine of the ten circRNAs and all four mRNAs was consistent with the sequencing results. In summary, differentially expressed circRNAs and mRNAs are dynamically involved in DVT development. Dysregulated transcriptome profiles and the corresponding functions and pathways may provide mechanistic insights into DVT diagnosis and treatment.

Practice and development of male contraception: European Academy of Andrology and American Society of Andrology guidelines

BACKGROUNDS

Despite a wide spectrum of contraceptive methods for women, the unintended pregnancy rate remains high (45% in the US), with 50% resulting in abortion. Currently, 20% of global contraceptive use is male-directed, with a wide variation among countries due to limited availability and lack of efficacy. Worldwide studies indicate that >50% of men would opt to use a reversible method, and 90% of women would rely on their partner to use a contraceptive. Additional reasons for novel male contraceptive methods to be available include the increased life expectancy, sharing the reproductive risks among partners, social issues, the lack of pharma industry involvement and the lack of opinion makers advocating for male contraception.

AIM

The present guidelines aim to review the status regarding male contraception, the current state of the art to support the clinical practice, recommend minimal requirements for new male contraceptive development and provide and grade updated, evidence-based recommendations from the European Society of Andrology (EAA) and the American Society of Andrology (ASA).

METHODS

An expert panel of academicians appointed by the EAA and the ASA generated a consensus guideline according to the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) system.

RESULTS

Sixty evidence-based and graded recommendations were produced on couple-centered communication, behaviors, barrier methods, semen analysis and contraceptive efficacy, physical agents, surgical methods, actions before initiating male contraception, hormonal methods, non-hormonal methods, vaccines, and social and ethical considerations.

CONCLUSION

As gender roles transform and gender equity is established in relationships, the male contribution to family planning must be facilitated. Efficient and safe male-directed methods must be evaluated and introduced into clinical practice, preferably reversible, either hormonal or non-hormonal. From a future perspective, identifying new hormonal combinations, suitable testicular targets, and emerging vas occlusion methods will produce novel molecules and products for male contraception.

A combination of strongly associated prothrombotic single nucleotide polymorphisms could efficiently predict venous thrombosis risk

Background

Venous thrombosis (VT) is multifactorial trait that contributes to the global burden of cardiovascular diseases. Although abundant single nucleotide polymorphisms (SNPs) provoke the susceptibility of an individual to VT, research has found that the five most strongly associated SNPs, namely, rs6025 (F5 Leiden), rs2066865 (FGG), rs2036914 (F11), rs8176719 (ABO), and rs1799963 (F2), play the greatest role. Association and risk prediction models are rarely established by using merely the five strongly associated SNPs. This study aims to explore the combined VT risk predictability of the five SNPs and well-known non-genetic VT risk factors such as aging and obesity in the Hungarian population.

Methods

SNPs were genotyped in the VT group (n = 298) and control group (n = 400). Associations were established using standard genetic models. Genetic risk scores (GRS) [unweighted GRS (unGRS), weighted GRS (wGRS)] were also computed. Correspondingly, the areas under the receiver operating characteristic curves (AUCs) for genetic and non-genetic risk factors were estimated to explore their VT risk predictability in the study population.

Results

rs6025 was the most prevalent VT risk allele in the Hungarian population. Its risk allele frequency was 3.52-fold higher in the VT group than that in the control group [adjusted odds ratio (AOR) = 3.52, 95% CI: 2.50-4.95]. Using all genetic models, we found that rs6025 and rs2036914 remained significantly associated with VT risk after multiple correction testing was performed. However, rs8176719 remained statistically significant only in the multiplicative (AOR = 1.33, 95% CI: 1.07-1.64) and genotypic models (AOR = 1.77, 95% CI: 1.14-2.73). In addition, rs2066865 lost its significant association with VT risk after multiple correction testing was performed. Conversely, the prothrombin mutation (rs1799963) did not show any significant association. The AUC of Leiden mutation (rs6025) showed better discriminative accuracy than that of other SNPs (AUC = 0.62, 95% CI: 0.57-0.66). The wGRS was a better predictor for VT than the unGRS (AUC = 0.67 vs. 0.65). Furthermore, combining genetic and non-genetic VT risk factors significantly increased the AUC to 0.89 with statistically significant differences (Z = 3.924, p < 0.0001).

Conclusions

Our study revealed that the five strongly associated SNPs combined with non-genetic factors could efficiently predict individual VT risk susceptibility. The combined model was the best predictor of VT risk, so stratifying high-risk individuals based on their genetic profiling and well-known non-modifiable VT risk factors was important for the effective and efficient utilization of VT risk preventive and control measures. Furthermore, we urged further study that compares the VT risk predictability in the Hungarian population using the formerly discovered VT SNPs with the novel strongly associated VT SNPs.

