The impact of JAK2 and MPL mutations on diagnosis and prognosis of splanchnic vein thrombosis: a report on 241 cases. Blood. 2008;111:4922-4929. [PMID: 18250227 DOI: 10.1182/blood-2007-11-125328]

A Clinical Case of Timely Diagnosis and Successful Treatment of Budd-Chiari Syndrome With Fulminant Cytolysis in the Setting of a First-time Diagnosed Myeloproliferative Disease

The article presents a clinical case of peculiarities of clinical manifestations, diagnostic and therapeutic approaches of undiagnosed chronic myeloproliferative disease, on the background of which Budd-Chiari syndrome (BCS) developed. The results of clinical course, examination, and treatment of a patient with BCS as a manifestation of the hidden course of primary myelofibrosis with the presence of somatic mutation (V617F) in Janus-tyrosine kinase-2 (JAK2) gene in myeloid cells are presented. Standard clinical and laboratory examinations, and cytomorphologic and histologic examination of bone marrow were used. The diagnosis of BCS was confirmed by ultrasound (US) Doppler examination of the portal system vessels. Symptomatic therapy resulted in insignificant positive results. The analysis of this clinical case showed that the development of BCS was due to a chronic myeloproliferative disease that was not diagnosed before the development of thrombosis. Hepatic vein thrombosis was accompanied by the development of fulminant cytolytic syndrome. Along with symptomatic therapy, patient K., female, 32 years old, underwent transjugular intrahepatic portosystemic shunting 1 month after the first symptoms of BCS appeared, which contributed to a significant clinical effect. Seven years after the installation of 4 transjugular intrahepatic portosystemic shunts, the patient's condition remains satisfactory. The uniqueness of this clinical case lies in the presence of 2 serious diseases at the same time: myeloproliferative pathology (primary myelofibrosis) JAK2-positive variant and BCS. Timely diagnosis of both hematological diseases and their complication in the form of hepatic vein thrombosis with fulminant cytolytic syndrome allowed timely prescription of adequate treatment with a good clinical response.

Obliteration of liver sinusoids through platelet aggregates associated to extramedullary haematopoiesis in myeloid neoplasms

Herein is reported a series of five patients with myeloid neoplasms presenting hepatic complications in whose liver biopsy revealed obstruction of sinusoids by platelet aggregates associated to liver extramedullary haematopoiesis. Indication of liver biopsies was jaundice, unexplained hepatomegaly or portal hypertension. Haematological disorders were classified according to the World Health Organisation. Molecular profile was established in all cases as well as grade of liver extramedullary haematopoiesis and myelofibrosis. The patients were four men and one woman aged from 50 to 82 years. Two patients had myeloproliferative neoplasm (triple negative primary myelofibrosis and JAK2-mutated essential thrombocytopenia), two patients had unclassifiable myelodysplastic/myeloproliferative neoplasm and one patient had chronic myelomonocytic leukaemia type 1. Liver biopsies revealed platelet aggregates occluding sinusoids in association with extramedullary haematopoiesis grade 1 in one patient, grade 2 in two patients and grade 3 in two patients. Two of these patients presented co-existing liver fibrosis due to chronic alcoholic consumption and ischemic heart failure. These five patients died from 2 to 23 months after liver biopsy due to acute myeloblastic leukaemia (three patients), portal hypertension (one patient) or other causes (acute heart failure). Intrahepatic sinusoidal microthromboses through platelet aggregates might cause portal hypertension or liver deficiency in patients with myeloid neoplasms, independently of JAK2 mutational status and grade of extramedullary haematopoiesis.

Exploring the Molecular Aspects of Myeloproliferative Neoplasms Associated with Unusual Site Vein Thrombosis: Review of the Literature and Latest Insights

Myeloproliferative neoplasms (MPNs) are the leading causes of unusual site thrombosis, affecting nearly 40% of individuals with conditions like Budd-Chiari syndrome or portal vein thrombosis. Diagnosing MPNs in these cases is challenging because common indicators, such as spleen enlargement and elevated blood cell counts, can be obscured by portal hypertension or bleeding issues. Recent advancements in diagnostic tools have enhanced the accuracy of MPN diagnosis and classification. While bone marrow biopsies remain significant diagnostic criteria, molecular markers now play a pivotal role in both diagnosis and prognosis assessment. Hence, it is essential to initiate the diagnostic process for splanchnic vein thrombosis with a JAK2 V617F mutation screening, but a comprehensive approach is necessary. A multidisciplinary strategy is vital to accurately determine the specific subtype of MPNs, recommend additional tests, and propose the most effective treatment plan. Establishing specialized care pathways for patients with splanchnic vein thrombosis and underlying MPNs is crucial to tailor management approaches that reduce the risk of hematological outcomes and hepatic complications.

The molecular landscape of myeloproliferative neoplasms associated with splanchnic vein thrombosis: Current perspective

BCR::ABL1-negative myeloproliferative neoplasms (MPNs) are classically represented by polycythemia vera, essential thrombocythemia, and primary myelofibrosis. BCR::ABL1-negative MPNs are significantly associated with morbidity and mortality related to an increased risk of thrombo-hemorrhagic events. They show a consistent association with splanchnic vein thrombosis (SVT), either represented by the portal, mesenteric or splenic vein thrombosis, or Budd-Chiari Syndrome. SVT is also a frequent presenting manifestation of MPN. MPNs associated with SVT show a predilection for younger women, high association with JAK2V617F mutation, low JAK2V617F variant allele frequency (generally <10 %), and low rates of CALR, MPL, or JAK2 exon 12 mutations. Next-Generation Sequencing techniques have contributed to deepening our knowledge of the molecular landscape of such cases, with potential diagnostic and prognostic implications. In this narrative review, we analyze the current perspective on the molecular background of MPN associated with SVT, pointing as well future directions in this field.

Molecular Mechanisms Underlying Vascular Liver Diseases: Focus on Thrombosis

Vascular liver disorders (VLDs) comprise a wide spectrum of clinical-pathological entities that primarily affect the hepatic vascular system of both cirrhotic and non-cirrhotic patients. VLDs more frequently involve the portal and the hepatic veins, as well as liver sinusoids, resulting in an imbalance of liver homeostasis with serious consequences, such as the development of portal hypertension and liver fibrosis. Surprisingly, many VLDs are characterized by a prothrombotic phenotype. The molecular mechanisms that cause thrombosis in VLD are only partially explained by the alteration in the Virchow's triad (hypercoagulability, blood stasis, and endothelial damage) and nowadays their pathogenesis is incompletely described and understood. Studies about this topic have been hampered by the low incidence of VLDs in the general population and by the absence of suitable animal models. Recently, the role of coagulation imbalance in liver disease has been postulated as one of the main mechanisms linked to fibrogenesis, so a novel interest in vascular alterations of the liver has been renewed. This review provides a detailed analysis of the current knowledge of molecular mechanisms of VLD. We also focus on the promising role of anticoagulation as a strategy to prevent liver complications and to improve the outcome of these patients.

