Health-related quality of life and physical activity in Nordic patients with moderate haemophilia A and B (the MoHem study).

INTRODUCTION: The impact of moderate haemophilia on health-related quality of life (HRQoL) and physical activity (PA) is not well known. In previous studies, persons with factor VIII/factor IX activity (FVIII/FIX:C) below 3 IU/dL were associated with a more severe bleeding phenotype than predicted. AIM: To explore HRQoL and PA in patients with moderate haemophilia A (MHA) and B (MHB). METHODS: A cross-sectional, multicentre study covering patients with MHA and MHB in Sweden, Finland, and Norway. HRQoL was assessed with the EuroQoL 5-Dimensions (EQ-5D) form and PA with the International Physical Activity Questionnaire among participants aged ≥15 years. RESULTS: We report on 104 patients aged 15-84 years from the MoHem study. Overall, EQ-5D utility was .85 (median) (Q1-Q3 0.73-1.0) with corresponding visual analogue scale (VAS) 80 (70-90), which were similar regardless of treatment modality, FVIII/FIX:C, and MHA or MHB. Pain and mobility were most frequently affected dimensions. Utility (r = -.54), VAS (r = -.42), and PA (r = -.32) correlated negatively with arthropathy (HJHS). Only patients aged 41-50 years displayed lower utility (p = .02) and VAS (p < .01) than the Norwegian population norm. Patients on prophylaxis aged 35-54 years reported higher PA than those treated on-demand (p = .01). CONCLUSION: Haemophilic arthropathy had negative impact on HRQoL and PA in Nordic patients with moderate haemophilia. Middle-aged patients captured lower utility and VAS than observed in the general population. Tailored prophylaxis and improved joint health may influence positively on HRQoL and PA also in moderate haemophilia.

Plasma protein and venous thromboembolism: prospective cohort and mendelian randomisation analyses.

We conducted cohort and Mendelian randomisation (MR) analyses to examine the associations of circulating proteins with risk of venous thromboembolism (VTE) to provide evidence basis for disease prevention and drug development. Cohort analysis was performed in 11 803 participants without baseline VTE. Cox regression was used to estimate the associations between 257 proteins and VTE risk. A machine-learning model was constructed to compare the importance of identified proteins and traditional risk factors. Genetic association data on VTE were obtained from a genome-wide meta-analysis (26 066 cases and 624 053 controls) and FinnGen (14 454 cases and 294 700 controls). The cohort analysis, including 353 incident VTE cases diagnosed during a 6.6-year follow-up, identified 21 proteins associated with VTE risk after false discovery rate correction. The machine-learning model indicated that body mass index and von Willebrand factor (vWF) made the same as well as most of the contributions to the overall model prediction. MR analysis found that genetically predicted levels of vWF, SERPINE1 (plasminogen activator inhibitor 1, known as PAI-1), EPHB4 (ephrin type-B receptor 4), TYRO3 (tyrosine-protein kinase receptor TYRO3), TNFRSF11A (tumour necrosis factor receptor superfamily member 11A), and BOC (brother of CDO) were causally associated with VTE risk.

No difference in quality of life between persons with severe haemophilia A and B.

