Abstract: Von Willebrand factor (VWF) is a multimeric glycoprotein essential for primary haemostasis that is produced only in endothelial cells and megakaryocytes. Key to VWF’s function in recruitment of platelets to the site of vascular injury is its multimeric structure. The individual steps of VWF multimer biosynthesis rely on distinct posttranslational modifications at specific pH conditions, which are realized by spatial separation of the involved processes to different cell organelles. Production of multimers starts with translocation and modification of the VWF prepropolypeptide in the endoplasmic reticulum to produce dimers primed for glycosylation. In the Golgi apparatus they are further processed to multimers that carry more than 300 complex glycan structures functionalized by sialylation, sulfation and blood group determinants. Of special importance is the sequential formation of disulfide bonds with different functions in structural support of VWF multimers, which are packaged, stored and further processed after secretion. Here, all these processes are being reviewed in detail including background information on the occurring biochemical reactions.

Abstract: Im Kindesalter werden wie bei Erwachsenen hamorrhagische Diathesen und thrombotische Erkrankungen beobachtet. Die Ursachen sind angeboren oder erworben. Schwerere angeborene Storungen mit Blutungsfolgen manifestieren sich meist im Kleinkindalter, wahrend angeborene thrombophile Storungen meist in Kombination mit zusatzlichen Risikofaktoren das Entstehen von Thrombosen mit Gipfeln im Neugeborenen- und Pubertats- bzw. Adoleszentenalter begunstigen. Zur Beurteilung von Hamostaseparametern in Verbindung mit klinischem Befund ist die Kenntnis einiger kindlicher Besonderheiten, wie die Altersabhangigkeit der Gerinnungswerte, wichtig. Nur so konnen adaquate Therapieentscheidungen getroffen werden.

Abstract: Non-arteritic anterior ischaemic optic neuropathy (NAION) is caused by ischaemia of the optic nerve head. The pathophysiology of NAION is unclear, and no proven effective treatment exists. Patients, methods: We analyzed thrombophilic risk factors and determinants of atherosclerosis and inflammation in 109 consecutive patients and 109 age- and sex-matched volunteers using a case-control design. Results: High levels of fibrinogen (>384 mg/dl; OR 3.2, p = 0.003), factors VIII:C (>183%; OR 2.6, p = 0.02), IX (>153%; OR 2.6, p = 0.026), XI (>142%; OR 3.4, p = 0.006), von Willebrand factor (activity >205%; OR 3.1, p = 0.005; antigen >194%; OR 3.5, p = 0.002), and triglycerides (>228 mg/dl; OR 2.8, p = 0.026), higher platelet counts (>294 000/μl; OR 2.5, p = 0.04), low levels of HDL cholesterol (20 mm/h; OR 4.4, p = 0.003) were associated with NAION. Conclusion: Our findings support the contention of a complex pathogenesis of NAION resulting from the coincidence of proatherogenic, prothrombotic and proinflammatory processes. The alterations described could be causative, side effects, or just coincidental findings.

Abstract: With the aging of the haemophilia population, age related comorbidities become more and more a medical issue. Managing haemophilia patients with cardiovascular disease is a difficult task for many haemophilia-treating physicians. Over the years, insights on prevalence, risk factors and management of cardiovascular disease in haemophilia have improved substantially. It is now recognised that many risk factors, such as hypertension and overweight, occur quite frequently in patients with haemophilia. Several new insights in anticoagulation management of atrial fibrillation and coronary ischaemia in haemophilia have been suggested. This review provides an general overview of the current knowledge of these topics in literature.