Advances in management of primary myelofibrosis and polycythaemia vera: Implications in clinical practice

Primary myelofibrosis (PMF) and polycythaemia vera (PV) are rare BCR-ABL1-negative myeloproliferative neoplasms, associated with an increased risk of thrombosis, haemorrhagic complications and progression to fibrosis or leukaemia or fibrosis for PV. Both diseases are characterised by biological and clinical heterogeneity, leading to great variability in their management in routine clinical practice. In this review, we present an updated overview of the diagnosis, prognosis and treatment of PMF and PV, and we discuss how our multidisciplinary expert group based across France translates this evidence-based knowledge into routine clinical practice.

Pathological and genomic features of myeloproliferative neoplasms associated with splanchnic vein thrombosis in a single-center cohort

Here, we reviewed clinical-morphological data and investigated mutational profiles by NGS in a single-center series of 58 consecutive MPN-SVT patients admitted to our hospital between January 1979 and November 2021. We identified 15.5% of PV, 13.8% of ET, 34.5% of PMF, 8.6% of SMF and 27.6% of MPN-U. Most cases (84.5%) carried JAK2V617F mutation, while seven patients were characterized by other molecular markers, namely MPL in four and CALR mutations in three cases. NGS was performed in 54 (93.1%) cases: the most frequent additional mutations were found in TET2 (27.8%) and DNMT3A (16.7%) genes, whereas 25 (46.3%) patients had no additional mutation. Cases with JAK2V617F homozygosity had a higher median number of additional mutations than those with low allele burden. More importantly, all cases of leukemic evolution were characterized by a higher median number of co-mutations, and a co-mutational pattern of high-risk lesions, such as truncating mutations of ASXL1, bi-allelic TP53 loss, and CSMD1 mutations. Nevertheless, no difference was found between cases with and without additional somatic mutations regarding fibrotic progression, SVT recurrence, other thrombo-hemorrhagic complications, or death. After a median follow-up of 7.1 years, ten deaths were recorded; fibrotic progression/leukemic evolution was ascertained in one (1.7%) and six (10.3%) patients, respectively, while 22 (37.9%) patients suffered from recurrent thrombosis. In conclusion, our data underline the importance of using NGS analysis in the management of MPN-related SVT as it can support the MPN diagnosis, particularly in "triple-negative" cases, and provide additional information with potential consequences on prognosis and therapeutic strategies.

Budd-Chiari syndrome in myeloproliferative neoplasms: A review of literature

Myeloproliferative neoplasms (MPNs) are defined as clonal disorders of the hematopoietic stem cell in which an exaggerated production of terminally differentiated myeloid cells occurs. Classical, Philadelphia-negative MPNs, i.e., polycythemia vera, essential thrombocythemia and primary myelofibrosis, exhibit a propensity towards the development of thrombotic complications that can occur in unusual sites, e.g., portal, splanchnic or hepatic veins, the placenta or cerebral sinuses. The pathogenesis of thrombotic events in MPNs is complex and requires an intricate mechanism involving endothelial injury, stasis, elevated leukocyte adhesion, integrins, neutrophil extracellular traps, somatic mutations (e.g., the V617F point mutation in the JAK2 gene), microparticles, circulating endothelial cells, and other factors, to name a few. Herein, we review the available data on Budd-Chiari syndrome in Philadelphia-negative MPNs, with a particular focus on its epidemiology, pathogenesis, histopathology, risk factors, classification, clinical presentation, diagnosis, and management.

Myeloproliferative neoplasms and splanchnic vein thrombosis: Contemporary diagnostic and therapeutic strategies

Myeloproliferative neoplasms (MPNs) are the most common etiologies of primary splanchnic vein thrombosis, present in almost forty percent of patients with Budd-Chiari syndrome or portal vein thrombosis. Diagnosis of MPNs can be difficult in these patients because key characteristics, such as elevated blood cell counts and splenomegaly, are confounded by portal hypertension or bleeding complications. In recent years, diagnostic tools have improved to provide more accurate diagnosis and classification of MPNs. Although bone marrow biopsy findings remain a major diagnostic criterion, molecular markers are playing an increasing role not only in diagnosis but also in better estimating prognosis. Therefore, though screening for JAK2V617F mutation should be the starting point of the diagnostic workup performed in all patients with splanchnic vein thrombosis, a multidisciplinary approach is needed to accurately diagnose the subtype of myeloproliferative neoplasm, recommend the useful additional tests (bone marrow biopsy, search for an additional mutation using targeted next-generation sequencing), and suggest the best treatment strategy. Indeed, providing a specific expert care pathway for patients with splanchnic vein thrombosis and underlying myeloproliferative neoplasm is crucial to determine the optimal management to reduce the risk of both hematological and hepatic complications.

Molecular Genetics of Thrombotic Myeloproliferative Neoplasms: Implications in Precision Oncology

Classical BCR-ABL-negative myeloproliferative neoplasms (MPN) include polycythaemia vera, essential thrombocythaemia, and primary myelofibrosis. Unlike monogenic disorders, a more complicated series of genetic mutations are believed to be responsible for MPN with various degrees of thromboembolic and bleeding complications. Thrombosis is one of the early manifestations in patients with MPN. To date, the driver genes responsible for MPN include JAK2, CALR, MPL, TET2, ASXL1, and MTHFR. Affords have been done to elucidate these mutations and the incidence of thromboembolic events. Several lines of evidence indicate that mutations in JAK2, MPL, TET2 and ASXL1 gene and polymorphisms in several clotting factors (GPIa, GPIIa, and GPIIIa) are associated with the occurrence and prevalence of thrombosis in MPN patients. Some polymorphisms within XRCC1, FBG, F2, F5, F7, F12, MMP9, HPA5, MTHFR, SDF-1, FAS, FASL, TERT, ACE, and TLR4 genes may also play a role in MPN manifestation. This review aims to provide an insightful overview on the genetic perspective of thrombotic complications in patients with MPN.