INTRODUCTION: Good health-related quality of life (HRQoL) is an important goal in the treatment of persons with haemophilia B (PwHB). Studies focusing on this population are limited, however, and data are insufficient. AIM: To assess the HRQoL in PwHB and to compare this to data on persons with haemophilia A (PwHA), as well as to evaluate the impact of joint health on HRQoL and to identify areas of insufficient care. METHODS: The B-NORD study enrolled persons with severe haemophilia B and matched controls with haemophilia A. HRQoL was assessed using the EQ-5D-3L questionnaire and joint health using Haemophilia Joint Health Score 2.1 (HJHS). RESULTS: The EQ-5D-3L was completed by 63 PwHB and 63 PwHA. Mobility problems were reported by 46% of PwHB and 44% of PwHA, pain/discomfort by 62% and 56%, and anxiety/depression by 33% and 17%, respectively. No significant difference was observed between PwHA and PwHB in EQ-5D profiles, level sum score, EQ-5D index (PwHB mean .80, PwHA mean .83, p = .24), or EQ VAS score (PwHB: mean 70, PwHA: mean 77, p = .061). Linear regression adjusted for age demonstrated that an increase in HJHS score was associated with a significant decrease in both EQ-5D index (B -.003, R2 .22) and EQ VAS score (B -.37, R2 .17). CONCLUSION: Despite the majority of patients being treated with prophylaxis, impaired HRQoL was reported in both PwHB and PwHA. No differences in HRQoL were found between the two groups. Impaired joint health had a significant negative impact on HRQoL.

Association of ABO blood groups with venous thrombosis recurrence in middle-aged patients: insights from a weighted Cox analysis dedicated to ambispective design.

BACKGROUND: In studies of time-to-events, it is common to collect information about events that occurred before the inclusion in a prospective cohort. When the studied risk factors are independent of time, including both pre- and post-inclusion events in the analyses, generally referred to as relying on an ambispective design, increases the statistical power but may lead to a selection bias. In the field of venous thromboembolism (VT), ABO blood groups have been the subject of extensive research due to their substantial effect on VT risk. However, few studies have investigated their effect on the risk of VT recurrence. Motivated by the study of the association of genetically determined ABO blood groups with VT recurrence, we propose a methodology to include pre-inclusion events in the analysis of ambispective studies while avoiding the selection bias due to mortality. METHODS: This work relies on two independent cohorts of VT patients, the French MARTHA study built on an ambispective design and the Dutch MEGA study built on a standard prospective design. For the analysis of the MARTHA study, a weighted Cox model was developed where weights were defined by the inverse of the survival probability at the time of data collection about the events. Thanks to the collection of information on the vital status of patients, we could estimate the survival probabilities using a delayed-entry Cox model on the death risk. Finally, results obtained in both studies were then meta-analysed. RESULTS: In the combined sample totalling 2,752 patients including 993 recurrences, the A1 blood group has an increased risk (Hazard Ratio (HR) of 1.18, p = 4.2 × 10-3) compared with the O1 group, homogeneously in MARTHA and in MEGA. The same trend (HR = 1.19, p = 0.06) was observed for the less frequent A2 group. CONCLUSION: The proposed methodology increases the power of studies relying on an ambispective design which is frequent in epidemiologic studies about recurrent events. This approach allowed to clarify the association of ABO blood groups with the risk of VT recurrence. Besides, this methodology has an immediate field of application in the context of genome wide association studies.

Causal effect of renal function on venous thromboembolism: a two-sample Mendelian randomization investigation.

Whether renal function is causally associated with venous thromboembolism (VTE) is not yet fully elucidated. We conducted a two-sample Mendelian randomization (MR) study to determine the causal effect of renal function, measured as estimated glomerular filtration rate (eGFR), on VTE. Single-nucleotide polymorphisms associated with eGFR were selected as instrumental variables at the genome-wide significance level (p < 5 × 10-8) from a meta-analysis of 122 genome-wide association studies including up to 1,046,070 individuals. Summary-level data for VTE were obtained from the FinnGen consortium (6913 VTE cases and 169,986 non-cases) and UK Biobank study (4620 VTE cases and 356,574 non-cases). MR estimates were calculated using the random-effects inverse-variance weighted method and combined using fixed-effects meta-analysis. Genetically predicted decreased eGFR was significantly associated with an increased risk of VTE in both FinnGen and UK Biobank. For one-unit decrease in log-transformed eGFR, the odds ratios of VTE were 2.93 (95% confidence interval (CI) 1.25, 6.84) and 4.46 (95% CI 1.59, 12.5) when using data from FinnGen and UK Biobank, respectively. The combined odds ratio was 3.47 (95% CI 1.80, 6.68). Results were consistent in all sensitivity analyses and no horizontal pleiotropy was detected. This MR-study supported a casual role of impaired renal function in VTE.