Identification of potential genetic Loci and polygenic risk model for Budd-Chiari syndrome in Chinese population

Budd-Chiari syndrome (BCS) is characterized by hepatic venous outflow obstruction, posing life-threatening risks in severe cases. Reported risk factors include inherited and acquired hypercoagulable states or other predisposing factors. However, many patients have no identifiable etiology, and causes of BCS differ between the West and East. This study recruited 500 BCS patients and 696 normal individuals for whole-exome sequencing and developed a polygenic risk scoring (PRS) model using PLINK, LASSOSUM, BLUP, and BayesA methods. Risk factors for venous thromboembolism and vascular malformations were also assessed for BCS risk prediction. Ultimately, we discovered potential BCS risk mutations, such as rs1042331, and the optimal BayesA-generated PRS model presented an AUC >0.9 in the external replication cohort. This model provides particular insights into genetic risk differences between China and the West and suggests shared genetic risks among BCS, venous thromboembolism, and vascular malformations, offering different perspectives on BCS pathogenesis.

A hypothesis - generating Swedish extended national cross-sectional family study of multimorbidity severity and venous thromboembolism

OBJECTIVES

Venous thromboembolism (VTE) is a common worldwide disease. The burden of multimorbidity, that is, two or more chronic diseases, has increased. Whether multimorbidity is associated with VTE risk remains to be studied. Our aim was to determine any association between multimorbidity and VTE and any possible shared familial susceptibility.

DESIGN

A nationwide extended cross-sectional hypothesis - generating family study between 1997 and 2015.

SETTING

The Swedish Multigeneration Register, the National Patient Register, the Total Population Register and the Swedish cause of death register were linked.

PARTICIPANTS

2 694 442 unique individuals were analysed for VTE and multimorbidity.

MAIN OUTCOMES AND MEASURES

Multimorbidity was determined by a counting method using 45 non-communicable diseases. Multimorbidity was defined by the occurrence of ≥2 diseases. A multimorbidity score was constructed defined by 0, 1, 2, 3, 4 or 5 or more diseases.

RESULTS

Sixteen percent (n=440 742) of the study population was multimorbid. Of the multimorbid patients, 58% were females. There was an association between multimorbidity and VTE. The adjusted odds ratio (OR) for VTE in individuals with multimorbidity (2 ≥ diagnoses) was 3.16 (95% CI: 3.06 to 3.27) compared with individuals without multimorbidity. There was an association between number of diseases and VTE. The adjusted OR was 1.94 (95% CI: 1.86 to 2.02) for one disease, 2.93 (95% CI: 2.80 to 3.08) for two diseases, 4.07 (95% CI: 3.85 to 4.31) for three diseases, 5.46 (95% CI: 5.10 to 5.85) for four diseases and 9.08 (95% CI: 8.56 to 9.64) for 5 ≥ diseases. The association between multimorbidity and VTE was stronger in males OR 3.45 (3.29 to 3.62) than in females OR 2.91 (2.77 to 3.04). There were significant but mostly weak familial associations between multimorbidity in relatives and VTE.

CONCLUSIONS

Increasing multimorbidity exhibits a strong and increasing association with VTE. Familial associations suggest a weak shared familial susceptibility. The association between multimorbidity and VTE suggests that future cohort studies where multimorbidity is used to predict VTE might be worthwhile.

Long-term ambient air pollution and venous thromboembolism in a population-based Swedish cohort

Air pollution is a major contributor to the global burden of disease and has been linked to several diseases and conditions, including cardiovascular disease. The biological mechanisms are related to inflammation and increased coagulability, factors that play an important role in the pathogenesis of venous thromboembolism (VTE, i.e., deep vein thrombosis or pulmonary embolism). This study investigates if long-term exposure to air pollution is associated with increased VTE incidence. The study followed 29 408 participants from the Malmö Diet and Cancer (MDC) cohort, which consists of adults aged 44-74 recruited in Malmö, Sweden between 1991 and 1996. For each participant, annual mean residential exposures to particulate matter <2.5 μg (PM_2.5) and <10 μg (PM₁₀), nitrogen oxides (NO_x) and black carbon (BC) from 1990 up to 2016 were calculated. Associations with VTE were analysed using Cox proportional hazard models for air pollution in the year of the VTE event (lag0) and the mean of the prior 1-10 years (lag1-10). Annual air pollution exposures for the full follow-up period had the following means: 10.8 μg/m³ for PM_2.5, 15.8 μg/m³ for PM₁₀, 27.7 μg/m³ for NO_x, and 0.96 μg/m³ for BC. The mean follow-up period was 19.5 years, with 1418 incident VTE events recorded during this period. Exposure to lag1-10 PM_2.5 was associated with an increased risk of VTE (HR 1.17 (95%CI 1.01-1.37)) per interquartile range (IQR) of 1.2 μg/m³ increase in PM_2.5 exposure. No significant associations were found between other pollutants or lag0 PM_2.5 and incident VTE. When VTE was divided into specific diagnoses, associations with lag1-10 PM_2.5 exposure were similarly positive for deep vein thrombosis but not for pulmonary embolism. Results persisted in sensitivity analyses and in multi-pollutant models. Long-term exposure to moderate concentrations of ambient PM_2.5 was associated with increased risks of VTE in the general population in Sweden.