Lessons Learned From a Case of Behcet's Disease Presenting With Fever and Life-Threatening Venous Thromboembolism

Infection mimics pose a challenge in the world of infectious diseases. Fever of unknown origin (FUO) requires careful consideration for a broad range of diagnoses. The answer often lies in a careful history and dedicated clinical examination. A delay in diagnosis can result in greater morbidity for the patient. We present the diagnostic challenges in a patient with an infection mimic, Behcet's disease (BD), who presented with recurrent venous thromboembolism (VTE) and fever of unknown origin (FUO). We present the case of a 53-year-old male of Irish Caucasian ethnicity who presented with a history of fevers and recurrent VTE at a university hospital in Dublin, Ireland. Past medical history includes schistosomiasis, which was treated following a trip to sub-Saharan Africa. Our patient was previously diagnosed with a provoked deep vein thrombosis (DVT). He went on to experience four subsequent episodes of VTE, including DVT, pulmonary embolism (PE), and cerebral venous sinus thrombosis (CVST) while on different forms of anticoagulation. On each of these occasions, there was a concern for sepsis due to fevers > 38°C and a C-reactive protein (CRP) > 200 mg/L. The infection workup included routine laboratory tests, blood and urine cultures, CT of the abdomen and pelvis (CTAP), echocardiogram, and PET-CT, all of which were unrevealing. However, a focused clinical examination revealed evidence of subtle scrotal and oral ulceration, pustulation, and erythema at several sites in his upper limb following venesection and cannulation. In this context, a diagnosis of Behcet's disease was considered. A diagnosis of Behcet's disease can only be confidently made after the exclusion of other potential etiologies. In this case, we had to consider a broad range of infectious (malaria, schistosomiasis, rickettsial disease, and endocarditis) and noninfectious (malignancy, antiphospholipid syndrome (APS), myeloproliferative disorders, and paroxysmal nocturnal hemoglobinuria (PNH)) diseases. A delay in diagnosis comes at the cost of increased morbidity and mortality for the patient. A detailed history and clinical examination are key, in addition to a high index of suspicion. Following the induction of high-dose steroid, our patient is doing very well on maintenance adalimumab. From an anticoagulation perspective, he is warfarinized and has not had any further episodes of VTE.

Rivaroxaban Prophylaxis in Noncirrhotic Portal Vein Thrombosis

BACKGROUND: In patients with noncirrhotic chronic portal vein thrombosis (PVT), the benefit of long-term anticoagulation is unknown. We assessed the effects of rivaroxaban on the risk of venous thromboembolism and portal hypertension-related bleeding in such patients. METHODS: In this multicenter, controlled trial, we randomly assigned patients with noncirrhotic chronic PVT without major risk factors for thrombosis to receive either rivaroxaban 15 mg/day or no anticoagulation. The primary end point was 2-year thrombosis-free survival. Secondary end points included the occurrence of site-specific thromboses and major bleeding events. RESULTS: A total of 111 participants were enrolled in the trial, with a mean age of 50.4±13.2 years; 58% of participants were men. An unplanned interim analysis was requested by the independent data safety monitoring board (DSMB) after 10 thrombotic events occurred. The thrombosis incidence rate was 0 per 100 person-years in the rivaroxaban group and 19.71 per 100 person-years (95% confidence interval, 7.49 to 31.92) in the no anticoagulation group (log-rank P=0.0008) after a median follow-up of 11.8 months. Based on the interim analysis, the DSMB recommended switching patients from the no anticoagulation group to anticoagulation. After a median follow-up of 30.3 months (intraquartile range, 24.3 to 47.8), major bleeding occurred in two patients receiving rivaroxaban and in one patient not receiving anticoagulation. No deaths occurred. CONCLUSIONS: After a median follow-up of 11.8 months, among patients with noncirrhotic chronic PVT without major risk factors for thrombosis, daily rivaroxaban reduced the incidence of venous thromboembolism and did not increase major bleeding events. (Funded by grants from the French Ministry of Health and the Association de Malades des Vaisseaux du foie; ClinicalTrials.gov number, NCT02555111.)

Challenges in managing patients on anticoagulation: Thrombocytopenia, resumption after bleeding and recurrent thrombosis

Prescribing of anticoagulation is increasing worldwide. This is partly reflective of an aging population with cardiovascular comorbidities such as arrhythmias and prosthetic heart valves, alongside improvements in cancer treatments and survival. In this review, we discuss three common challenges faced by clinicians. These concern the management of patients with thrombosis and thrombocytopenia, resumption of anticoagulation in patients with a history of gastrointestinal or intracranial haemorrhage, and how to approach and treat a patient with recurrent thrombosis on anticoagulation. We consider the available evidence including relevant published recommendations and propose practical management suggestions to aid clinicians faced with these dilemmas.

Circulating Endothelial Cell Levels Correlate with Treatment Outcomes of Splanchnic Vein Thrombosis in Patients with Chronic Myeloproliferative Neoplasms

Circulating endothelial cells (CECs) are viable, apoptotic or necrotic cells, identified by CD 146 surface antigen expression, considered a biomarker of thrombotic risk, given their active role in inflammatory, procoagulant and immune processes of the vascular compartment. Growing evidence establishes that CECs are also involved in the pathogenesis of several hematological and solid malignancies. The primary aim of this study was to verify if CEC levels could predict both the course and treatment responses of splanchnic vein thrombosis (SVT), either in patients affected by myeloproliferative neoplasms (MPNs) or liver disease. Thus, a retrospective multicenter study was performed; fifteen patients receiving anticoagulant oral treatment with vitamin k antagonists (VKA) for SVT were evaluated. Nine patients were affected by MPN, and all of them received cytoreduction in addition to anticoagulant therapy; four of these patients had primary myelofibrosis (PMF) and were treated with ruxolitinib (RUX), and one patient with primary myelofibrosis, two patients with essential thrombocythemia (ET), and two patients with polycythemia vera (PV) were treated with hydroxyurea (HU). Six patients affected by liver diseases (three with liver cirrhosis and three with hepatocellular carcinoma) were included as the control group. CECs were assayed by flow cytometry on peripheral blood at specific time points, for up to six months after enrollment. The CEC levels were related to C-reactive protein (CRP) levels, splenic volume reduction, and thrombus recanalization, mainly in MPN patients. In patients with liver cirrhosis (LC) and hepatocellular carcinoma (HCC), for which the mechanism of SVT development is quite different, the relationship between CEC and SV reduction was absent. In conclusion, the CEC levels showed a significant correlation with the extent of venous thrombosis and endothelial cell damage in myeloproliferative neoplasm patients with splanchnic vein thrombosis. Although preliminary, these results show how monitoring CEC levels during cytoreductive and anticoagulant treatments may be useful to improve SVT outcome in MPN patients.

