Minimal interference of concizumab with standard clinical coagulation laboratory assays - An in vitro study.

INTRODUCTION: Non-factor replacement therapies are emerging as prophylactic treatment options in haemophilia A or B (HA/HB) with and without inhibitors. Concizumab is an anti-tissue factor pathway inhibitor (TFPI) monoclonal antibody preventing factor (F)Xa inhibition and enhancing thrombin generation. Based on experience with other non-factor therapies and extended half-life products, there is a focus on potential interference with common clinical coagulation assays used to monitor patients treated with concizumab. AIM: To evaluate the impact of concizumab on standard clinical coagulation assays. METHODS: Plasma samples (normal, HA/HB with/without inhibitors) in the presence/absence of added concizumab (250-16,000 ng/mL) were analysed in clinical assays including activated partial thromboplastin time (aPTT), prothrombin time (PT), FVIII and FIX one-stage clot and chromogenic substrate assay, assays for detecting FVIII or FIX inhibitors and other assays for coagulation factors. RESULTS: Concizumab did not impact PT assays, but resulted in a small shortening of aPTT (up to 5 s in haemophilia plasma and 0.4 s in normal plasma). Concizumab had no, or only a minor impact on FVIII and FIX activity assays or Bethesda inhibitor assays. FXI and FXII activity in normal plasma, as measured by single factor aPTT-based assay, was significantly increased in the presence of concizumab (+11% each). This was also the case for FVII and FX measured by PT-based assays using plasma with 25% of FVII or FX (+64% and +22%, respectively). CONCLUSION: The presence of concizumab did not, or only slightly, influence the outcome of standard clinical coagulation assays relevant for HA and HB.

Methods for anti-factor VIII antibody levels in haemophilia A patients - validation of a multiplex immunoassay and comparability with assays measuring non-neutralising and neutralising antibodies (inhibitors).

INTRODUCTION: The development of neutralising (inhibitors) and non-neutralising antibodies (NNAs) is a complication to factor replacement therapy in haemophilia. The diagnostic methods available lack standardisation, have high inter-laboratory variation, and false-negative as well as false-positive results may affect treatment. Both functional inhibitors and NNAs may be detected with higher reproducibility, sensitivity and specificity using the immunological Luminex xMAP-based fluorescence-immunoassay (xFLI). AIM: Validation of our xFLI and comparability with enzyme-linked immunosorbent assay (ELISA) and chromogenic Nijmegen-Bethesda assay (CBA) for anti-FVIII antibodies in haemophilia A (HA) patients. METHODS: The xFLI method was developed with full-length and B-domain deleted factor coupled to magnetic beads, optimised and validated for performance characteristics. Comparability with ELISA and CBA was evaluated in HA patient samples (n = 112), serial samples in six inhibitor patients and reference interval and decision-limits in healthy donors (n = 44). RESULTS: The intra- and inter-assay precision (CV%) for the xFLI method was below 6% and detection limit (LLOQ) .084 ng/mL (NovoEight). All ELISA-positive samples were positive with either Advate or NovoEight. Additionally, 10.7%-14.3% were xFLI-positive and ELISA-negative. All but one CBA-positive sample was above 3SD with xFLI; one was between 2 and 3SD. 29.1% were xFLI-positive and CBA negative. The overall concordance between xFLI and ELISA was 82.1% and xFLI and CBA 77.9%. CONCLUSION: The anti-FVIII antibody xFLI method is adaptable to clinical practice and more sensitive and reproducible than ELISA and CBA. Actual NNA titers are determined to both full-length and B-domain deleted FVIII. The xFLI is thus valuable for confirmation of all anti-FVIII antibodies.

Antiphospholipid antibodies in patients with myocardial infarction with and without obstructive coronary arteries.