Genome-wide association analyses identified novel susceptibility loci for pulmonary embolism among Han Chinese population

BACKGROUND

A large proportion of pulmonary embolism (PE) heritability remains unexplained, particularly among the East Asian (EAS) population. Our study aims to expand the genetic architecture of PE and reveal more genetic determinants in Han Chinese.

METHODS

We conducted the first genome-wide association study (GWAS) of PE in Han Chinese, then performed the GWAS meta-analysis based on the discovery and replication stages. To validate the effect of the risk allele, qPCR and Western blotting experiments were used to investigate possible changes in gene expression. Mendelian randomization (MR) analysis was employed to implicate pathogenic mechanisms, and a polygenic risk score (PRS) for PE risk prediction was generated.

RESULTS

After meta-analysis of the discovery dataset (622 cases, 8853 controls) and replication dataset (646 cases, 8810 controls), GWAS identified 3 independent loci associated with PE, including the reported loci FGG rs2066865 (p-value = 3.81 × 10^-14), ABO rs582094 (p-value = 1.16 × 10^-10) and newly reported locus FABP2 rs1799883 (p-value = 7.59 × 10^-17). Previously reported 10 variants were successfully replicated in our cohort. Functional experiments confirmed that FABP2-A163G(rs1799883) promoted the transcription and protein expression of FABP2. Meanwhile, MR analysis revealed that high LDL-C and TC levels were associated with an increased risk of PE. Individuals with the top 10% of PRS had over a fivefold increased risk for PE compared to the general population.

CONCLUSIONS

We identified FABP2, related to the transport of long-chain fatty acids, contributing to the risk of PE and provided more evidence for the essential role of metabolic pathways in PE development.

Epidemiology and prevention of venous thromboembolism

Venous thromboembolism, that consists of the interrelated conditions deep-vein thrombosis and pulmonary embolism, is an under-appreciated vascular disease. In Western regions, approximately 1 in 12 individuals will be diagnosed with venous thromboembolism in their lifetime. Rates of venous thromboembolism are lower in Asia, but data from other regions are sparse. Numerous risk factors for venous thromboembolism have been identified, which can be classified as acute or subacute triggers (provoking factors that increase the risk of venous thromboembolism) and basal or acquired risk factors (which can be modifiable or static). Approximately 20% of individuals who have a venous thromboembolism event die within 1 year (although often from the provoking condition), and complications are common among survivors. Fortunately, opportunities exist for primordial prevention (prevention of the development of underlying risk factors), primary prevention (management of risk factors among individuals at high risk of the condition) and secondary prevention (prevention of recurrent events) of venous thromboembolism. In this Review, we describe the epidemiology of venous thromboembolism, including the incidence, risk factors, outcomes and opportunities for prevention. Meaningful health disparities exist in both the incidence and outcomes of venous thromboembolism. We also discuss these disparities as well as opportunities to reduce them.

Venous thromboembolism: Why is it still a significant health problem?

BACKGROUND

Venous thromboembolism (VTE) remains the third leading cause of acute cardiovascular syndrome following myocardial infarction and ischemic stroke. The global burden of disease worldwide is high and shows a steady upward trend in recent years with an incidence of 1-2 per 1000 adults per year. The overarching goal of the initial management of VTE is to prevent early and late adverse outcomes. Rapid evaluation and therapeutic intervention is vital to improving prognosis.

METHODS

We searched PubMed, Science Direct and Scopus databases for articles published in the last 10 years. Additionally, some earlier articles were analyzed.

RESULTS

For the purposes of this review, we discussed how understanding the epidemiology of VTE and the current knowledge of early and late complications of this disease have shaped the current approach to VTE prevention. We also analyzed the current knowledge and the most up-to-date information about VTE in COVID-19 infection. Contemporary perspective presented in this article on mortality in VTE, the incidence of recurrences, the risk of major bleeding during therapy and the chronic complications indicate why this is a major challenge for today's medicine and a current target for further research.

CONCLUSIONS

Understanding the interaction between environmental and genetic factors appears to be crucial in the diagnostic process. It can provide insight into the pathophysiology of VTE, potentially identifying options for targeted prevention and treatment. However, due to differences in clinical presentation, diagnosing pulmonary embolism may not be an easy task which perfectly illustrates the scale and complexity of the disease.

Testing for Factor V Leiden (FVL) and Prothrombin G20210A Genetic Variants

Laboratory testing for Factor V Leiden and Prothrombin G20210A genetic variants permits defining the increased relative risk for venous thromboembolism in selected patients. Laboratory DNA testing for these variants may be undertaken by a variety of methods, including fluorescence-based quantitative real-time PCR (qPCR). This is a rapid, simple, robust, and reliable method to identify genotypes of interest. This chapter describes the method that employs PCR amplification of the patient DNA region of interest and genotyping by allele-specific discrimination technology on a quantitative real-time PCR (qPCR) instrument.