Abstract: Chronic hepatitis C virus (HCV) infection causes significant mortality in patients with inherited bleeding disorders, however, data of interferon-free antiviral regimes are scarce in this population. Patients, methods: Real-life data of interferon-free therapies of 18 patients with inherited bleeding disorders and chronic HCV genotype 1 infection (94% male, liver cirrhosis Child A/B n = 4/1). Results: Treatment naive patients were treated for eight weeks with sofosbuvir (SOF)/ledipasvir (n = 3) or for 12 weeks with SOF/ledipasvir (n = 4), SOF/ledipasvir/ribavirin (n = 1), or paritaprevir/r, ombitasvir, dasabuvir (n = 1). Treatment experienced patients without cirrhosis received SOF/ledipasvir (n = 3) or paritaprevir/r, ombitasvir, dasabuvir ± ribavirin (n = 2) for 12 weeks. Re-treated cirrhotic individuals were treated for 24 weeks with SOF/ledipasvir (n = 2) and SOF/daclatasvir (n = 1), or for 12 weeks SOF/simeprevir/1200 mg/d ribavirin (n = 1). Sustained virologic response (SVR-12) was achieved by 17/18 individuals without severe on-treatment side effects. Conclusions: In real-life, HCV-infected patients with inherited bleeding disorders can be effectively and safely treated with interferon-free therapies.

Abstract: Thrombocytosis is a frequent laboratory finding but not a diagnosis. Therefore, elevated platelet counts (>450 x 109/l) require careful diagnostic work-up to differentiate between reactive thrombocytosis (RT), caused by various conditions, and essential thrombocythemia (ET), a myeloproliferative neoplasm (MPN). In either setting, aspirin is widely used in clinical practice. However, RT (even at platelet counts >1000 x 109/l) has never been shown to cause thrombosis or bleeding due to acquired von Willebrand factor defects in association with high platelet counts. Identification of reactive conditions and appropriate therapy of the underlying disorder are most relevant. By contrast to RT, ET and related MPN can be associated with thrombosis and/or hemorrhage. Current recommendations suggest the use of low-dose aspirin in all patients with ET unless contraindicated. However, the strength of this recommendation is weak, i. e. evidence level IIb grade B. A potential benefit of aspirin used for primary thromboprophylaxis in ET is mostly derived from the ECLAP study in polycythemia vera (PV). However, translating study results from PV to ET appears to be highly questionable and may be biased. In the absence of robust data regarding the benefit-risk balance of aspirin in ET, it appears reasonable to stratify patients according to their individual thrombotic and bleeding risk, to restrict the use of aspirin to high-risk categories and patients with microcirculatory disturbances, to test for pharmacological efficacy (COX-1 inhibition; measurement of TXB2), and to modify the aspirin dosing regimen (twice instead of once daily) if required.

Abstract: Since more than 20 years, aspirin is an approved and established first-line antiplatelet medication in cardiovascular prevention. This is partially due to ist unique mode of action which is not shared with any other antiplatelet agent as well by the reliability of its pharmacological efficacy: inhibition of platelet COX-1 and subsequent thromboxane formation in almost every patient. Aspirin acts synergistic with ADP-antagonists in dual antiplatelet therapy of acute coronary syndroms (ACS) and percutaneous coronary interventions (PCI) and is also approved for long-term secondary prevention. Patients with atrial fibrillation are an exception and benefit more from anticoagulants. After the introduction of the new oral anticoagulants (NOACs), i.e. direct inhibitors of factor Xa or thrombin formation, there is a renewed discussion about the role of antiplatelet agents, specifically if additional dual antiplatelet treatment is still necessary for an optimum clinical effect or whether one component, such as aspirin might be skipped in favor of other classes of oral antiplatelet agents, such as ADP-antagonists. The available data are insufficient to recommend this because of a low number of studies and a still uncertain benefit/risk (bleeding) ratio. More research on aspirin as a chemopreventive appears also to be necessary and is going on, in particular in individuals at high-risk for vascular thrombotic diseases (diabetics, preeclampsia, venous thrombembolism).