BACKGROUND: Recent studies demonstrate that prothrombotic antiphospholipid antibodies (aPL) are overrepresented in patients with myocardial infarction (MI) due to coronary artery disease (MICAD). However, it is not known whether aPL differ between the two subsets of MI: MICAD and MI with nonobstructive coronary arteries (MINOCA). OBJECTIVES: To determine whether aPL are associated with MINOCA or MICAD, or with hypercoagulability as assessed by activated protein C-protein C inhibitor (APC-PCI) complex. METHODS: Well-characterized patients with MINOCA (n = 98), age- and gender-matched patients with MICAD (n = 99), and healthy controls (n = 100) were included in a cross-sectional case-control study. Autoantibodies (IgA/G/M) targeting cardiolipin and ß2 glycoprotein-I and specific nuclear antigens were analyzed by multiplexed bead technology. The concentration of APC-PCI was determined as a measure of hypercoagulability by an immunofluorometric sandwich assay. RESULTS: Both prevalence and titers of aPL of the IgG isotype (anti-cardiolipin and/or anti-ß2 glycoprotein-I) were higher in patients with MINOCA and MICAD than in controls. aPL IgG positivity was twice as frequent among patients with MICAD than MINOCA (11% vs. 6%, nonsignificant). We observed no group differences regarding aPL IgA/M or antibodies targeting specific nuclear antigens. Levels of APC-PCI were elevated in aPL IgG-positive compared to aPL IgG-negative MICAD patients. CONCLUSIONS: aPL IgG, but not IgA/M, are enriched particularly in patients with MICAD but also in patients with MINOCA, as compared to controls. Interestingly, signs of hypercoagulability-measured by increased levels of the APC-PCI complex-were present in aPL IgG-positive MICAD patients, indicating an association with functional disturbances of the coagulation system.

Evaluation of the Atellica COAG 360 coagulation analyzer in a specialized coagulation laboratory.

BACKGROUND: Diagnosis of bleeding disorders includes correct analysis of coagulation factors VIII, IX, XI, XII, XIII, II, V, VII, and X and von Willebrand antigen and activity. The aim of this study was to evaluate the analytical performance of the Atellica COAG 360 analyzer in a specialized coagulation laboratory with focus on specific coagulation parameters involved in the diagnosis of bleeding disorders. METHODS: Verification included assessment of precision, reference interval, and method comparison according to local guidelines. For FVIII (Chromogenix) and FIX (Rossix), extended verifications were performed with additional assessment of linearity, detection limit, and comparability to BCS-XP. RESULTS: The precision was below 5% (normal levels) and below 10% (abnormal levels) and either improved or similar when compared to expected target values from a BCS-XP. The locally established reference range agreed well (≥80% of measured values within manufacturer's assigned ranges) for most of the methods. The lower limit of quantification was calculated to below 0.01 IU/ml for FVIII chromogenic (Chromogenix) and FIX chromogenic (Rossix), both with acceptable linearity. Bland-Altman analyses revealed generally good agreement between Atellica COAG 360 and BCS-XP in the determination of coagulation parameters, and differences between the two instruments did not result in any diagnostic change. CONCLUSIONS: The results of the evaluation show that the Atellica COAG 360 analyzer performs as expected to target values and equivalent to BCS-XP for the diagnosis of bleeding disorders in a specialized coagulation laboratory providing service to a hemophilia treatment center (HTC).

Validation of factor VIII activity for monitoring standard and extended half-life products and correlation to thrombin generation assays.