Association of Combined Lifestyle and Polygenetic Risk with Incidence of Venous Thromboembolism: A Large Population-Based Cohort Study

As one of the fatal complications, venous thromboembolism (VTE) is associated with increased mortality. However, the combined effects of adopting multiple healthy lifestyles have not been firmly demonstrated. This study was to evaluate the association of combined healthy lifestyles and genetic risk factors with VTE and to investigate their interaction. A prospective cohort study from UK Biobank with a total of 442,963 men and women aged between 38 to 73 years were recruited from 2006 to 2010 and followed up through 2017 or 2018. A polygenic risk score was constructed and a weighted healthy lifestyle score, including no current smoking, regular physical exercises, healthy diet, and healthy body mass index, was categorized. During a median follow-up 9.0 years (3,912,396 person-years), there were 6,736 (172 per 100,000 person-years) incident VTE cases recorded. Among the participants with an unfavorable lifestyle, 1.80% developed VTE, versus 1.03% of the participants with a favorable lifestyle (hazard ratio [HR]: 1.58; 95% confidence interval [CI]: 1.48-1.68). Of the participants with high genetic risk, 2.42% developed VTE, versus 0.97% of the participants with low genetic risk (HR: 2.60; 95% CI: 2.39-2.81). Moreover, of the participants with high genetic risk and unfavorable lifestyle, 2.90% developed VTE, versus 0.66% of the participants with low genetic risk and favorable lifestyle (HR: 4.09; 95% CI: 3.48-4.79). No significant interaction between genetic risk and lifestyle factors was observed (p for interaction = 0.727). An unfavorable lifestyle was associated with a substantially higher risk of VTE, regardless of the genetic risk strata.

Dabigatran in Cerebral Sinus Vein Thrombosis and Thrombophilia

Background and Purpose: Thrombophilic gene alterations are a major risk factor for cerebral sinus vein thrombosis (CSVT). Up to 30% of all patients with cerebral sinus vein thrombosis (CSVT) are found to have thrombophilic defects such as prothrombin mutation (PTM) or factor V Leiden (FVL). Their repercussions on the plasma levels of dabigatran etexilate are unclear. In this prospective case–control study, we aimed to investigate whether thrombophilia in CSVT has an influence on dabigatran peak-plasma levels. Methods: We monitored 10 patients over 12 months with acute CSVT, genetic thrombophilia with off-label use of dabigatran etexilate 150 mg twice a day and measured dabigatran peak-plasma levels and radiological outcome. We also monitored patients without genetic thrombophilia with dabigatran etexilate 150 mg twice a day and compared the efficiency and dabigatran peak-plasma levels. Results: Patients with homozygote PTM had significantly lower dabigatran peak concentration compared to patients with FVL or the control group (23 ± 4.2 vs. 152.3 ± 27.5 and 159.6 ± 63.08; p-value ≤ 0.05) There was no significant difference in dabigatran etexilate plasma levels between the heterozygote PTM group compared to patients with FVL or the control group (p = 0.29). There was no correlation between dabigatran peak concentration and delayed thrombus dissolution. Conclusions: Dabigatran peak concentration was stable in patients with heterozygote FVL and heterozygote PTM, but not in homozygote PTM, compared to controls. Genetic screening for thrombophilia in patients after CSVT may be useful to make patient tailored therapeutic decisions regarding oral anticoagulation and may decrease thrombotic events.

Acute Eosinophilic Pneumonia Complicated with Venous Thromboembolic Disease—Diagnostic and Therapeutic Considerations

Acute Eosinophilic Pneumonia (AEP) is a rare idiopathic disease caused by an accumulation of eosinophils in the pulmonary alveoli and interstitial tissue of the lungs. The onset of symptoms is acute; some patients develop respiratory failure. The diagnosis is based on clinical symptoms, diffuse interstitial infiltrates in the lungs on imaging studies, and eosinophilia exceeding 25% on bronchoalveolar lavage or pleural fluid smear. Smokers are primarily at increased risk for the disease. We present a case of venous thromboembolic disease (VTE) that developed in the course of AEP in a previously healthy male smoker. Complete remission of the disease was achieved with anticoagulation therapy combined with a low dose of steroids. Surprisingly, further diagnostics revealed the presence of thrombophilia: antithrombin (AT) deficiency and increased homocysteine level. According to our knowledge, this is the first case of VTE diagnosed in the course of AEP combined with thrombophilia.

Sex-specific aspects of venous thromboembolism: What is new and what is next?