Polycythemia vera: historical oversights, diagnostic details, and therapeutic views

Polycythemia vera (PV) is a relatively indolent myeloid neoplasm with median survival that exceeds 35 years in young patients, but its natural history might be interrupted by thrombotic, fibrotic, or leukemic events, with respective 20-year rates of 26%, 16%, and 4%. Current treatment strategies in PV have not been shown to prolong survival or lessen the risk of leukemic or fibrotic progression and instead are directed at preventing thrombotic complications. In the latter regard, two risk categories are considered: high (age >60 years or thrombosis history) and low (absence of both risk factors). All patients require phlebotomy to keep hematocrit below 45% and once-daily low-dose aspirin, in the absence of contraindications. Cytoreductive therapy is recommended for high-risk or symptomatic low-risk disease; our first-line drug of choice in this regard is hydroxyurea but we consider pegylated interferon as an alternative in certain situations, including in young women of reproductive age, in patients manifesting intolerance or resistance to hydroxyurea therapy, and in situations where treatment is indicated for curbing phlebotomy requirement rather than preventing thrombosis. Additional treatment options include busulfan and ruxolitinib; the former is preferred in older patients and the latter in the presence of symptoms reminiscent of post-PV myelofibrosis or protracted pruritus. Our drug choices reflect our appreciation for long-term track record of safety, evidence for reduction of thrombosis risk, and broader suppression of myeloproliferation. Controlled studies are needed to clarify the added value of twice- vs once-daily aspirin dosing and direct oral anticoagulants. In this invited review, we discuss our current approach to diagnosis, prognostication, and treatment of PV in general, as well as during specific situations, including pregnancy and splanchnic vein thrombosis.

Philadelphia chromosome-negative myeloproliferative neoplasms in younger adults: A critical discussion of unmet medical needs, with a focus on pregnancy

Myeloproliferative neoplasms (MPN) are traditionally regarded as a disease of older adults, though a not negligible fraction of cases occurs at a younger age, including women of childbearing potential. MPN in younger patients, indeed, offer several challenges for the clinical hematologist, that goes from difficulties in reaching a timely and accurate diagnosis to a peculiar thrombotic risk, with a relatively high incidence of thromboses in unusual sites (as the splanchnic veins or the cerebral ones). Moreover, the issue of pregnancy is recently gaining more attention as maternal age is rising and molecular screening are widely implemented, leading to a better recognition of these cases, both before and during pregnancy. In the present work we aim at discussing four clinical topic that we identified as areas of uncertainty or true unmet medical needs in the management of younger patients with MPN, with a particular focus on the topic of pregnancy. For each of these topics, we critically reviewed the available evidence that support treatment decisions, though acknowledging that recommendations in this field are mostly based on expert opinion or derived from guidelines of other clinical conditions that share with MPN a high vascular risk, as antiphospholipid syndrome. Taking into consideration both the lack of evidence-based data and the clinical heterogeneity of MPN, we support an individualized strategy of counseling and management for both young patients and for expectant mother with MPN.

Incidence, characteristics and risk factors of thromboembolic events in East Asian patients with BCR-ABL1 negative myeloproliferative neoplasms

The vascular complications have been a major cause of morbidity and mortality among all subtypes of BCR-ABL1 negative myeloproliferative neoplasms (MPN), but the ethnicity-specific data was limited. We therefore conducted a multi-center retrospective, longitudinal cohort study to evaluate the incidence, characteristics and risk factors of thromboembolic events of MPN patients. Of 256 patients, 27.3% experienced thromboembolic events, majority of which occurred before or within 12 months of MPN diagnosis. The multivariable Cox proportional analyses identified leukocytosis (HR 2.67, 95% CI 1.36-5.24, q = 0.004) and history of thrombosis (HR 9.68, 95% CI 2.00-46.88, q = 0.005) as the risk factors for thromboembolism. In subgroup analysis of polycythemia vera and hemoglobin concentration (HR 1.97, 95% CI 1.28-3.04, q = 0.002) appeared to be a significant risk factor of thrombosis, along with age and thrombosis history. In essential thrombocythemia, severity of the established IPSET score was closely correlated with the frequency of thromboembolic events. In primary myelofibrosis, history of thrombosis was associated with thrombosis events (HR 13.85, 95% CI 1.2-159.5, q = 0.035). Overall survival was worse in patients who experienced thromboembolic events. Our study highlighted the importance of recognizing high risk patients and implementing personalized intervention.

Improving the investigative approach to polycythaemia vera: a critical assessment of current evidence and vision for the future

Polycythaemia vera is a challenging disease to study given its low prevalence and prolonged time-to-event for important clinical endpoints such as thrombosis, progression, and mortality. Although researchers in this space often rise to meet these challenges, there is considerable room for improvement in the analysis of retrospective data, the development of risk-stratification tools, and the design of randomised controlled trials. In this Viewpoint, we review the evidence behind the contemporary approach to risk stratification and treatment of polycythaemia vera. Frameworks for using data more efficiently, constructing more nuanced prognostic models, and overcoming challenges in clinical trial design are discussed.

Cancer-Associated Splanchnic Vein Thrombosis

Splanchnic vein thrombosis (SVT), which includes portal, mesenteric, and splenic vein thrombosis and the Budd-Chiari syndrome, is an infrequent manifestation of venous thromboembolism (VTE). Like typical site VTE, SVT is also frequently associated with cancer, particularly intra-abdominal solid malignancies and myeloproliferative neoplasms (MPNs). The clinical presentation of SVT is nonspecific. Symptoms may be related to the underlying malignancy, and thrombosis is incidentally diagnosed by imaging studies for cancer staging or follow-up in a substantial proportion of cases. The occurrence of SVT predicts worse prognosis in patients with liver or pancreatic cancer and, not uncommonly, SVT may precede the diagnosis of cancer. Therefore, the occurrence of an apparently unprovoked SVT should prompt careful patient evaluation for the presence of an underlying malignancy or MPN. Cancer patients carry a high risk of VTE extension and recurrence and long-term anticoagulant treatment is suggested in the absence of high risk of bleeding. Either LMWH or direct oral anticoagulants (DOACs) are suggested for the treatment of patients with cancer-related SVT, although limited experience is available on the use of DOACs in these settings. Vitamin K antagonists (VKAs) are suggested for the short and long-term treatment of SVT associated with MPN. This review outlines the epidemiological aspects, pathogenesis, risk factors, and diagnosis of cancer-associated SVT, and addresses questions regarding the management of this challenging condition.

Budd-Chiari syndrome: consensus guidance of the Asian Pacific Association for the study of the liver (APASL)

Budd Chiari syndrome (BCS) is a diverse disease with regard to the site of obstruction, the predisposing thrombophilic disorders and clinical presentation across the Asia-Pacific region. The hepatic vein ostial stenosis and short segment thrombosis are common in some parts of Asia-Pacific region, while membranous obstruction of the vena cava is common in some and complete thrombosis of hepatic veins in others. Prevalence of myeloproliferative neoplasms and other thrombophilic disorders in BCS varies from region to region and with different sites of obstruction. This heterogeneity also raises several issues and dilemmas in evaluation and approach to management of a patient with BCS. The opportunity to recanalize hepatic vein in patients with hepatic vein ostial stenosis or inferior vena cava stenting or pasty among those membranous obstruction of the vena cava is a unique opportunity in the Asia-Pacific region to restore hepatic outflow closely mimicking physiology. In order to address these issues arising out of the diversity as well as the unique features in the region, the Asia Pacific Association for Study of Liver has formulated these guidelines for clinicians.