INTRODUCTION: Monitoring replacement therapy with standard and extended half-life (EHL) products is challenging, since one-stage assay (OSA) and chromogenic substrate assay (CSA) results may differ significantly. Recent recommendations include local validation of each new product with recovery within 20-30%, depending on activity level. AIM: To validate factor VIII (FVIII) activity for monitoring products in clinical use on Atellica Coag and to correlate it with thrombin generation. METHODS: Plasma samples spiked with Advate® , Elocta® , Adynovi® , Nuwiq® , NovoEight® and Afstyla® (0.05, 0.20, 0.50 and 0.80 IU/ml) were analysed using Atellica Coag 360 with CSA-1 (Coatest SP) and CSA-2 (FVIII chromogenic), and OSA (Actin FS). Thrombin generation was performed using two thrombin generation assays (TGA-1 (Thrombinoscope) and TGA-2 (Technothrombin). RESULTS: All products at levels above 0.05 IU/ml, except Adynovi, showed acceptable recovery using CSA-1, whereas measurements using CSA-2 gave more results outside the target level. All products, except Afstyla, showed acceptable recovery using OSA. Correlation between CSA-1 and OSA was excellent (r2 =1.0) with biases of 6-3​2%, depending on FVIII product. A clear dose-response was seen for all thrombin generation parameters and products using both methods, except at low levels for lag time using TGA-1. With CSA-1 as an independent variable, the correlations to thrombin peak (measured with TGA-2) were good (r2  = .8-.9). CONCLUSION: Our data revealed good correlation and acceptable bias between CSA and OSA using our sets of reagents, methods and analyser in spiked samples. Thrombin generation gave good correlation to CSA-1 factor activity and is a possible complement to factor activity assays.

Clinical utility and impact of the use of the chromogenic vs one-stage factor activity assays in haemophilia A and B.

Treatment of haemophilia A/B patients comprises factor VIII (FVIII) or factor IX (FIX) concentrate replacement therapy, respectively. FVIII and FIX activity levels can be measured in clinical laboratories using one-stage activated partial thromboplastin time (aPTT)-based clotting or two-stage chromogenic factor activity assays. We discuss strengths and limitations of these assays, providing examples of clinical scenarios to highlight some of the challenges associated with their current use for diagnostic and monitoring purposes. Substantial inter-laboratory variability has been reported for one-stage assays when measuring the activity of factor replacement products due to the wide range of currently available aPTT reagents, calibration standards, factor-deficient plasmas, assay conditions and instruments. Chromogenic activity assays may avoid some limitations associated with one-stage assays, but their regulatory status, perceived higher cost, and lack of laboratory expertise may influence their use. Haemophilia management guidelines recommend the differential application of one or both assays for initial diagnosis and disease severity characterisation, post-infusion monitoring and replacement factor potency labelling. Efficient communication between clinical and laboratory staff is crucial to ensure application of the most appropriate assay to each clinical situation, correct interpretation of assay results and, ultimately, accurate diagnosis and optimal and safe treatment of haemophilia A or B patients.

Evaluation of a standardized protocol for thrombin generation using the calibrated automated thrombogram: A Nordic study.

INTRODUCTION: The thrombin generation assay-calibrated automated thrombogram (TGA-CAT) method is used to measure the overall coagulation capacity in plasma. However, the method is still considered to be a research tool, mainly because of its' lack of standardization. AIM: Our study aimed to further raise the standardization level for the TGA-CAT method by evaluating a detailed standardization protocol and three reference plasmas' (RP)s ability to normalize results. METHODS: Six Nordic centres participated in the study, and with input from all centres a detailed laboratory standardization protocol based on the TGA-CAT manual of the manufacturer was established. Three types of plasma, hypo-,normal and hypercoagulable plasma were assessed. Three commercial lyophilized RPs were used for normalization of data. All samples were aliquoted at the Malmö centre and sent frozen at -20˚C to participating centres. RESULTS: Before normalization, all results under all testing conditions showed inter-laboratory coefficient of variability of 10% or lower except for endogenous thrombin potential (12%) and peak (14%) in hypo-plasma with 1 pmol/L tissue factor as starting agent. Successful normalization, improving variability in results, was obtained with two of the three evaluated RPs (HemosIL RP and Affinity RP). CONCLUSION: With our standardization concept, we were able to produce TGA-CAT results as robust as standard coagulation assays used in the routine laboratories. Normalization with HemosIL RP may be considered in populations with low or unknown coagulability, while when analysing plasma samples from populations where hypercoagulability is known or suspected, normalization with Affinity RP may be preferred.

The Coagulopathy of Acute Type A Aortic Dissection: A Prospective, Observational Study.