Men seem to have a higher intrinsic risk of venous thromboembolism (VTE) than women, regardless of age. To date, this difference has not been explained. By integrating state-of-the-art research presented at the International Society on Thrombosis and Haemostasis Congress of 2021 with the available literature, we address potential explanations for this intriguing risk difference between men and women. We discuss the role of exogenous and endogenous sex hormones as the most important known sex-specific determinants of VTE risk. In addition, we highlight clues on the role of sex hormones and VTE risk from clinical scenarios such as pregnancy and the polycystic ovary syndrome. Furthermore, we address new potential sex-specific risk factors and unanswered research questions, which could provide more insight in the intrinsic risk difference between men and women, such as body height and differences in body fat distribution, leading to dysregulation of metabolism and inflammation.

Current Knowledge on Factor V Leiden Mutation as a Risk Factor for Recurrent Venous Thromboembolism: A Systematic Review and Meta-Analysis

Background

Thrombophilia screening is widely done in clinical practice, and it is claimed that the extent of venous thromboembolism (VTE) recurrence risk in patients with common defects is still not fully understood.

Aim

We aimed to summarize data of all observational studies prospectively assessing the association of heterozygous factor V Leiden (FVL) mutation and recurrent VTE in patients with VTE, and to calculate pooled relative risks (RR), overall and in various subgroups.

Methods

We searched MEDLINE and EMBASE databases for cohort studies prospectively assessing VTE recurrence in patients with and without FVL mutation (PROSPERO: CRD42021182800). Data were extracted on cohort and study-level. The methodological quality was assessed using the Newcastle-Ottawa Scale (NOS). RR were calculated overall and in subgroups using a random-effects model.

Results

From 31 cohorts, 24 studies were finally included summarizing 13,571 patients. Heterozygous FVL mutation was identified in 2,840 individuals (21%). The methodological quality was estimated to be high in 20 studies (83%). The overall RR was 1.46 (95% CI: 1.31, 1.64), consistent across subgroups.

Conclusions

Pooling all high-quality epidemiological data, the risk of recurrent VTE was increased by 46% in patients with heterozygous FVL mutation. Against the background of established risk factors, the FVL mutation plays only a marginal role in the risk assessment for recurrent VTE.

Thrombomodulin (THBD) gene variants and thrombotic risk in a population-based cohort study

BACKGROUND

The protein C anticoagulant system plays a key role in maintaining the hemostatic balance. Although several studies have identified thrombomodulin gene (THBD) variants among venous thromboembolism (VTE) patients, the role of THBD in relation to VTE in humans remains to be clarified.

OBJECTIVES

This study aimed to determine the thrombotic risk of rare and common THBD variants in a large population-based cohort of middle-aged and older adults.

PATIENTS/METHODS

The exome sequence of THBD was analyzed for qualifying variants in 28,794 subjects (born 1923-1950, 60% women), who participated in the Malmö Diet and Cancer study (1991-1996). Patients were followed from baseline until the first event of VTE, death, or 2018. Qualifying variants were defined as loss-of-function or non-benign (PolyPhen-2) missense variants with minor allele frequency <0.1%.

RESULTS

The single common coding variant rs1042579 was not associated with incident VTE. Sixteen rare variants were classified as qualifying and included in collapsing analysis. Seven individuals with VTE compared to 24 individuals without VTE carried one qualifying variant. Cox multivariate regression analysis adjusted for age, sex, body mass index, systolic blood pressure, smoking and alcohol consumption, rs6025, rs1799963, and the top two eigenvectors from a principal components analysis showed a hazard ratio of 3.0 (95% confidence interval 1.4-6.3) for the rare qualifying variants. The distributions of qualifying variants in THBD showed a difference for individuals with and without incident VTE indicating a possible position effect.

CONCLUSIONS

Rare qualifying THBD variants were associated with VTE, suggesting that rare variants in THBD contribute to development of VTE.

Classic Thrombophilias and Thrombotic Risk Among Middle-Aged and Older Adults: A Population-Based Cohort Study

Background

Five classic thrombophilias have been recognized: factor V Leiden (rs6025), the prothrombin G20210A variant (rs1799963), and protein C, protein S, and antithrombin deficiencies. This study aimed to determine the thrombotic risk of classic thrombophilias in a cohort of middle‐aged and older adults.

Methods and Results

Factor V Leiden, prothrombin G20210A and protein‐coding variants in the PROC (protein C), PROS1 (protein S), and SERPINC1 (antithrombin) anticoagulant genes were determined in 29 387 subjects (born 1923–1950, 60% women) who participated in the Malmö Diet and Cancer study (1991–1996). The Human Gene Mutation Database was used to define 68 disease‐causing mutations. Patients were followed up from baseline until the first event of venous thromboembolism (VTE), death, or Dec 31, 2018. Carriership (n=908, 3.1%) for disease‐causing mutations in the PROC, PROS1, and SERPINC1 genes was associated with incident VTE: Hazard ratio (HR) was 1.6 (95% CI, 1.3–1.9). Variants not in Human Gene Mutation Database were not linked to VTE (HR, 1.1; 95% CI, 0.8–1.5). Heterozygosity for rs6025 and rs1799963 was associated with incident VTE: HR, 1.8 (95% CI, 1.6–2.0) and HR, 1.6 (95% CI, 1.3–2.0), respectively. The HR for carrying 1 classical thrombophilia variant was 1.7 (95% CI, 1.6–1.9). HR was 3.9 (95% CI, 3.1–5.0) for carriers of ≥2 thrombophilia variants.