An Update on the Management of Budd-Chiari Syndrome

Budd-Chiari syndrome (BCS) is an uncommon condition, caused by obstruction to hepatic venous outflow. It is largely underdiagnosed, and a high index of suspicion is required for any patient with unexplained portal hypertension. The understanding of its etiology and pathology is improving with advances in diagnostic techniques. Recent studies reported an identifiable etiology in > 80% of cases. Myeloproliferative neoplasm (MPN) is the most common etiology, and genetic studies help in diagnosing latent MPN. Better cross-sectional imaging helps delineate the site of obstruction accurately. The majority of BCS patients are now treated by endovascular intervention and anticoagulation which have improved survival in this disease. Angioplasty of hepatic veins/inferior vena cava remains under-utilized at present. While surgical porto-systemic shunts are no longer done for BCS, liver transplantation is reserved for select indications. Some of the unresolved issues in the current management of BCS are also discussed in this review.

Molecular profiling and risk classification of patients with myeloproliferative neoplasms and splanchnic vein thromboses

Myeloproliferative neoplasms (MPNs) are the most frequent underlying causes of splanchnic vein thromboses (SVTs). MPN patients with SVTs (MPN-SVT) often have a unique presentation including younger age, female predominance, and low Janus kinase 2 (JAK2) mutation allele burden. This study aimed at identifying risk factors for adverse hematologic outcomes in MPN-SVT patients. We performed a retrospective study of a fully characterized cohort of MPN-SVT patients. The primary outcome was the incidence of evolution to myelofibrosis, acute leukemia, or death. Eighty patients were included in the testing cohort. Median follow-up was 11 years. Most of the patients were women with a mean age of 42 years and a diagnosis of polycythemia vera. The primary outcome was met in 13% of the patients and was associated with a JAK2V617F allele burden ≥50% (odds ratio [OR], 14.7) and presence of additional mutations in genes affecting chromatin/spliceosome (OR, 9). We identified high-risk patients (29% of the cohort) as those harboring at least 1 molecular risk factor: JAK2-mutant allele burden ≥50%, presence of chromatin/spliceosome/TP53 mutation. High-risk patients had worse event-free survival (81% vs 100%; P = .001) and overall survival at 10 years (89% vs 100%; P = .01) than low-risk patients. These results were confirmed in an independent validation cohort of 30 MPN-SVT patients. In conclusion, molecular profiling identified MPN-SVT patients with dismal outcome. In this high-risk population, a disease-modifying therapy should be taken into consideration to minimize the probability of transformation.

Treatment of portal vein thrombosis: an updated narrative review

Portal vein thrombosis (PVT) is the most frequent among the splanchnic vein thrombosis, accounting for 90% of cases. More than half of PVT are provoked by liver cirrhosis, solid cancer or myeloproliferative neoplasms. The remaining cases are non-malignant non-cirrhotic PVT and include either unprovoked events or thrombosis secondary to other less common risk factors (e.g. abdominal surgery, intrabdominal inflammations/infections, or hormonal stimuli). Anticoagulant therapy in patients with acute symptomatic PVT should be started early after diagnosis, if no active bleeding, to obtain greater vessel recanalization and reduce the occurrence of portal-hypertension related complications. Gastroesophageal varices do not represent a contraindication to anticoagulant treatment, as long as adequate measures have been undertaken for the prophylaxis of gastroesophageal bleeding. Different treatment options (unfractionated or low molecular weight heparin, vitamin K antagonists and direct oral anticoagulants [DOACs]) can be considered. In this narrative review we will discuss the treatment of PVT in the three most common scenarios (cirrhosis-associated, cancer-associated and non-malignant non-cirrhotic PVT). We will also discuss the role of the DOACs and summarise recent guidelines on this topic.

Pathogenesis of cardiovascular events in BCR-ABL1-negative myeloproliferative neoplasms

Thrombosis, both in arterial and venous territories, is the major complication of myeloproliferative neoplasms and is responsible for a high rate of morbidity and mortality. The currently accepted risk factors are an age over 60 years and a history of thrombosis. However, many complex mechanisms contribute to this increased prothrombotic risk, with involvement of all blood cell types, plasmatic factors, and endothelial cells. Besides, some cardiovascular events may originate from arterial vasospasm that could contribute to thrombotic complications. In this review, we discuss recent results obtained in mouse models in the light of data obtained from clinical studies. We emphasize on actors of thrombosis that are currently not targeted with current therapeutics but could be promising targets, i.e, neutrophil extracellular traps and vascular reactivity.

Is there a gender effect in polycythemia vera?

In recent times, there has been a growing interest in understanding the impact of gender on disease biology and clinical outcomes in Philadelphia-negative chronic myeloproliferative neoplasms. Among those, polycythemia vera (PV) is characterized by increased thrombotic risk, systemic symptoms, and overall reduced survival. Here, we aim to summarize data on whether and to what extent female sex can affect PV biology and outcome. To this end, we will discuss the latest acquisitions in terms of pathogenesis, diagnosis, epidemiology, clinical presentation and symptoms burden, thrombotic risk and related treatment strategies, and prognosis in female patients affected by PV.

Next-generation sequencing in the diagnosis of non-cirrhotic splanchnic vein thrombosis

BACKGROUND & AIMS

Myeloproliferative neoplasms (MPNs) are the most frequent cause of non-tumoural non-cirrhotic splanchnic vein thrombosis (NC-SVT). Diagnosis of MPN is based on blood cell count alterations, bone marrow histology, and detection of specific gene mutations. Next-generation sequencing (NGS) allows the simultaneous evaluation of multiple genes implicated in myeloid clonal pathology. The aim of this study was to evaluate the potential role of NGS in elucidating the aetiology of NC-SVT.

METHODS

DNA samples from 80 patients (75 with idiopathic or exclusively local factor [Idiop/loc-NC-SVT] and 5 with MPN and NC-SVT [SVT-MPN] negative for Janus kinase 2 gene [JAK2] [V617F and exon 12], calreticulin gene [CALR], and thrombopoietin gene [MPL] mutations by classic techniques) were analysed by NGS. Mutations involved in myeloid disorders different from JAK2, CALR, and MPL genes were categorised as high-molecular-risk (HMR) variants or variants of unknown significance.

RESULTS

In 2/5 triple-negative SVT-MPN cases (40%), a mutation in exon 12 of JAK2 was identified. JAK2-exon 12 mutation was also identified in 1/75 patients with Idiop/loc-NC-SVT. Moreover, 28/74 (37.8%) of the remaining Idiop/loc-NC-SVT had at least 1 HMR variant. Sixty-two patients with Idiop/loc-NC-SVT were not receiving long-term anticoagulation and 5 of them (8.1%) had recurrent NC-SVT. This cumulative incidence was significantly higher in patients with HMR variants than in those without.