Impaired Fibrinolysis in the Antiphospholipid Syndrome.

The pathogenesis of the antiphospholipid syndrome (APS) is complex and involves the persistent presence of antiphospholipid antibodies (aPL) in the bloodstream causing a prothrombotic condition. aPL induce excessive activation of the endothelium, monocytes, and platelets in consort with aberrations in hemostasis/clotting, fibrinolytic system, and complement activation. Impaired fibrinolysis has been found in APS patients with thrombotic as well as obstetric manifestations. Increased levels of plasminogen activator inhibitor-1 and thrombin-activatable fibrinolysis inhibitor, together with the presence of aPL against annexin-2, tissue-type plasminogen activator, and plasminogen contribute to the compromised fibrinolytic activity in these patients. Furthermore, unfavorably altered fibrin morphology, less amenable to fibrinolysis, has been proposed as a novel prothrombotic mechanism in APS. This review aims to summarize the present knowledge of the mechanisms involved in impaired fibrinolysis in APS patients. We also present a case from clinical practice as an illustration of fibrinolysis impairment in APS patients from a real-life setting.

Haemophilia early arthropathy detection with ultrasound and haemophilia joint health score in the moderate haemophilia (MoHem) study.

INTRODUCTION: Detection of early arthropathy is crucial for the management of haemophilia, but data on moderate haemophilia are limited. Therefore, we evaluated joint health and treatment modalities in Nordic patients with moderate haemophilia A (MHA) and B (MHB). AIM: To explore and compare the Haemophilia Early Arthropathy Detection with Ultrasound (HEAD-US) and Haemophilia Joint Health Score (HJHS) to detect early arthropathy in moderate haemophilia. METHODS: A cross-sectional, multicentre study covering Nordic patients with MHA and MHB. Arthropathy was evaluated by HEAD-US and HJHS 2.1. RESULTS: We assessed 693 joints in 118 patients. HEAD-US scores (medians [interquartile ranges]) were as follows: elbows 0 points (0-0), knees 0 (0-0) and ankles 0 (0-1). Respectively, by HJHS: elbows 0 (0-1), knees 0 (0-1) and ankles 0 (0-1). Cartilage (14%) and bone (13%) were most commonly affected by HEAD-US. Frequent HJHS findings were crepitus on motion in knees (39%), and loss of flexion (23%) and extension (13%) in ankles. HEAD-US correlated strongly with HJHS (elbows r = .70, knees r = .60 and ankles r = .65), but 24% had discordant scores. Joints with HJHS zero points, 5% captured HEAD-US ≥1 point. Moreover, 26% had HJHS findings without HEAD-US pathology. Notably, 31% of knees had crepitus on motion and normal HEAD-US. CONCLUSION: Overall, the joints attained low scores implying good joint health. HEAD-US correlated strongly with HJHS. In 5%, HEAD-US detected subclinical pathology. Crepitus on motion was frequently reported despite normal HEAD-US, thus not necessarily reflecting arthropathy. HEAD-US therefore improves the joint assessment in moderate haemophilia.

Treatment outcomes in persons with severe haemophilia B in the Nordic region: The B-NORD study.