Abstract: Venous thromboembolism (VTE) in patients with cancer is associated with an increased morbidity and mortality, and its prevention is of major clinical importance. However, the VTE rates in the cancer population vary between 0.5% - 20%, depending on cancer-, treatment- and patient-related factors. The most important contributors to VTE risk are the tumor entity, stage and certain anti-cancer treatments. Cancer surgery represents a strong risk factor for VTE, and medical oncology patients are at increased risk of developing VTE, especially when receiving chemotherapy or immunomodulatory drugs. Also biomarkers have been investigated for their usefulness to predict risk of VTE (e.g. elevated leukocyte and platelet counts, soluble P-selectin, D-dimer, etc.). In order to identify cancer patients at high risk of VTE and to improve risk stratification, risk assessment models have been developed, which contain both clinical parameters and biomarkers. While primary thromboprophylaxis with low-molecular-weight-heparin (LMWH) is recommended postoperatively for a period of up to 4 weeks after major cancer surgery, the evidence is less clear for medical oncology patients. Thromboprophylaxis in hospitalized medical oncology patients is advocated, and is based on results of randomized controlled trials which evaluated the efficacy and safety of LMWH for prevention of VTE in hospitalized medically ill patients. In recent trials the benefit of primary thromboprophylaxis in cancer patients receiving chemotherapy in the ambulatory setting has been investigated. However, at the present stage primary thromboprophylaxis for prevention of VTE in these patients is still a matter of debate and cannot be recommended for all cancer outpatients.

Abstract: The objective of this study was to define fall rates and to identify possible fall risk factors in adult patients with severe haemophilia. Patients, material, methods: 147 patients with severe haemophilia A and B were evaluated using a standardized test battery consisting of demographic, medical and clinical variables and fall evaluation. Results: 41 (27.9 %) patients reported a fall in the past 12 months, 22 (53.7 %) of them more than once. Young age, subjective gait insecurity and a higher number of artificial joints seem to be risk factors for falling. Conclusion: Falls seem to be a common phenomenon in patients with severe haemophilia. Fall risk screening and fall prevention should be implemented into daily practice.

Abstract: The haemophilia treatment centre of the Clinic for Children and Youth Medicine in Jena extends medical care by health-promotion measures, namely: health counselling, adjuvant exercise therapy and school sports. In addition to the regular medical checks at the treatment centre patients are examined regarding physical fitness, joint situation, quality of life in general and disease-specific manner, as well as psycho-social and nutritional behaviour. Findings and medical results of the examinations are integrated into an individual advice on therapy, school sports, and health recommendations. This aimed at strengthening health-related resources and minimizing potential injuries. First long-term evaluation shows an increase of activity behaviour and physical fitness without increasing bleeding rate and maintained joint function. Conclusion: Combining functional prevention diagnostics and individual health counselling shows signs of improved patient’s health knowledge, self-competence and physical fitness.

Abstract: Haemophilia A (HA) is caused by a broad spectrum of different mutation types in the factor VIII gene (F8). In our patient cohort of more than 2600 HA patients as well as in other published studies, the most frequent cause are missense mutations in different F8 exons or the recurrent intron 22 inversion. Some exons and several specific nucleotide positions represent hot spots for point mutations in the examined cohort. About 4 % of cases remain without mutation after routine HA diagnostic methods including inversion PCRs, Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA). Deep intronic mutations cannot be detected by current standard HA diagnostics but have been reported for several genetic disorders. However, next generation sequencing (NGS) of the whole genomic sequence of the F8 gene allows to identify deep intronic variants. Conclusion: In general, NGS provides an effective approach to screen for different HA causing mutation types in the F8 gene.

Abstract: Hepatitis C virus (HCV) represents one of the most common aetiologies of chronic liver disease and causes a major global health burden. Globally an estimated 80 million people are chronically infected, but the majority of whom is still undiagnosed. Prior to the discovery of the virus in 1989 a significant number of patients were exposed and consecutively infected with HCV via contaminated transfusions, as it is a blood-borne disease. Chronic HCV infection pursues a progressive course that ultimately results in the development of cirrhosis, liver failure and hepatocellular carcinoma (HCC), if left untreated. The efficiency and tolerability of therapeutical approaches improved considerably with the development of direct-acting antivirals (DAA). The majority of patients treated with the recommended DAA combinations can be cured, which is reflected in achievement of sustained virological response (SVR). This review is intended to provide guidance in the management of patients with chronic hepatitis C, including recommendations for adequate screening, diagnostic procedures, clinical care, treatment and follow-up strategies.