Conclusions

The 5 classic thrombophilias are associated with a dose‐graded risk of VTE in middle‐aged and older adults. Disease‐causing variants in the PROC, PROS1, and SERPINC1 genes were more common than the rs1799963 variant but the conferred genetic risk was comparable with the rs6025 and rs1799963 variants.

MTHFR C677T (rs1801133) genetic polymorphism is associated with development risk of essential hypertension in the Turkish population

Background

Hypertension is a serious condition that is spread worldwide and may lead to severe complications such as heart attack, stroke, hypertensive retinopathy, and renal failure. Although some genetic and environmental risk factors are known to play a role in the etiology of hypertension, like most of the other multi-factorial diseases, its etiology is yet to be fully elucidated. Our study aimed to investigate the effects of methylenetetrahydrofolate reductase (MTHFR) C677T (rs1801133) and A1298C (rs1801131), factor V Leiden (FVL) G1691A (rs6025), and prothrombin (PT) G20210A (rs1799963) genetic polymorphisms on the development risk of essential hypertension and level of blood pressure in hypertensive patients.

Results

The frequency of the homozygous polymorphic TT genotype for the MTHFR C677T polymorphism was significantly higher in male hypertensive patients than in the male control group (27% vs 6.3%, p = 0.028). The rate of the variant T allele for the MTHFR C677T polymorphism was also significantly higher in male hypertensive patients compared to male healthy controls (51.4% vs 21.9%, p = 0.0004). There was no difference among hypertensive patients and healthy controls regarding the frequencies of MTHFR A1298C, FVL G1691A and PT G20210A polymorphisms. In addition, we found no difference between genotype groups regarding systolic and diastolic blood pressure levels in hypertensive patients.

Conclusions

Homozygous polymorphic TT genotype and variant T allele for the MTHFR C677T polymorphism may be considered as a risk factor for the development of essential hypertension in the Turkish male population.

A new decade awaits sticky platelet syndrome: where are we now, how do we manage and what are the complications?

INTRODUCTION

Sticky platelet syndrome is a less known platelet function disorder with a familiar occurrence and likely genetic background. Clinically, it is characterized by an increased risk of venous and arterial thromboembolic events and obstetric placenta-mediated complications. The increased aggregation after low-dose ADP and/or epinephrine is its distinctive laboratory feature. Though described for almost 40 years, several issues regarding its etiology, involved pathomechanisms, genetic background, optimal diagnostic and treatment approach remain controversial.

AREAS COVERED

The work aims to summarize published studies, the actual definition of the syndrome, and point out its drawbacks. A literature search on Medline, Embase, and archives from EHA congresses was performed (terms: 'sticky platelet syndrome' - 'platelet hyperreactivity' - 'platelet hyperaggregability'). The authors added in their unpublished data. The introductory overview of the present understanding is followed by the discussion of the pathophysiologic, diagnostic, and therapeutic problems.

EXPERT OPINION

Despite the growing evidence provided by case reports and series, the lack of robust studies limits the decision-making on diagnostics and management. The diagnostic issues, particularly the standardization of light transmission aggregometry, represent the crucial problem for the broader acceptance of the syndrome.

Thrombotic risk determined by protein C receptor (PROCR) variants among middle-aged and older adults: a population-based cohort study

BACKGROUND

The protein C (PC) anticoagulant system has a key role in maintaining hemostatic balance. One missense (Ser219Gly) variant in the protein C receptor (PROCR) was associated with venous thromboembolism (VTE) in genome-wide association studies.

OBJECTIVES

This study aimed to determine the thrombotic risk of rare and common PROCR variants in a large population-based cohort of middle-aged and older adults.

PATIENTS/METHODS

The exonic sequence of PROCR was analyzed for the Ser219Gly variant and other qualifying variants in 28,794 subjects (born 1923-1950, 60% women) without previous VTE, who participated in the Malmö Diet and Cancer study (1991-1996). Incidence of VTE was followed up until 2018. Qualifying variants were defined as loss-of-function or non-benign (PolyPhen-2) missense variants with minor allele frequencies (MAF) < 0.1%.

RESULTS

Resequencing identified 36 PROCR variants in the study population (26,210 non-VTE exomes and 2584 VTE exomes), 11 synonymous, 22 missense and three loss-of-function variants. Kaplan-Meier analysis of the known Ser219Gly variant (rs867186) showed that homozygosity for this variant increased the risk of disease whereas heterozygosity showed no effect. Cox multivariate regression analysis revealed an adjusted hazard ratio of 1.5 (95%CI 1.1-2.0). Fifteen rare variants were classified as qualifying and were included in collapsing analysis (burden test and SKAT-O). They did not contribute to risk. However, a Arg113Cys missense variant (rs146420040; MAF=0.004) showed an increased VTE risk (HR=1.3; 95%CI 1.0-1.9).