CONCLUSIONS

NGS identified JAK2-exon12 mutations not previously detected by conventional techniques. In addition, NGS detected HMR variants in approximately one-third of patients with Idiop/loc-NC-SVT. These patients seem to have a higher risk of splanchnic rethrombosis. NGS might be a useful diagnostic tool in NC-SVT.

LAY SUMMARY

Next-generation sequencing (NGS) performs massive sequencing of DNA allowing the simultaneous evaluation of multiple genes even at very low mutational levels. Application of this technique in a cohort of patients with non-cirrhotic non-tumoral portal vein thrombosis (NC-SVT) and a negative study for thrombophilic disorders was able to identify patients with a mutation in exon 12 not previously detected by conventional techniques. Moreover, NGS detected High Molecular Risk (HMR)-variants (Mutations involved in myeloid disorders different from JAK2, CALR and MPL genes) in approximately one third of patients. These patients appear to be at increased risk of rethrombosis. All these findings supports NGS as a potential useful tool in the management of NC-SVT.

Venous thrombosis of the liver: current and emerging concepts in management

Venous thrombosis within the hepatic vasculature is associated with a distinct array of risk factors, characteristics, and potential complication. As such, it entails unique management considerations and strategies relative to the more common categories of venous thromboembolic disease. Although broadly divided into thrombosis of the afferent vasculature (the portal venous system) and efferent vasculature (the hepatic venous system), presentations and management strategies within these groupings are heterogeneous. Management decisions are influenced by a variety of factors including the chronicity, extent, and etiology of thrombosis. In this review we examine both portal vein thrombosis and hepatic vein thrombosis (and the associated Budd-Chiari Syndrome). We consider those factors which most impact presentation and most influence treatment. In so doing, we see how the particulars of specific cases introduce nuance into clinical decisions. At the same time we attempt to organize our understanding of such cases to help facilitate a more systematic approach. Critically, we must recognize that although increasing evidence is emerging to help guide our management strategies, the available data remain limited and largely retrospective. Indeed, current paradigms are based largely on observational experiences and expert consensus. As new and more rigorous studies emerge, treatment strategies are likely to be continually refined, and paradigm shifts are sure to occur.

Budd-Chiari Syndrome: An Uncommon Cause of Chronic Liver Disease that Cannot Be Missed

Budd-Chiari syndrome (BCS), or hepatic venous outflow obstruction, is a rare cause of liver disease that should not be missed. Variable clinical presentation among patients with BCS necessitates a high index of suspicion to avoid missing this life-threatening diagnosis. BCS is characterized as primary or secondary, depending on etiology of venous obstruction. Most patients with primary BCS have several contributing risk factors leading to a prothrombotic state. A multidisciplinary stepwise approach is integral in treating BCS. Lifelong anticoagulation is recommended. Long-term monitoring of patients for development of cirrhosis, complications of portal hypertension, hepatocellular carcinoma, and progression of underlying diseases is important.

Cellular and Molecular Aspects of Blood Cell-Endothelium Interactions in Vascular Disorders

In physiology and pathophysiology the molecules involved in blood cell–blood cell and blood cell–endothelium interactions have been identified. Platelet aggregation and adhesion to the walls belonging to vessels involve glycoproteins (GP), GP llb and GP llla and the GP Ib–IX–V complex. Red blood cells (RBCs) in normal situations have little interaction with the endothelium. Abnormal adhesion of RBCs was first observed in sickle cell anemia involving vascular cell adhesion molecule (VCAM)-1, α4β1, Lu/BCAM, and intercellular adhesion molecule (ICAM)-4. More recently RBC adhesion was found to be increased in retinal-vein occlusion (RVO) and in polycythemia vera (PV). The molecules which participate in this process are phosphatidylserine and annexin V in RVO, and phosphorylated Lu/BCAM and α5 laminin chain in PV. The additional adhesion in diabetes mellitus occurs due to the glycated RBC band 3 and the advanced glycation end-product receptors. The multiligand receptor binds advanced glycation end products (AGEs) or S100 calgranulins, or β-amyloid peptide. This receptor for advanced glycation end products is known as RAGE. The binding to RAGE-activated endothelial cells leads to an inflammatory reaction and a prothrombotic state via NADPH activation and altered gene expression. RAGE blockade is a potential target for drugs preventing the deleterious consequences of RAGE activation.

Optimized and Personalized Phlebotomy Schedules for Patients Suffering From Polycythemia Vera

Polycythemia vera (PV) is a slow-growing type of blood cancer, where the production of red blood cells (RBCs) increase considerably. The principal treatment for targeting the symptoms of PV is bloodletting (phlebotomy) at regular intervals based on data derived from blood counts and physician assessments based on experience. Model-based decision support can help to identify optimal and individualized phlebotomy schedules to improve the treatment success and reduce the number of phlebotomies and thus negative side effects of the therapy. We present an extension of a simple compartment model of the production of RBCs in adults to capture patients suffering from PV. We analyze the model's properties to show the plausibility of its assumptions. We complement this with numerical results using exemplary PV patient data. The model is then used to simulate the dynamics of the disease and to compute optimal treatment plans. We discuss heuristics and solution approaches for different settings, which include constraints arising in real-world applications, where the scheduling of phlebotomies depends on appointments between patients and treating physicians. We expect that this research can support personalized clinical decisions in cases of PV.

Congenital antithrombin deficiency in patients with splanchnic vein thrombosis

BACKGROUND AND AIMS

Splanchnic vein thromboses (SVT) are a rare condition that can be life-threatening. The most severe thrombophilia associated to SVT is antithrombin (AT) deficiency, usually caused by SERPINC1 mutations. Although transitory AT deficiencies and congenital disorders of the N-glycosylation pathways (CDG) have been recently reported as causes of AT deficiency, the current AT clinical screening still only includes anti-FXa activity. This study aims to (a) improve the detection of AT deficiency in SVT and (b) characterize the features of AT deficiency associated with SVT.

METHODS

The study was performed in 2 cohorts: (a) 89 SVT patients with different underlying etiologies but in whom AT deficiency had been ruled out by classical diagnostic methods; and (b) 271 unrelated patients with confirmed AT deficiency and venous thrombosis. AT was evaluated by functional (anti-FXa and anti-FIIa) and immunological methods (ELISA, crossed immunoelectrophoresis, western blot), and SERPINC1 sequencing was performed.

RESULTS

In 4/89 patients (4.5%) additional alterations in AT were found (two had SERPINC1 mutations, one had a specific variant causing transient AT deficiency and one patient had CDG). In 11 of the 271 patients (4.1%) with AT deficiency and thrombosis, thrombosis was located at the splanchnic venous territory.