OBJECTIVE: To evaluate the hemostatic system in patients undergoing surgery for acute type A aortic dissection (ATAAD) compared with those undergoing elective aortic procedures. DESIGN: This was a prospective, observational study. SETTING: The study was performed at a single university hospital. PARTICIPANTS: Twenty-five patients with ATAAD were compared with 20 control patients undergoing elective surgery of the ascending aorta or the aortic root. INTERVENTIONS: No interventions were performed. MEASUREMENTS AND MAIN RESULTS: Platelet count and levels of fibrinogen, D-dimer, prothrombin time/international normalized ratio, activated partial thromboplastin time, and antithrombin were analyzed perioperatively and compared between the 2 groups. Patients with ATAAD had lower preoperative levels of platelets (188 [156-217] × 109/L v 221 [196-240] × 109/L; p = 0.018), fibrinogen (1.9 [1.6-2.4] g/L v 2.8 [2.2-3.0] g/L; p = 0.003), and antithrombin (0.81 [0.73-0.94] kIU/L v 0.96 [0.92-1.00] kIU/L; p = 0.003) and significantly higher levels of D-dimer (2.9 [1.7-9.7] mg/L v 0.1 [0.1-0.2] mg/L; p < 0.001) and prothrombin time/international normalized ratio (1.15 [1.1-1.2] v 1.0 [0.93-1.0]; p = 0.001). Surgery caused significant changes of the coagulation system in both groups. Intraoperative bleeding volumes were larger in the ATAAD group (2,407 [1,804-3,209] mL v 1,212 [917-1,920] mL; p < 0.001), and patients undergoing ATAAD surgery received significantly more transfusions of red blood cells (2.5 [0.25-4.75] U v 0 [0-2.75] U; p = 0.022), platelets (4 [3.25-6] U v 2 [2-4] U; p = 0.002), and plasma (2 [0-4] U v 0 [0-0] U; p = 0.004) compared with the elective group. CONCLUSIONS: This study demonstrates that ATAAD is associated with a coagulopathic state. Surgery causes additional damage to the hemostatic system in ATAAD patients, but also in patients undergoing elective surgery of the ascending aorta or the aortic root.

Identification of novel diagnostic biomarkers for deep venous thrombosis.

The combination of a negative D-dimer and a Wells score can rule out, but not confirm, a diagnosis of deep venous thrombosis (DVT). We aimed to identify new diagnostic biomarkers for DVT and to investigate their relationship with hypercoagulability markers [D-dimer and activated protein C-protein C inhibitor (APC-PCI) complex]. We screened 92 cardiovascular-specific proteins in plasma samples from 45 confirmed DVT patients and 45 age- and sex-matched non-DVT patients selected from a prospective multicentre diagnostic management study (SCORE) by Proseek Multiplex CVDIII96×96 . Plasma levels of 30 proteins were significantly different between DVT and non-DVT patients. After Bonferroni correction, plasma levels of seven proteins: P-selectin, transferrin receptor protein 1, von Willebrand factor, tissue factor pathway inhibitor, osteopontin (OPN), bleomycin hydrolase and ST2 protein remained significantly different. The area under curve (AUC) for these proteins ranged from 0·70 to 0·84. Furthermore, all seven identified proteins were significantly associated with markers of hypercoagulability. A combination of OPN and APC-PCI had the best ability to discriminate DVT from non-DVT patients (AUC = 0·94; sensitivity = 89% and specificity = s84%). In conclusion, we identified multiple proteins associated with markers of hypercoagulability and with a potential to become novel diagnostic biomarkers for DVT.

Germline heterozygous variants in genes associated with familial hemophagocytic lymphohistiocytosis as a cause of increased bleeding.