INTRODUCTION: Data on outcome in persons with haemophilia B (PwHB) are limited and mainly extrapolated from studies of haemophilia A (HA). AIM: To characterize treatment outcomes in persons with severe HB in the Nordic region, with a focus on joint health, compared with matched controls with HA. METHODS: PwHB attending haemophilia centres in Denmark, Finland, Norway and Sweden were enrolled and matched with controls with HA. Joint assessment using Haemophilia Joint Health Score (HJHS) and ultrasound according to Haemophilia Early Arthropathy Detection protocol (HEAD-US) was conducted. Adherence was evaluated using the Validated Haemophilia Regimen Treatment Adherence Scale (VERITAS). RESULTS: Seventy-nine males with HB, with median age of 30 years (range 1-75), were enrolled. Eleven patients (14%) had a history of or current inhibitor. Twenty-nine PwHB (37%) reported joint bleeds during the prior year, and 35% had previously undergone joint surgery. Ninety-five per cent were on prophylaxis, and 70% used recombinant concentrates, with a median factor consumption of 3,900 IU/kg/year for standard half-life products. Only two patients had a VERITAS score corresponding to 'non-adherence'. Joint health, assessed with HJHS, showed a significant lower score among PwHB compared with HA controls, explained by a difference in the 18-49 age group, without observed differences in older or younger subgroups. The HEAD-US scores were overall low. CONCLUSION: The Nordic cohort of PwHB is well treated by prophylaxis, but the goal of zero bleeds for all is not reached. Our findings suggest that patients with severe HB suffer from a milder arthropathy than patients with severe HA.

Anti-inflammatory diet and venous thromboembolism: Two prospective cohort studies.

BACKGROUND AND AIMS: Inflammation has been revealed to facilitate thrombogenesis and to increase the risk of venous thromboembolism (VTE). However, limited data are available on the association between the anti-inflammatory diet and incident VTE. We conducted a cohort analysis to examine this association and to further examine whether this association is modified by smoking status, a trigger of systemic inflammation. METHODS AND RESULTS: We used data from two cohorts including 81,507 middle-aged and older Swedish adults without previous VTE at baseline. An empirically validated anti-inflammatory diet index (AIDI), based on 12 foods with anti-inflammatory potential and 5 foods with pro-inflammatory potential, was employed to estimate the anti-inflammatory potential of diet. Hazard ratios (HRs), with corresponding 95% confidence intervals (CIs), of VTE were estimated by Cox proportional hazards regression models. During a mean follow-up of 17.8-years, 5241 VTE cases were diagnosed. Compared with individuals in the lowest quartile of the AIDI (score ≤4), those in the highest quartile (score ≥8) had a 9% (95% CI, 0-17%) lower risk of VTE. The inverse association was observed in current and past smokers (HR between the two extreme quartiles, 0.80, 95% CI, 0.70-0.91) but not in never smokers (HR, 1.03, 95% CI, 0.91-1.17). French fries (HR per serving, 1.33, 95% CI, 1.06, 1.67) but no other foods included in AIDI was associated with VTE. CONCLUSION: The study suggests that a consumption of foods with high anti-inflammatory potential may play a role in the prevention of VTE in smokers.

Joint health and treatment modalities in Nordic patients with moderate haemophilia A and B - The MoHem study.

INTRODUCTION: The prevalence of arthropathy in moderate haemophilia A (MHA) and B (MHB) is not well known. AIM: We evaluated joint health in Nordic patients in relation to their treatment modality. METHODS: A cross-sectional, multicentre study covering MHA and MHB in Sweden, Finland and Norway. Arthropathy was evaluated by ultrasound (HEAD-US) and Haemophilia Joint Health Score (HJHS). RESULTS: We report on 145 patients: median age 28 years (IQR 13-52) and 61% MHA. Baseline factor VIII/factor IX activity (FVIII/FIX:C) was 2 IU/dL (median) (IQR 2-4): lower for MHB (2 IU/dL, IQR 1-2) than MHA (3 IU/dL, IQR 2-4) (P < .01). Eighty-five per cent of MHA and 73% MHB had a history of haemarthrosis (P = .07). Age at first joint bleed was lower for MHA (5 years [median], IQR 3-7) than MHB (7 years, IQR 5-12) (P = .01). Thirty-eight per cent received prophylaxis, started at median 10 years of age (IQR 4-24). Median joint bleeds and serious other bleeds during the last 12 months were both zero (IQR 0-1). Total HEAD-US captured 0/48 points (median) (IQR 0-2) and HJHS 4/120 points (IQR 1-10) with strong correlation between them (r = .72). FVIII/FIX: C ≤ 3 IU/dL was associated with higher HJHS (P = .04). Fifteen per cent had undergone orthopaedic surgery. CONCLUSION: The current joint health in Nordic moderate haemophilia patients was rather good, but a subgroup had severe arthropathy. FVIII/FIX: C ≤ 3 IU/dL and MHA were associated with a more severe bleeding phenotype. We suggest primary prophylaxis to all patients with FVIII/FIX:C ≤ 3 IU/dL.