CONCLUSIONS

Homozygosity for the Ser219Gly variant and a previously identified functional PROCR variant (Arg113Cys) was associated with VTE. Other variants did not contribute to VTE.

Today's view of hereditary thrombophilia

Venous thromboembolism (VTE) is still a serious medical problem with the non-decreasing incidence of new cases despite prophylaxis in risky situations. It is a multifactorial disease, in which the hereditary component is also significantly involved. The aim of the current research is to search for new polymorphisms that are involved in thrombogenesis in addition to classical thrombophilia (deficiency of natural coagulation inhibitors and FVL and FII prothrombin mutations). The article provides an overview of the results of already performed genome-wide association studies of VTE and their use for the calculation of the so-called polygenic risk score, which could be used for individualized prevention of VTE after standardization of the method.

Familial Segregation of Venous Thromboembolism in Sweden: A Nationwide Family Study of Heritability and Complex Segregation Analysis

Background

This is the first nationwide segregation analysis that aimed to determine whether familial venous thromboembolism (VTE) is attributable to inheritance and/or shared environment, and the possible mode of inheritance.

Methods and Results

The Swedish Multi‐Generation Register was linked to the Swedish patient register for the period 1964 to 2015. Three generational families of Swedish‐born individuals were identified. Heritability was examined using Falconer regression. Complex segregation analysis was conducted using the Statistical Analysis for Genetic Epidemiology software (version 6.4, 64‐bit Linux). Among the 4 301 174 relatives from 450 558 pedigrees, 177 865 (52% women) individuals were affected with VTE. VTE occurred in 2 or more affected relatives in 61 217 (13.6%) of the pedigrees. Heritability showed age and sex dependence with higher heritability for men and young individuals. In 18 933 pedigrees, VTE occurred only in the first generation and was not inherited. Segregation analysis was performed in the remaining 42 284 pedigrees with inherited VTE and included 939 192 individuals. Prevalence constraints were imposed in the models to allow for the selection of the pedigrees analyzed. The sporadic nongenetic model could be discarded. The major‐type‐only model, with a correlation structure compatible with some polygenic effects, was the preferred model. Among the Mendelian models, the mixed codominant (plus polygenic) model was preferred.

Conclusions

This nationwide segregation analysis of VTE supports a genetic cause of the familial aggregation of VTE. Heritability was higher for men and younger individuals, suggesting a Carter effect, in agreement with a multifactorial threshold inheritance.

Genetic-guided pharmacotherapy for venous thromboembolism: a systematic and critical review of economic evaluations

Despite the known contributions of genes, genetic-guided pharmacotherapy has not been routinely implemented for venous thromboembolism (VTE). To examine evidence on cost-effectiveness of genetic-guided pharmacotherapy for VTE, we searched six databases, websites of four HTA agencies and citations, with independent double-reviewers in screening, data extraction, and quality rating. The ten eligible studies, all model-based, examined heterogeneous interventions and comparators. Findings varied widely; testing was cost-saving in two base-cases, cost-effective in four, not cost-effective in three, dominated in one. Of 22 model variables that changed decisions about cost-effectiveness, effectiveness/relative effectiveness of the intervention was the most frequent, albeit of poor quality. Studies consistently lacked details on the provision of interventions and comparators as well as on model development and validation. Besides improving the reporting of interventions, comparators, and methodological details, future economic evaluations should examine strategies recommended in guidelines and testing key model variables for decision uncertainty, to advise clinical implementations.

Cis-Segregation of c.1171C>T Stop Codon (p.R391*) in SERPINC1 Gene and c.1691G>A Transition (p.R506Q) in F5 Gene and Selected GWAS Multilocus Approach in Inherited Thrombophilia

Inherited thrombophilia (e.g., venous thromboembolism, VTE) is due to rare loss-of-function mutations in anticoagulant factors genes (i.e., SERPINC1, PROC, PROS1), common gain-of-function mutations in procoagulant factors genes (i.e., F5, F2), and acquired risk conditions. Genome Wide Association Studies (GWAS) recently recognized several genes associated with VTE though gene defects may unpredictably remain asymptomatic, so calculating the individual genetic predisposition is a challenging task. We investigated a large family with severe, recurrent, early-onset VTE in which two sisters experienced VTE during pregnancies characterized by a perinatal in-utero thrombosis in the newborn and a life-saving pregnancy-interruption because of massive VTE, respectively. A nonsense mutation (CGA > TGA) generating a premature stop-codon (c.1171C>T; p.R391*) in the exon 6 of SERPINC1 gene (1q25.1) causing Antithrombin (AT) deficiency and the common missense mutation (c.1691G>A; p.R506Q) in the exon 10 of F5 gene (1q24.2) (i.e., FV Leiden; rs6025) were coinherited in all the symptomatic members investigated suspecting a cis-segregation further confirmed by STR-linkage-analyses [i.e., SERPINC1 IVS5 (ATT)_5–18, F5 IVS2 (AT)_6–33 and F5 IVS11 (GT)_12–16] and SERPINC1 intragenic variants (i.e., rs5878 and rs677). A multilocus investigation of blood-coagulation balance genes detected the coexistence of FV Leiden (rs6025) in trans with FV HR2-haplotype (p.H1299R; rs1800595) in the aborted fetus, and F11 rs2289252, F12 rs1801020, F13A1 rs5985, and KNG1 rs710446 in the newborn and other members. Common selected gene variants may strongly synergize with less common mutations tuning potential life-threatening conditions when combined with rare severest mutations. Merging classic and newly GWAS-identified gene markers in at risk families is mandatory for VTE risk estimation in the clinical practice, avoiding partial risk score evaluation in unrecognized at risk patients.