Familial hemophagocytic lymphohistiocytosis (FHL) is caused by biallelic variants in genes regulating granule secretion in cytotoxic lymphocytes. In FHL3-5, the affected genes UNC13D, STX11 and STXBP2 have further been shown to regulate the secretion of platelet granules, giving rise to compromised platelet function. Therefore, we aimed to investigate platelet degranulation in patients heterozygous for variants in UNC13D, STX11 and STXBP2. During the work-up of patients referred to the Coagulation Unit, Skåne University Hospital, Malmö, Sweden and the Department of Hematology, Rigshospitalet, Copenhagen, Denmark due to bleeding tendencies, 12 patients harboring heterozygous variants in UNC13D, STX11 or STXBP2 were identified using targeted whole exome sequencing. Transmission electron microscopy (TEM) was used to assess the secretion of platelet dense granules following thrombin stimulation. Platelet degranulation, activation and aggregation were further assessed by flow cytometry (FC) and light transmission aggregometry (LTA) with lumi-aggregometry. In total, eight out of twelve (67%) patients showed impaired degranulation by at least one of the assays (TEM, FC and LTA). In the 12 patients, eight different heterozygous variants were identified. One variant was strongly associated with impaired degranulation, while four of the variants were associated with impaired granule secretion to a slightly lesser extent. One additional variant was found in six out of the twelve patients, and was associated with varying degrees of degranulation impairment. Accordingly, six out of the eight (75%) identified variants were associated with impaired platelet degranulation. Our results suggest that heterozygous variants in UNC13D, STX11 and STXBP2 are sufficient to cause platelet secretion defects resulting in increased bleeding.

Warfarin monitoring with viscoelastic haemostatic assays, thrombin generation, coagulation factors and correlations to Owren and Quick prothrombin time.

The anticoagulant warfarin is commonly monitored with prothrombin time (PT). Viscoelastic haemostatic assays (VHA) are primarily used in situations of acute bleeding to guide haemostatic therapy. Much research has focused on VHA monitoring of new oral anticoagulants. However, many patients are still anticoagulated with warfarin and effect of warfarin anticoagulation on VHA is uncertain. The aim of this study was to assess warfarin anticoagulation on three different VHA and compare these findings with prothrombin time (PT), coagulation factor analyses and a thrombin generation assay (TGA). Citrated whole blood was drawn from 80 patients admitted for routine PT-INR Owren. VHA analysis with ROTEM (EXTEM, INTEM and FIBTEM), ReoRox (Fibscreen 1 and 2) and Sonoclot (gbACT+) was performed. Blood was also drawn for plasma analysis with PT (PT-INR Owren and PT Quick), TGA and analysis of factors I, II, VII, IX and X. Extrinsically activated VHA, including ROTEM EXTEM and FIBTEM Clotting Time (CT) and ReoRox Fibscreen1 and 2 clot onset time 1 correlated moderately with PT-INR Owren , with R 0.66-0.71. These four variables were likely to be prolonged above reference interval in patients with prolonged PT-INR Owren >1.2. Two patients with normal ROTEM CTs had Owren PT-INRs >1.5. Warfarin affects extrinsically activated VHA variables of initial clotting. The role of VHA for clinical decision-making in patients planned for invasive procedures, such as spinal/epidural anaesthesia needs further study. None of the recent guidelines on regional anaesthesia include VHA testing to define adequate haemostasis.

Effects of the oral, direct factor Xa inhibitor edoxaban on routine coagulation assays, lupus anticoagulant and anti-Xa assays.

Edoxaban is an oral direct factor Xa inhibitor for prophylaxis and treatment of thromboembolic disorders. The effects on common coagulation assays are clinically valuable information and in certain clinical situations a quick assessment of the anticoagulant is wanted. Our aim was to investigate the effect of edoxaban on routine coagulation methods and evaluate anti-Xa assays, commonly used for other direct factor Xa inhibitors, for estimation of the drug concentration. Edoxaban was spiked to plasma samples from healthy subjects in the concentration range 0-742 µg/L and analyzed using different reagents for activated partial thromboplastin time (APTT) and prothrombin time (PT). Assays for antithrombin, activated protein C resistance, lupus anticoagulant (LA) and chromogenic anti-Xa assays were also included. Edoxaban displayed similar effects in vitro to other oral direct Xa inhibitors. The concentration needed to double the coagulation time varied between assays and reagents; 539-758 µg/L for the APTT and between 329 and 2505 µg/L for the PT. Edoxaban gave false high antithrombin activities in assays based on Xa-inhibition. Two integrated assays for LA, both based on activation with dilute Russell's viper venom, displayed different results. Chromogenic anti-Xa assays displayed linear dose-response curves with edoxaban up to approximately 500 µg/L. In conclusion, therapeutic concentrations of edoxaban variably affect different coagulation assays, and even different reagents within an assay group. In comparison with other oral Xa-inhibitors, the in vitro effects of edoxaban were more similar to rivaroxaban than apixaban. For measurement of edoxaban concentration in plasma, it is possible to use the chromogenic anti-Xa assays.