Management of rivaroxaban- or apixaban-associated major bleeding with prothrombin complex concentrates: a cohort study.

There is uncertainty regarding the effectiveness and occurrence of thromboembolic events in patients treated with prothrombin complex concentrates (PCCs) for the management of major bleeding events (MBEs) on rivaroxaban or apixaban. We investigated the effectiveness of PCCs given for the management of MBEs in patients on rivaroxaban or apixaban. Between 1 January 2014 and 1 October 2016, we prospectively included patients on rivaroxaban or apixaban treated with PCCs for the management of MBEs. The effectiveness of PCCs was assessed by using the International Society of Thrombosis and Hemostasis Scientific and Standardization Subcommittee criteria for the assessment of the effectiveness of major bleeding management. The safety outcomes were thromboembolic events and all-cause mortality within 30 days after treatment with PCCs. A total of 84 patients received PCCs for the reversal of rivaroxaban or apixaban due to a MBE. PCCs were given at a median (interquartile range) dose of 2000 IU (1500-2000 IU). Intracranial hemorrhage (ICH) was the most common site of bleeding requiring reversal (n = 59; 70.2%), followed by gastrointestinal bleeding in 13 (15.5%) patients. Management with PCCs was assessed as effective in 58 (69.1%) patients and ineffective in 26 (30.9%) patients. Most patients with ineffective hemostasis with PCCs had ICH (n = 16; 61.5%). Two patients developed an ischemic stroke, occurring 5 and 10 days after treatment with PCC. Twenty-seven (32%) patients died within 30 days after a MBE. The administration of PCCs for the management of MBEs associated with rivaroxaban or apixaban is effective in most cases and is associated with a low risk of thromboembolism. Our findings are limited by the absence of a control group in the study.

PDGFB, a new candidate plasma biomarker for venous thromboembolism: results from the VEREMA affinity proteomics study.

There is a clear clinical need for high-specificity plasma biomarkers for predicting risk of venous thromboembolism (VTE), but thus far, such markers have remained elusive. Utilizing affinity reagents from the Human Protein Atlas project and multiplexed immuoassays, we extensively analyzed plasma samples from 2 individual studies to identify candidate protein markers associated with VTE risk. We screened plasma samples from 88 VTE cases and 85 matched controls, collected as part of the Swedish "Venous Thromboembolism Biomarker Study," using suspension bead arrays composed of 755 antibodies targeting 408 candidate proteins. We identified significant associations between VTE occurrence and plasma levels of human immunodeficiency virus type I enhancer binding protein 1 (HIVEP1), von Willebrand factor (VWF), glutathione peroxidase 3 (GPX3), and platelet-derived growth factor ß (PDGFB). For replication, we profiled plasma samples of 580 cases and 589 controls from the French FARIVE study. These results confirmed the association of VWF and PDGFB with VTE after correction for multiple testing, whereas only weak trends were observed for HIVEP1 and GPX3. Although plasma levels of VWF and PDGFB correlated modestly (ρ ∼ 0.30) with each other, they were independently associated with VTE risk in a joint model in FARIVE (VWF P < .001; PDGFB P = .002). PDGFΒ was verified as the target of the capture antibody by immunocapture mass spectrometry and sandwich enzyme-linked immunosorbent assay. In conclusion, we demonstrate that high-throughput affinity plasma proteomic profiling is a valuable research strategy to identify potential candidate biomarkers for thrombosis-related disorders, and our study suggests a novel association of PDGFB plasma levels with VTE.