Epidemiology and Genetics of Venous Thromboembolism and Chronic Venous Disease

Venous disease is a term that broadly covers both venous thromboembolic disease and chronic venous disease. The basic pathophysiology of venous thromboembolism and chronic venous disease differ as venous thromboembolism results from an imbalance of hemostasis and thrombosis while chronic venous disease occurs in the setting of tissue damage because of prolonged venous hypertension. Both diseases are common and account for significant mortality and morbidity, respectively, and collectively make up a large health care burden. Despite both diseases having well-characterized environmental components, it has been known for decades that family history is an important risk factor, implicating a genetic element to a patient's risk. Our understanding of the pathogenesis of these diseases has greatly benefited from an expansion of population genetic studies from pioneering familial studies to large genome-wide association studies; we now have multiple risk loci for each venous disease. In this review, we will highlight the current state of knowledge on the epidemiology and genetics of venous thromboembolism and chronic venous disease and directions for future research.

Prevalence of thrombophilia-associated genetic risk factors in blood donors of a regional hospital in southern Brazil

Introduction

Thromboembolic events occur due to an imbalance in the hemostasis and some factors associated with this condition can be inherited. In order to evaluate the frequency of genotypes considered to be common hereditary risk factors for thrombophilia associated with venous thrombosis (g.1691G > A and g.20210G > A) and hyperhomocysteinemia (g.677C > T and g.1298A > C), samples from voluntary healthy blood donors at the Hospital de Clínicas de Porto Alegre were tested.

Methods

We examined 325 blood samples from blood donors collected from October 2017 to July 2018. Blood was collected on filter paper and the DNA was extracted for single nucleotide polymorphisms (SNPs) analysis using the qualitative real time polymerase chain reaction.

Results

The calculated frequencies of each genetic variant in heterozygosity were 4% for the FV gene (g.1691G > A), 4% for the F2 gene (g.20210G > A) and 42% and 39% for methylenetetrahydrofolate reductase (MTHFR), g.677C > T and g.1298A > C, respectively. Only the genetic variants of MTHFR were found in homozygosity, with frequencies of 14% and 6% (g.677C > T and g.1298A > C), respectively.

Discussion

Altogether, these results describe the frequencies of genetic variants associated with venous thrombosis and hyperhomocysteinemia in the analyzed group and are important to enhance our current knowledge about the genetic profiles of Brazilian blood donors.

Prevalence of the Factor V Leiden Mutation Arg534Gln in Western Region of Saudi Arabia: Functional Alteration and Association Study With Different Populations

The rare Gln534 (Factor V Leiden; FVL) allele (1:169,519,049 T>C) is associated with an increased risk of venous thrombosis. The purpose of this study was to measure the prevalence of Factor V Leiden mutation in thrombophilia patients with deep vein thrombosis. Also, we investigated the functional and structural characteristics of this mutation p.(Arg534Gln) to be examined the cumulative impact on venous thrombosis risk as well correlated with different populations by Genome Wide Association Studies (GWAS). A total of 108 patients with idiopathic deep vein thrombosis were examined for Factor V Leiden gene mutation. Our preliminary data show that about 10% of patients were detected with the heterozygous and homozygous form of the Factor V Leiden mutation. An association analysis confirmed that the Factor V SNP variant (rs6025) was highly associated (P-value 4.91 x10-^ -39) with an increased risk of venous thrombosis. Also, we found that the recognized SNP was important among HapMap populations. Our results indicated that among the 3 populations (Asian, African, and American) studied, this association was highest in the African population based on the r(2) significant threshold (P-value 5e-190). In addition, this mutation was located at the domain F5/8 type A 2, which can disturb this domain and abolish its function. Because of aspartic acid nearby wild type position as form in the salt bridge due to this discharge will disturb the ionic interaction made by the wild type residue Arg534. This residue was not found to be in contact with other domains of which the function was known. However, contact with other molecules or domains (THPH2: MIM: 188055) were still possible and might be affected by this mutation that may cause thrombophilia due to activated protein C resistance.