Procoagulatory changes induced by head-up tilt test in patients with syncope: observational study.

BACKGROUND: Orthostatic hypercoagulability is proposed as a mechanism promoting cardiovascular and thromboembolic events after awakening and during prolonged orthostasis. We evaluated early changes in coagulation biomarkers induced by tilt testing among patients investigated for suspected syncope, aiming to test the hypothesis that orthostatic challenge evokes procoagulatory changes to a different degree according to diagnosis. METHODS: One-hundred-and-seventy-eight consecutive patients (age, 51 ± 21 years; 46% men) were analysed. Blood samples were collected during supine rest and after 3 min of 70° head-up tilt test (HUT) for determination of fibrinogen, von Willebrand factor antigen (VWF:Ag) and activity (VWF:GP1bA), factor VIII (FVIII:C), lupus anticoagulant (LA1), functional APC-resistance, and activated prothrombin time (APTT) with and without activated protein C (C+/-). Analyses were stratified according to age, sex and diagnosis. RESULTS: After 3 min in the upright position, VWF:Ag (1.28 ± 0.55 vs. 1.22 ± 0.54; p < 0.001) and fibrinogen (2.84 ± 0.60 vs. 2.75 ± 0.60, p < 0.001) increased, whereas APTT/C+/- (75.1 ± 18.8 vs. 84.3 ± 19.6 s; p < 0.001, and 30.8 ± 3.7 vs. 32.1 ± 3.8 s; p < 0.001, respectively) and APC-resistance (2.42 ± 0.43 vs. 2.60 ± 0.41, p < 0.001) decreased compared with supine values. Significant changes in fibrinogen were restricted to women (p < 0.001) who also had lower LA1 during HUT (p = 0.007), indicating increased coagulability. Diagnosis vasovagal syncope was associated with less increase in VWF:Ag during HUT compared to other diagnoses (0.01 ± 0.16 vs. 0.09 ± 0.17; p = 0.004). CONCLUSIONS: Procoagulatory changes in haemostatic plasma components are observed early during orthostasis in patients with history of syncope, irrespective of syncope aetiology. These findings may contribute to the understanding of orthostatic hypercoagulability and chronobiology of cardiovascular disease.

Clinical and inflammatory characteristics of the European U-BIOPRED adult severe asthma cohort.

U-BIOPRED is a European Union consortium of 20 academic institutions, 11 pharmaceutical companies and six patient organisations with the objective of improving the understanding of asthma disease mechanisms using a systems biology approach.This cross-sectional assessment of adults with severe asthma, mild/moderate asthma and healthy controls from 11 European countries consisted of analyses of patient-reported outcomes, lung function, blood and airway inflammatory measurements.Patients with severe asthma (nonsmokers, n=311; smokers/ex-smokers, n=110) had more symptoms and exacerbations compared to patients with mild/moderate disease (n=88) (2.5 exacerbations versus 0.4 in the preceding 12 months; p<0.001), with worse quality of life, and higher levels of anxiety and depression. They also had a higher incidence of nasal polyps and gastro-oesophageal reflux with lower lung function. Sputum eosinophil count was higher in severe asthma compared to mild/moderate asthma (median count 2.99% versus 1.05%; p=0.004) despite treatment with higher doses of inhaled and/or oral corticosteroids.Consistent with other severe asthma cohorts, U-BIOPRED is characterised by poor symptom control, increased comorbidity and airway inflammation, despite high levels of treatment. It is well suited to identify asthma phenotypes using the array of "omic" datasets that are at the core of this systems medicine approach.