Clinical Implications of Discrepancy between One-Stage Clotting and Chromogenic Factor IX Activity in Hemophilia B.

BACKGROUND: Discrepancy in factor IX activity (FIX:C) between one-stage assay (OSA) and chromogenic substrate assay (CSA) in patients with hemophilia B (PwHB) introduces challenges for clinical management. AIM: To study the differences in FIX:C using OSA and CSA in moderate and mild hemophilia B (HB), their impact on classification of severity, and correlation with genotype. METHODS: Single-center study including 21 genotyped and clinically characterized PwHB. FIX:C by OSA was measured using ActinFSL (Siemens) and CSA by Biophen (Hyphen). In addition, in vitro experiments with wild-type FIX were performed. Reproducibility of CSA was assessed between three European coagulation laboratories. RESULTS: FIX:C by CSA was consistently lower than by OSA, with 10/17 PwHB having a more severe hemophilia type by CSA. OSA displayed a more accurate description of the clinical bleeding severity, compared with CSA. A twofold difference between OSA:CSA FIX:C was present in 12/17 PwHB; all patients had genetic missense variants in the FIX serine protease domain. Discrepancy was also observed with diluted normal plasma, most significant for values below 0.10 IU/mL. Assessment of samples with low FIX:C showed excellent reproducibility of the CSA results between the laboratories. CONCLUSION: FIX:C was consistently higher by OSA compared with the CSA. Assessing FIX:C by CSA alone would have led to diagnosis of a more severe hemophilia type in a significant proportion of patients. Our study suggests using both OSA and CSA FIX:C together with genotyping to classify HB severity and provide essential information for clinical management.

A genome-wide association study identifies KNG1 as a genetic determinant of plasma factor XI Level and activated partial thromboplastin time.

OBJECTIVE: Elevated plasma levels of coagulation factor XI (FXI) are implicated in the pathogenesis of venous thromboembolism and ischemic stroke, and polymorphisms in the F11 gene are associated both with risk of venous thromboembolism and an elevated plasma FXI level. METHODS AND RESULTS: Here, we report the first hypothesis-free genome-wide genetic analysis of plasma FXI levels. Two genome-wide significant loci were detected in the family-based Genetic Analysis of Idiopathic Thrombophilia 1 cohort: one located in the kininogen 1 gene (KNG1) (rs710446; P=7.98 × 10(-10)) and one located in the structural F11 gene (rs4241824; P=1.16 × 10(-8)). Both associations were replicated in a second population-based Swedish cohort. A significant effect on KNG1 mRNA expression was also seen for the 2 most robustly FXI-associated single nucleotide polymorphisms located in KNG1. Furthermore, both KNG1 single nucleotide polymorphisms were associated with activated partial thromboplastin time, suggesting that FXI may be the main mechanistic pathway by which KNG1 and F11 influence activated partial thromboplastin time and risk of thrombosis. CONCLUSIONS: These findings contribute to the emerging molecular basis of venous thromboembolism and, more importantly, help in understanding the biological regulation of a phenotype that has proved to have promising therapeutic properties in relation to thrombosis.

Ultra-processed food intake and incident venous thromboembolism risk: Prospective cohort study.