CONCLUSIONS

Antithrombin deficiency may be underdiagnosed by current clinical screening techniques. Therefore, a comprehensive AT evaluation should be considered in cases of rethrombosis or doubtful interpretation of anti-FXa activity levels. SVT is a relatively common localization of the thrombotic event in patients with congenital AT deficiency.

Venous Thrombosis and Hypercoagulability in the Abdomen and Pelvis: Causes and Imaging Findings

Venous thromboembolism (VTE), which includes deep venous thrombosis and pulmonary embolism, is a significant cause of morbidity and mortality. In recent decades, US, CT, and MRI have surpassed catheter-based angiography as the imaging examinations of choice for evaluation of vascular structures and identification of thrombus owing to their ready availability, noninvasive nature, and, in the cases of US and MRI, lack of exposure to ionizing radiation. As a result, VTE and associated complications are commonly identified in day-to-day radiologic practice across a variety of clinical settings. A wide range of hereditary and acquired conditions can increase the risk for development of venous thrombosis, and many patients with these conditions may undergo imaging for unrelated reasons, leading to the incidental detection of VTE or one of the associated complications. Although the development of VTE may be an isolated occurrence, the imaging findings, in conjunction with the clinical history and vascular risk factors, may indicate a predisposing condition or underlying diagnosis. Furthermore, awareness of the many clinical conditions that result in an increased risk of venous thrombosis may aid in detection of thrombus and any concomitant complications. For these reasons, it is important that practicing radiologists be familiar with the multimodality imaging findings of thrombosis, understand the spectrum of diseases that contribute to the development of thrombosis, and recognize the potential complications of hypercoagulable states and venous thrombosis. Online DICOM image stacks and supplemental material are available for this article. ^©RSNA, 2020.

Review of Budd-Chiari Syndrome

This study aims to report the Budd-Chiari syndrome clinical research status and progress that has occurred in over nearly 30 years in China, and emphasize the value of imaging in facilitating the diagnosis of Budd-Chiari syndrome based on more than 2500 cases. Findings on ultrasonography, computed tomography, magnetic resonance imaging, and digital subtraction angiography images are used to propose new Budd-Chiari syndrome types and subtypes. The new subtype classification presented here has important value for guiding interventional treatment. This study also proposes a new concept of anatomical and functional obstruction of hepatic vein that stresses the compensatory value of accessory hepatic vein and azygos vein and describes the risk of manipulation of the communication branch of inferior vena cava obstruction in interventional therapy.

Whole-Exome Sequencing in 22 Young Ischemic Stroke Patients With Familial Clustering of Stroke

Backgrounds and Purpose- Although new methods for genetic analyses are rapidly evolving, there are currently knowledge gaps in how to detect Mendelian forms of stroke. Methods- We performed whole-exome sequencing in 22 probands, under 56 years at their first ischemic stroke episode, from multi-incident stroke families. With the use of a comprehensive stroke-gene panel, we searched for variants in stroke-related genes. The probands' clinical stroke subtype was related to clinical characteristics previously associated with pathogenic variants in these genes. Relatives were genotyped in 7 families to evaluate stroke-gene variants of unknown significance. In 2 larger families with embolic stroke of unknown source, whole-exome sequencing was performed in additional members to examine the possibility of identifying new stroke genes. Results- Six of 22 probands carried pathogenic or possibly pathogenic variants in genes reported to be associated with their stroke subtype. A known pathogenic variant in NOTCH3 and a possibly pathogenic variant in ACAD9 gene were identified. A novel JAK2:c.3188G>A (p.Arg1063His) mutation was seen in a proband with embolic stroke of undetermined source and prothrombotic status. However, penetrance in the family was incomplete. COL4A2:c.3368A>G (p.Glu1123Gly) was detected in 2 probands but did not cosegregate with the disease in their families. Whole-exome sequencing in multiple members of 2 pedigrees with embolic stroke of undetermined source revealed possibly pathogenic variants in genes not previously associated with stroke, GPR142:c.148C>G (p.Leu50Val), and PTPRN2:c.2416A>G (p.Ile806Val); LRRC1 c.808A>G (p.Ile270Val), SLC7A10c.1294dupG (p.Val432fs), IKBKB: c.1070C>T (p.Ala357Val), and OXGR1 c.392G>A (p.Arg131His), respectively. Conclusions- Screening with whole-exome sequencing using a comprehensive stroke-gene panel may identify rare monogenic forms of stroke, but careful evaluation of clinical characteristics and potential pathogenicity of novel variants remain important. In our study, the majority of individuals with familial aggregation of stroke lacked any identified genetic causes.

Cerebral and Splanchnic Vein Thrombosis: Advances, Challenges, and Unanswered Questions

Cerebral vein thrombosis (CVT) and splanchnic vein thrombosis (SVT) are two manifestations of venous thromboembolism (VTE) at unusual sites. They have an incidence at least 25-50 times lower than usual site VTE, but represent true clinical challenges. Recent evidence on the epidemiology, risk factors, prognosis, and treatment of CVT and SVT has been published in the last two decades, thus contributing to a better understanding of these diseases. The improvement in imaging techniques and a higher degree of clinical suspicion may have led to the observed increased frequency, whereas a better knowledge of provoking mechanisms could have contributed to reducing the proportion of events classified as unprovoked or idiopathic (13%-21% of CVT, 15%-27% of SVT). Few small randomized clinical trials and a number of observational studies, although hampered by heterogeneous therapeutic approaches, shed light on the safety and effectiveness of anticoagulant therapy in these populations. However, there are still some grey areas that warrant future research. In this narrative review, we discuss recent advances and therapeutic challenges in CVT and SVT.

Natural history of polycythemia vera and essential thrombocythemia presenting with splanchnic vein thrombosis

Patients with polycythemia vera (PV) or essential thrombocythemia (ET) presenting with splanchnic vein thrombosis (SVT) might have a specific clinico-biological profile. To investigate this hypothesis, 3705 PV/ET patients from three national registers, 118 of them presenting with SVT, were reviewed. After correction for age and sex, PV/ET patients with SVT showed an increased risk of death (HR 2.47, 95% CI 1.5-4.01, p < 0.001), venous thrombosis (IRR 3.4, 95%CI 2.1-5.5, p < 0.001), major bleeding (IRR 3.6, 95%CI 2.3-5.5, p < 0.001), and second cancer (IRR 2.37, 95%CI 1.4-4.1, p = 0.002). No case of acute leukemia was documented among patients with PV/ET presenting with SVT and seven of them (6%) progressed to myelofibrosis. SVT was not associated with lower risk of MF after correction by age and sex. Patients with SVT more frequently died from complications related to hepatic disease, major bleeding, or second cancer, resulting in a 5-year reduction of age- and sex-adjusted median survival. In conclusion, PV and ET patients presenting with SVT have shorter survival than patients with PV and ET of the same age and sex. This excess mortality is related to liver disease, major bleeding, and second cancer rather than to the natural evolution of the MPN.