A nonneutralizing antibody as cause of prothrombin deficiency in a patient with follicular lymphoma.

Acquired inhibitors of blood coagulation are rare but of clinical importance. Prothrombin is a vitamin K-dependent protein, and acquired antibodies toward prothrombin are often associated with the presence of lupus anticoagulant. We describe a previously healthy 70-year-old man presenting with both hemorrhage and thrombosis as well as a prolonged prothrombin time. At arrival at the hospital, he was diagnosed with deep venous thrombosis, and an enlarged lymph node in the left groin was noted (revealed as follicular lymphoma grade 1 by biopsy). Prothrombin activity and antibody titer were followed for 5 months with 15 sampling time points to monitor the treatment outcome of the patient. Diagnostic work-up identified prothrombin deficiency as cause of bleeding. A nonneutralizing calcium-dependent antiprothrombin antibody was found, suspected to increase the clearance of prothrombin, which has previously only occasionally been reported. Lupus anticoagulant was ruled out and thrombosis was judged to be caused by a combination of malignant disease and stagnant venous flow following enlarged lymph nodes in the groin. This report illustrates how investigation of prolonged global coagulation tests, triggered the diagnosis of a rare but critical condition, immune-mediated prothrombin deficiency. The diagnosis is challenging and involves proper differential diagnosis.

[Analysis with viscoelastic hemostatic assays - a guide]. / En guide till koagulationsanalys med viskoelastiska instrument.

Viscoelastic hemostasis analyses (VHA) are a complement in the evaluation of hemostasis in patients with major bleeding. The analysis measures viscoelastic changes in whole blood and the results give an overview of several components of hemostasis. VHA can be used to optimize fibrinogen levels, platelet and plasma substitution. The main clinical evidence supporting this strategy is in trauma, obstetric bleeding, heart and liver surgery, where algorithms based on VHA results facilitate individualized therapy. VHA measurement is of limited value to exclude treatment with anticoagulants and platelet inhibitors. Quality control aspects are also more cumbersome since whole blood with limited sustainability is used. Newer, more automated versions of the instruments have increased the reproducibility. The main advantage of VHA is the fast turn-around time and their role in guiding treatment in an emergency situation with bleeding.

[Factor XIII deficiency - not only a congenital bleeding disorder]. / Koagulationsfaktor XIII ­ inte bara ett kongenitalt blödningsproblem.

Factor XIII (FXIII) cross-links fibrin monomers to strengthen clots. The congenital severe autosomal type of FXIII deficiency with <5 percent of normal FXIII activity is an extremely rare bleeding disorder with <10 cases in Sweden. It often debuts at birth with prolonged umbilical cord bleedings and an increased risk for bleeding throughout life. Patients with severe congenital FXIII deficit have an established FXIII concentrate treatment, both for prophylaxis and at bleeding episodes. Acquired autoantibodies against FXIII are also rare, with high bleeding risks. Quantitative FXIII analyses are only available in few laboratories in Sweden. Sometimes more complex antigen/antibody/gene mutation tests are needed for diagnosis, but these are not available in Sweden. Other acquired FXIII deficiencies can occur in patients with several diseases and during surgery/trauma. Their treatment and diagnostic logistics are less defined. Recent European guidelines on perioperative bleeding have suggested FXIII concentrate treatment.

Infrastructural considerations of implementing gene therapy for hemophilia in the Nordic context.