BACKGROUND & AIMS: Ultra-processed food (UPF) intake has been associated with multiple health outcomes, but data on the association between UPF intake and venous thromboembolism (VTE) risk are lacking. We conducted this study to examine the association between UPF intake and the risk of incident VTE. METHODS: This prospective cohort study was based on 186,323 participants free of baseline VTE from the UK Biobank. UPF intake was assessed by 24-h recall questionnaires. Data on incident VTE came from the nationwide inpatient and primary care datasets and the death registry. Cox proportional hazards regression was used to estimate the association between UPF intake and incident VTE risk. Multiplicative interactions and stratified analyses by age, sex, and body mass index were performed. RESULTS: During a 10.5-year (median) follow-up, 4235 incident VTE cases were diagnosed. After adjusting for covariates, the hazard ratio of VTE among individuals with the highest quintile of UPF intake was 1.05 (95% confidence interval [CI] 0.94, 1.17) for UPF in servings, 1.12 (95% CI 1.01, 1.24) in grams, 1.10 (95% CI 1.00, 1.22) in grams %, 1.21 (95% CI 1.10, 1.33) in energy, and 1.15 (95% CI 1.05, 1.27) in energy % compared to those in the lowest quintile. Age, sex, and body mass index did not modify the associations (Pinteraction > 0.05). CONCLUSIONS: Higher UPF intake was associated with a moderately increased risk of VTE.

Anti-inflammatory diet and incident peripheral artery disease: Two prospective cohort studies.

BACKGROUND & AIMS: Systemic inflammation plays a role in peripheral artery disease (PAD), and therefore, an anti-inflammatory diet may reduce PAD risk. We examined the association between the anti-inflammatory diet and PAD risk by smoking status, a trigger of systemic inflammation. METHODS: The study was based on two cohorts of 82 295 Swedish adults aged 45-83 years (38 823 women from Swedish Mammography Cohort and 45 472 men from Cohort of Swedish Men). An anti-inflammatory diet index (AIDI; 0-17 scores) was used to estimate the anti-inflammatory potential of diet. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs). RESULTS: Over a median 22-year (interquartile range 7.5 years) follow-up period, 3413 PAD cases were ascertained. Compared with individuals in the lowest quartile of the AIDI (score ≤4), the HR of PAD for those in the highest quartile (score ≥8) was 0.84 (95% CI, 0.74-0.94). The inverse association was observed in current and past smokers but not in never smokers. The HR of PAD comparing extreme quartiles of the AIDI was 0.67 (95% CI, 0.53-0.86) in current smoker, 0.78 (95% CI, 0.63-0.97) in past smoker, and 1.00 (95% CI, 0.82-1.23) in never smokers. Among foods included in AIDI, high consumption of breakfast cereals, chocolate, red wine, and olive/canola oil, and low consumption of processed red meat and organ meats were associated with low PAD risk. CONCLUSIONS: The study suggests that adherence to a diet with high anti-inflammatory potential may lower PAD risk, especially in smokers.

Plasma Phospholipid Fatty Acids and Risk of Venous Thromboembolism: Mendelian Randomization Investigation.

Circulating fatty acids may affect thrombosis but epidemiological data on the associations between fatty acids and risk of venous thromboembolism (VTE) are limited and conflicting. We conducted a Mendelian randomization study to examine the causal associations of 10 circulating fatty acids with VTE risk. Genetic variants strongly associated with ten fatty acids and without linkage disequilibrium were selected as instrumental variables from the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium. Genetic associations for VTE and its subtypes were obtained from the International Network Against Venous Thrombosis Consortium (30,234 cases and 172,122 controls) and the FinnGen study (11,288 VTE cases and 254,771 controls). Estimates from the two data sources were combined. Per standard deviation increase in genetically predicted fatty acid levels, the combined odds ratio (OR) of VTE was 0.88 (95% confidence interval [CI] 0.84-0.92) for α-linolenic acid, 0.92 (95% CI 0.90-0.95) for linoleic acid, 0.85 (95% CI 0.78-0.92) for palmitoleic acid, 0.77 (95% CI 0.77-0.84) for oleic acid, 1.16 (95% CI 1.10-1.23) for eicosapentaenoic acid, 1.10 (95% CI 1.06-1.14) for docosapentaenoic acid, 1.06 (95% CI 1.04-1.08) for arachidonic acid, and 1.19 (95% CI 1.11-1.28) for stearic acid. Genetically predicted levels of docosahexaenoic acid or palmitoleic acid were not associated with VTE risk. Four and eight out of ten genetically predicted fatty acid levels were associated with risk of pulmonary embolism and deep vein thrombosis, respectively. This study suggests that strategies targeting at fatty acids may act as prevention approaches for VTE.