Abstract: Inhibitor development in haemophilia is a serious complication to treatment with factor concentrates. Since the advent of more pure products, especially developed using recombinant DNA technology, some studies have shown an increased incidence of inhibitors in previously untreated patients (PUPs) receiving recombinant products whereas plasma-derived concentrates sometimes have been claimed to have a protective role, probably due to the content of von Willebrand factor (VWF). In fact, experiments indicate that the VWF may block uptake of factor VIII into macrophages for further processing to the immune system. Also, a competition between VWF and inhibitor binding to the C2 domain of factor VIII has been suggested. Recently, large cohort and surveillance studies have created a vigorous debate about the role of product class for inhibitor development as results have been conflicting. The only randomised prospective study, the SIPPET study, was published in 2016, and substantiated previous reports claiming that plasma derived concentrates give less inhibitors in patients with severe haemophilia A, previously not exposed to factor VIII. The debate will continue.

Abstract: National Patient Registries (NPR) have an important role in the management of haemophilia and other inherited bleeding disorders, representing powerful instruments to support healthcare and research. Computer software to assist the NPR is crucial, as it facilitates the introduction of the data from a national universe that will be centralized and merged into a unique location, thus ensuring a greater reliability and accuracy of the collected data, avoiding duplication of patients. In Portugal, despite the efforts and recognition of the need of a NPR, just recently the protocol for the establishment of the computer software to support the Portuguese National Registry of Haemophilia and other Congenital Coagulopathies (PorR H&CC) was approved. This paper aims to present this newly developed computerized solution, as well as to report the main variables and information that will be available. The development of this application, which includes a set of socio-demographic, clinical and treatment data, was based on the principles of WFH, and the database that supports the NPR, with anonymized data, is operated and maintained in accordance with the Data Protection Law. Currently, the first data are available on the application. Our focus now is to ensure more registries and continuous data entry in order to have complete information on the characterization of the haemophilia patient population in Portugal.

Abstract: The antiphospholipid syndrome (APS) is characterized by venous and/or arterial thrombosis and severe pregnancy morbidity in presence of antiphospholipid antibodies (aPL) While there is compelling evidence that aPL cause the clinical manifestations of APS, the underlying mechanisms are still a matter of scientific debate This is mainly related to the broad heterogeneity of aPL There are three major types of aPL: The first one binds to (anionic) phospholipids, eg cardiolipin, in absence of other factors (cofactor independent aPL) The second type binds to phospholipids only in presence of protein cofactors, eg s2-glycoprotein I (s2GPI) (cofactor dependent aPL) The third type binds to cofactor proteins directly without need for phospholipids It is widely believed that cofactor independent aPL (type 1) are associated with infections and, more importantly, non-pathogenic, while pathogenic aPL belong to the second and in particular to the third type This view, in particular with regard to type 1 aPL, has not been undisputed and novel research data have shown that it is in fact untenable We summarize the available data on the pathogenetic role of aPL and the implications for diagnosis of APS and future research

Abstract: The sequencing of hundreds of thousands of human exomes and hundreds of thousands of whole genomes is providing a progressively accurate and complete catalogue of human genetic variation. The initial studies to use genome wide data to help understand platelet disorders performed genome wide association studies to identify loci linked to variations in blood cell parameters. These studies used normal variation to find corresponding genetic variation. We next wished to investigate the genetic basis of bleeding disorders which may also provide a key to novel genes regulating platelet and haemostatic functions. The BRIDGE consortium (www.bridgestudy.org) is funded by the NIHR and brings together 13 rare disease gene discovery projects. The aim of these projects is to investigate as yet undiagnosed rare inherited diseases and identify the underlying mutational basis. We have used a cluster analysis based on the Human Phenotype Ontology in combination with next generation sequencing techniques to help identify patients with similar phenotypes which we hypothesise will arise from defects in the same gene. Preliminary results validate the clustering approach and have also resulted in a number of novel genes important for normal and pathogenic platelet physiology.

Abstract: Haemophilic arthropathy is a complex multifactorial disorder that poses significant challenges to both the treating haematologist and arthroplasty surgeon. Its pathogenesis is incompletely understood. Recent literature has concentrated on the toxic effects of iron and the characteristic inflammatory synovitis. Discussion of the role of subchondral bleeding in joint damage has been neglected. A case of haemophilic arthropathy with extensive evidence of subchondral bleeding and related osteochondral destruction is presented. Result The relevance of this mechanical pathway in the future management of haemophilic arthropathy is discussed with reference to recent literature. Conclusion Clinicians should consider its importance when deciding whether to manage patients expectantly or with prophylactic factor replacement.