Escalating interventional recanalization therapy in non-cirrhotic, non-malignant acute portal vein thrombosis

OBJECTIVE

To evaluate the effectiveness of interventional therapy in acute, non-malignant, non-cirrhotic portal vein thrombosis.

METHODS

We present a retrospective study of eight consecutive patients who presented with an acute non-malignant, non-cirrhotic portal vein thrombosis and were treated by mechanical recanalization using an escalating scheme including local aspiration, thrombolysis, rheolysis and the implantation of transjugular intrahepatic portosystemic shunt or other visceral stents.

RESULTS

Recanalization rates applying the escalating scheme were good, with a success rate of 75%. However, major complications occurred in 50% of patients, mostly due to bleeding at the percutaneous access site, and minor complications in 12.5% of patients.

CONCLUSION

Interventional therapy is effective in acute portal vein thrombosis, but should only be performed at specialized centers and based on an individual treatment decision.

Current knowledge in pathophysiology and management of Budd-Chiari syndrome and non-cirrhotic non-tumoral splanchnic vein thrombosis

Budd-Chiari syndrome and non-cirrhotic non-tumoral portal vein thrombosis are 2 rare disorders, with several similarities that are categorized under the term splanchnic vein thrombosis. Both disorders are frequently associated with an underlying prothrombotic disorder. They can cause severe portal hypertension and usually affect young patients, negatively influencing life expectancy when the diagnosis and treatment are not performed at an early stage. Yet, they have specific features that require individual consideration. The current review will focus on the available knowledge on pathophysiology, diagnosis and management of both entities.

Update on Management of Portal Vein Thrombosis and the Role of Novel Anticoagulants

The clinical management of portal vein thrombosis (PVT) remains ambiguous due to its heterogeneous presentations and its associations with liver disease, malignancy, and hypercoagulable states. The natural history and clinical outcome of PVT are highly variable, dependent upon size, extent and degree of the thrombotic occlusion, as well as the physiological impact of patient comorbidities. While existing clinical guidelines consistently recommend low molecular weight heparin or vitamin K antagonist anticoagulation in cirrhotic patients with symptomatic acute PVT, management of asymptomatic and chronic PVT may need to be determined on a case-by-case basis, factoring in the state of underlying liver disease. In general, patients with PVT and underlying malignancy should be anticoagulated to alleviate symptoms and prevent recurrences that could disrupt the cancer management. However, existing clinical data does not support routine anticoagulation of cirrhotic patients with asymptomatic PVT in the absence of underlying cancer. While low molecular weight heparin and vitamin K antagonist remain the most commonly used agents in PVT, an emerging body of clinical evidence now suggests that direct-acting oral anticoagulants may be used safely and effectively in PVT. As such, direct-acting oral anticoagulants may offer a more convenient anticoagulation alternative for PVT management in future practice.

Diagnosis, Development, and Treatment of Portal Vein Thrombosis in Patients With and Without Cirrhosis

Portal vein thrombosis unrelated to solid malignancy is common in patients with cirrhosis, but less frequently observed in patients without cirrhosis. Prompt diagnosis and management of acute symptomatic portal vein thrombosis are essential. Failure to detect and treat thromboses can result in mesenteric ischemia, chronic cavernous transformation, and complications of portal hypertension. In patients with cirrhosis, development of portal vein thrombosis is often insidious and remains undetected until its incidental detection. Management of portal vein thrombosis in patients with cirrhosis is more controversial. However, there are data to support treatment of specific patients with anticoagulation agents. We review the common and distinct features of portal vein thromboses in patients without liver tumors, with and without cirrhosis.

Thromboembolic events in polycythemia vera

Thromboembolic events and cardiovascular disease are the most prevalent complications in patients with polycythemia vera (PV) compared with other myeloproliferative disorders and are the major cause of morbidity and mortality in this population. Moreover, a vascular complication such as arterial or venous thrombosis often leads to the diagnosis of PV. The highest rates of thrombosis typically occur shortly before or at diagnosis and decrease over time, probably due to the effects of treatment. Important risk factors include age (≥ 60 years old) and a history of thrombosis; elevated hematocrit and leukocytosis are also associated with an increased risk of thrombosis. The goal of therapy is to reduce the risk of thrombosis by controlling hematocrit to < 45%, a target associated with reduced rates of cardiovascular death and major thrombosis. Low-risk patients (< 60 years old with no history of thrombosis) are managed with phlebotomy and low-dose aspirin, whereas high-risk patients (≥ 60 years old and/or with a history of thrombosis) should be treated with cytoreductive agents. Interferon and ruxolitinib are considered second-line therapies for patients who are intolerant of or have an inadequate response to hydroxyurea, which is typically used as first-line therapy. In this review, we discuss factors associated with thrombosis and recent data on current treatments, including anticoagulation, highlighting the need for more controlled studies to determine the most effective cytoreductive therapies for reducing the risk of thrombosis in patients with PV.

Splanchnic venous thrombosis in JAK2 V617F mutation positive myeloproliferative neoplasms - long term follow-up of a regional case series

Background

Splanchnic Vein Thrombosis (SVT) is strongly associated with underlying JAK2 V617F positive myeloproliferative neoplasms (MPN).

Methods

Patients attending the tertiary haematology service in Northern Ireland with SVT and underlying JAK2 V617F MPN were identified by consultant staff. A retrospective audit was undertaken to examine therapeutic interventions and relevant outcomes. Descriptive statistics were used for qualitative data whilst students t-test allowed comparison of quantitative data.

Results

We report on the medium to long term follow-up of fourteen patients presenting with SVT on the basis of JAK2 V617F positive MPN. Females comprised 78.5% of the patients and there was an average age of 47.3 years at time of diagnosis. There was significant morbidity evident at diagnosis with liver transplantation attempted in all patients with Budd Chiari (n = 3), oesophageal varices present in 57.1%, ascites present in 42.8% and splenomegaly evident in 71.4%. 42.8% of patients did not exhibit classical phenotypic blood count findings for MPN at time of diagnosis. Over a median follow-up of 88.5 months (range = 8-211 months) recurrence of SVT was only documented in the setting of interventional liver procedure. Major haemorrhagic complications were recorded in 35.7% of patients and there was an association with dual anticoagulation and antiplatelet use. Recurrent thrombosis outside of the splanchnic venous system occurred in 28.5% of patients, predominantly occurring off therapeutic anticoagulation. No deaths were recorded and one transformation to myelofibrosis was seen during follow-up. Cytoreduction therapies were routinely used but had a high discontinuation rate due to cytopenias and intolerance.

Conclusion

This analysis highlights the complexities of management of this group of patients over a period of long follow-up with a focus on the evidence behind therapeutic options.