Background: Despite improvements in hemophilia care, challenges remain, including treatment burden and impaired quality of life. Gene therapy may overcome these. However, its introduction presents a challenge. Objectives: To outline a function-based gene therapy working model describing critical milestones associated with gene therapy handling, administration, and follow-up to facilitate and implement an effective infrastructure for gene therapy introduction. Design: Literature review and consensus discussion among Hemophilia Comprehensive Care centers (HCCCs) in the Nordic region. Methods: Representatives from six HCCCs sought to pinpoint milestones and key stakeholders for site readiness at the pre-, peri-, and post-infusion stages, including authority and genetically modified organism (GMO) product requirements, awareness, medical eligibility, logistics and product handling for infusion, laboratory monitoring, and follow-up. Results: A gene therapy transit map was developed with key stakeholders identified. The approach to prepare the vector will differ between the Nordic centers, but the contracted pharmacy unit will be a key stakeholder. Therefore, a pharmacy checklist for the implementation of gene therapy was developed. For the future, Advanced Therapy Medicinal Product centers will also be implemented. Patients' expectations, commitments, and concerns need to be addressed repeatedly and education of patients and the expanded health-care professionals team will be the key to successful and optimal clinical management. Eligibility testing according to the product's summary of product characteristics and frequent follow-up and monitoring post-infusion according to the World Federation of Hemophilia chart will be crucial. Conclusion: The approach to deliver gene therapy in the Nordic region will differ partly between the hemophilia centers, but the defined road map with checklists for the implementation of this advanced therapy will be applicable to all. The map may also serve as a platform for the use of future GMO product options both within and outside the area of hemophilia.

Implementing gene therapy for hemophilia in the Nordic context Why was this study done? • Despite improvements in hemophilia care, challenges remain including treatment burden and impaired quality of life. • Gene therapy may overcome these challenges. • The introduction of gene therapy presents a challenge in many ways. What did the researchers do? • We, as representatives from six Hemophilia Comprehensive Care Centers in the Nordic region, sought to pinpoint milestones and key stakeholders for site readiness at the pre-, peri- and post-infusion stages, including authority and genetically modified organism (GMO) product requirements, awareness, medical eligibility, logistics and product handling for infusion, laboratory monitoring, plus follow-up. What did the researchers find? • We developed a gene therapy transit map and identified key stakeholders. • The approach to prepare the vector will differ between the Nordic centers, but the pharmacy unit will be a key stakeholder. We therefore developed a pharmacy checklist for the implementation of gene therapy. • For the future, Advanced Therapy Medicinal Product centers will be implemented. • Patients' expectations, commitments and concerns need to be addressed repeatedly. • Education of patients and the expanded health care professionals team will be the key to successful and optimal clinical management. • Eligibility testing according to the product's summary of product characteristics and close follow-up and monitoring post-infusion according to the World Federation of Hemophilia chart will be crucial. • Access to both chromogenic and one-stage factor activity assay results from a specialized coagulation laboratory with a short turn-around time is important. What do the findings mean? • The approach to delivering gene therapy in the Nordic region will differ partly between the hemophilia centers, but the defined road map with checklists for the implementation will be applicable to all. • The map may also serve as a platform for the use of future GMO product options both within and outside the area of hemophilia.

A prospective, controlled study on the utility of rotational thromboelastometry in surgery for acute type A aortic dissection.

To evaluate the hemostatic system with ROTEM in patients undergoing surgery for acute type aortic dissection (ATAAD) using elective aortic procedures as controls. This was a prospective, controlled, observational study. The study was performed at a tertiary referral center and university hospital. Twenty-three patients with ATAAD were compared to 20 control patients undergoing elective surgery of the ascending aorta or the aortic root. ROTEM (INTEM, EXTEM, HEPTEM and FIBTEM) was tested at 6 points in time before, during and after surgery for ATAAD or elective aortic surgery. The ATAAD group had an activated coagulation coming into the surgical theatre. The two groups showed activation of both major coagulation pathways during surgery, but the ATAAD group consistently had larger deficiencies. Reversal of the coagulopathy was successful, although none of the groups reached elective baseline until postoperative day 1. ROTEM did not detect low levels of clotting factors at heparin reversal nor low levels of platelets. This study demonstrated that ATAAD is associated with a coagulopathic state. Surgery causes additional damage to the hemostatic system in ATAAD patients as well as in patients undergoing elective surgery of the ascending aorta or the aortic root. ROTEM does not adequately catch the full coagulopathy in ATAAD. A transfusion protocol in ATAAD should be specifically created to target this complex coagulopathic state and ROTEM does not negate the need for routine laboratory tests.