Abstract: Spontaneous intraabdominal hemorrhage is a very rare event even in patients with bleeding disorders like hemophilia. Nevertheless this rare case must be considered in patients with coagulopathies presenting with abdominal pain. Prompt radiologic imaging and surgical consultation are of highest priority. Here we report on a 20-year-old patient with moderate hemophilia A, who underwent emergency laparotomy for a spontaneous idiopathic bleeding of the omentum majus. There are few cases in the literature on this sort of event in patients with hemophilia, who mostly suffer from spontaneous joint bleedings. These patients require an intensive, interdisciplinary perioperative care, involving haematologists, surgeons, radiologists and anesthesists. Finally we discuss, whether an optimized, individually adapted treatment with coagulation factors might possibly have prevented this bleeding event in this patient.

Abstract: The thrombotic-thrombocytopenic purpura (TTP) is an acute, life-threatening disease, characterised by enhanced platelet aggregation, disturbed microcirculation and organ dysfunction. With the currently available treatment (plasma exchange, infusions, corticosteroids) mortality ist still as high as 10–15 %. Recent, pathophysiology-based developments may improve the outcome. The most promising candidates for future treatment of TTP are: rituximab for termination of the autoimmune process, caplacizumab for prevention of platelet-VWF-interaction, and recombinant ADAMTS13 for replacement of the inhibited or missing enzyme.

Abstract: Haemophilia A (FVIII deficiency) and haemophilia B (FIX deficiency) are X-linked inherited bleeding disorders. It is a very rare event to identify both haemophilias in the same patient. So far, only two families with such combination are reported in the literature worldwide supported by genetic background. Patients and methods: Evaluation of clinical data, determination of FVIII and FIX levels and genetic analysis of F8 and F9 genes by direct sequencing. Results: We report on a patient having severe haemophilia B (FIX:C T, p.R75X), whereas F8 gene analysis revealed a point mutation in exon 4 (c.545A>C, p.D182A). The mother of the patient was heterozygous for F8 mutation, but not for F9 mutation suggesting a de novo F9 mutation. Accidentally, further family from Germany with mild Haemophilia A was identified to have the same F8 mutation. F8 Haplotype analysis revealed that the p.D182A mutation most likely represents a founder mutation with common ancestors of the German and the Lithuanian family. Conclusions: Our results confirm the rare event of Haemophilia A and haemophilia B in the same patient originating from two distinct genetic defects in F8 and F9 genes.

Abstract: The maturation and postnatal development of the human coagulation system results in significant and important differences in the coagulation and fibrinolysis of neonates and young children compared to older children and adults. Importantly, these differences, which mostly reflect the immaturity of the neonatal haemostasis system, are functionally balanced. Healthy neonates show no signs of easy bruising or other bleeding diathesis and no increased tendency to thrombosis for any given stimulus compared to adults. Systemic diseases may affect haemostasis, thus predisposing ill neonates to increased risk for haemorrhagic or thrombotic complications. In hospitalized children, neonates have increased risk of developing thrombosis compared to infants and children, mostly associated with the presence of central venous catheter. For diagnosis of haemostasis disorders, diagnostic laboratories processing pediatric samples should use age, analyzer and reagent appropriate reference ranges. Age specific guidelines should be followed for the management of neonates with hemostatic disorders.