Markers of neutrophil activation and neutrophil extracellular traps in diagnosing patients with acute venous thromboembolism: A feasibility study based on two VTE cohorts.

BACKGROUND: Venous thromboembolism (VTE) diagnosis would greatly benefit from the identification of novel biomarkers to complement D-dimer, a marker limited by low specificity. Neutrophil extracellular traps (NETs) have been shown to promote thrombosis and could hypothetically be used for diagnosis of acute VTE. OBJECTIVES: To assess the levels of specific markers of neutrophil activation and NETs and compare their diagnostic accuracy to D-dimer. METHODS: We measured plasma levels of neutrophil activation marker neutrophil elastase (NE), the NET marker nucleosomal citrullinated histone H3 (H3Cit-DNA) and cell-free DNA in patients (n = 294) with suspected VTE (pulmonary embolism and deep vein thrombosis) as well as healthy controls (n = 30). A total of 112 VTE positive and 182 VTE negative patients from two prospective cohort studies were included. RESULTS: Higher levels of H3Cit-DNA and NE, but not cell-free DNA, were associated with VTE. Area under receiver operating curves (AUC) were 0.90 and 0.93 for D-dimer, 0.65 and 0.68 for NE and 0.60 and 0.67 for H3Cit-DNA in the respective cohorts. Adding NE and H3Cit-DNA to a D-dimer based risk model did not improve AUC. CONCLUSIONS: Our study demonstrates the presence of neutrophil activation and NET formation in VTE using specific markers. However, the addition of NE or H3Cit-DNA to D-dimer did not improve the discrimination compared to D-dimer alone. This study provides information on the feasibility of using markers of NETs as diagnostic tools in acute VTE. Based on our findings, we believe the potential of these markers are limited in this setting.

Factor IX antibodies and tolerance in hemophilia B in the Nordic countries - The impact of F9 variants and complications.

INTRODUCTION: The development of inhibitory antibodies (inhibitors) in persons with hemophilia B (PwHB) causes significant morbidity. Data on the impact of the F9 variant and immune tolerance induction (ITI) outcome are limited. The aim of this study was to investigate the presence of neutralizing and non-neutralizing antibodies (NNA) in severe hemophilia B (HB) and to evaluate ITI outcome and complications in relation to the pathogenic F9 variant. MATERIALS AND METHODS: Persons with severe HB in the Nordic countries were enrolled and information on F9 variants, inhibitors, ITI and complications were collected. Analyses of anti-FIX antibodies with a fluorescence-immunoassay (xFLI) and an ELISA method were conducted. RESULTS: Seventy-nine PwHB were enrolled. Null variants were seen in 33 (42 %) PwHB and 12 (15 %) had a current or former inhibitor. Eleven (92 %) of the inhibitor patients had experienced allergic manifestations and three (25 %) nephrotic syndrome. Of 10 PwHB with at least one ITI attempt, eight (80 %) were considered tolerant at enrolment. Immunosuppression was included in seven of eight successful or partially successful attempts. Five PwHB had at least one ITI failure before a successful or partially successful ITI. No NNA could be identified. CONCLUSION: A high proportion of severe F9 gene defects among persons with severe HB in the Nordic countries may explain the observed relatively high prevalence of inhibitors. ITI success was independent of the F9 variant and attained despite allergic manifestations and previous ITI failures. Inclusion of immunosuppression tentatively enhances the chances of ITI success. No NNA were observed.