Abstract: Vitamin K 2,3-epoxide reductase complex, subunit 1 (VKORC1) is an enzyme essential for the vitamin K cycle. VKORC1 catalyses the reduction of vitamin K 2,3-epoxide to the quinone form of vitamin K and further to vitamin K hydroquinone. The generated vitamin K hydroquinone serves as substrate for the enzyme γ-glutamyl-carboxylase which modifies all vitamin K-dependent proteins, allowing them to bind calcium ions necessary for physiological activity. Vitamin K-dependent proteins include the coagulation factors FII, FVII, FIX, FX, and proteins C, S und Z. Insufficient VKORC1 enzyme activity results in deficiency of the vitamin K-dependent clotting factors leading to haemorrhagic disorders. This phenotype is known as vitamin K clotting factor deficiency type 2 (VKCFD2). Worldwide, only four families of independent origin have been reported with this rare bleeding disorder. Affected family members carry the mutation VKORC1:p.Arg98Trp in homozygous form, the only mutation found so far to be associated with VKCFD2. Now, ten years after the identification of the VKORC1 gene, the molecular pathomechanism of VKCFD2 has been clarified. The Arg98Trp mutation disrupts an ER retention motif of VKORC1 leading to mislocalisation of the protein to outside the endoplasmatic reticulum. In this review, we summarize the clinical data, diagnosis, therapy and molecular pathomechanism of VKCFD2.

Abstract: Blood platelets were the focus of recent issues of this Journal (1, 2). Why do these inconspicuous, small cellular fragments, derived from megakaryocytes in the bone marrow, gain so much attention both in clinical settings and basic science? Platelets contribute essentially to survey the integrity of the vascular system by becoming adherent within milliseconds and by forming platelet aggregates at sites of injured endothelial cells or exposed subendothelial matrix structures (3). Overall, platelets play a pivotal role in hemostasis. However, once stimulated, platelets respond uniformly and do not distinguish between traumatic injury and vascular lesions caused by variety of clinical disorders (4). Thus, under pathological conditions, mechanisms otherwise beneficial for hemostasis and vascular integrity may cause occlusive thrombi and, subsequently, acute ischemic syndromes of the heart, brain and other organ systems (5, 6).

Abstract: The article reviews three recent publications addressing physiological and pathological aspects of platelet granules and release as well as limitations of recent screening tests for diagnosis of non-syndromic inherited δ-storage pool disease (1-3).

Abstract: “Bad news are good news” – this cynical slogan from the media is certainly not true in science and also not applicable to publishers of scientific journals. As Editor-inChief, I am happy to report on several items of good news: • First, the Chair of the GTH Council and Schattauer’s representatives accepted the Editor’s proposal to extend the roster of the Editorial Board. • Second, Johanna Kremer Hovinga, President of the upcoming GTH Meeting in Basel, agreed to become Guest Editor of the Journal’s traditional congress issue (1/2017). • Third, Hämostaseologie – Progress in Haemostasis has maintained its impact factor, which is now 1.547 (for 2015).

Abstract: Afibrinogenemia represents the rarest form of fibrinogen deficiency. Causative missense mutations occur rarely and may improve the understanding of fibrinogen structure and function. Patients and methods The propositus was a 26-year-old Argentinian with afibrinogenemia. FGA, FGB and FGG exons and flanking regions were screened by sequencing and the mutant protein was analyzed in silico. Results A novel missense mutation in the FGB gene (Bbeta Gly272Arg, p.Gly302Arg) was identified. In silico analysis revealed its location in a highly conserved region, which preserves the core fold of the C-terminal beta-chain and is important for proper secretion. A substitution by a positively charged large Arg residue in this area would most likely disturb the core fold by additional interactions with adjacent residues (p.Asp291, p.Asp297, p.Asp311), or by forming of non-native interactions with other proteins, thereby hindering the action of molecular chaperones. Both alternatives would disturb the regular secretion of the beta-chain. Conclusions The novel missense mutation in the FGB gene causes afibrinogenemia most probably by affecting the secretion of the fibrinogen beta-chain.

Abstract: Spontaneous intraabdominal hemorrhage is a very rare event even in patients with bleeding disorders like hemophilia. Nevertheless this rare case must be considered in patients with coagulopathies presenting with abdominal pain. Prompt radiologic imaging and surgical consultation are of highest priority. Here we report on a 20-year-old patient with moderate hemophilia A, who underwent emergency laparotomy for a spontaneous idiopathic bleeding of the omentum majus. There are few cases in the literature on this sort of event in patients with hemophilia, who mostly suffer from spontaneous joint bleedings. These patients require an intensive, interdisciplinary perioperative care, involving haematologists, surgeons, radiologists and anesthesists. Finally we discuss, whether an optimized, individually adapted treatment with coagulation factors might possibly have prevented this bleeding event in this patient.