From Budd-Chiari syndrome to acquired von Willebrand syndrome: thrombosis and bleeding complications in the myeloproliferative neoplasms

Correlation between IPSET-t risk at diagnosis and subsequent hemorrhage in patients with essential thrombocythemia; a single institution experience

Essential thrombocythemia (ET) is a myeloproliferative neoplasm characterized by an increased risk of thrombotic and hemorrhagic events, that represent the leading causes of mortality and morbidity. Currently, while thrombotic risk is assessed through the IPSET-t and r-IPSET scores, there is no specific prognostic tool used to predict hemorrhagic risk in ET. The aim of the study was to define incidence and risk factors connected to hemorrhagic events by retrospectively analyzing 308 ET patients diagnosed between 1996 and 2022 at the Division of Hematology of Udine and treated according to the current international guidelines. According to molecular status, 193 patients (62.7%) were JAK2 mutated, 66 (21.4%) had a CALR mutation, 14 (4.5%) had a MPL mutation, 21 patients (6.8%) were "triple negative," and 14 patients (4.5%) were not evaluable. According to IPSET-t score, 49.7% patients were at high, 24.3% at intermediate, and 26.0% at low-risk, respectively. Twelve (3.9%) patients experienced bleeding at ET diagnosis, while 24 (7.8%) had at least one hemorrhagic event during follow-up at a median time of 103 months (range: 1-309). Forty hemorrhagic events were totally recorded and defined as minor in 22 cases, moderate in 11 cases, and severe in 7 cases. Cumulative incidence (CI) of hemorrhage at 10 and 20 years was 6.0% and 12.0%, respectively. A statistically significant correlation between hemorrhagic risk and IPSET-t score emerged: 10 years hemorrhage CI was 3.2% for low-risk, 2.9% for intermediate-risk, and 9.8% for high-risk patients, respectively (p=0.002). We found no correlation between hemorrhagic risk and gender or mutational status. Results of our study highlight the validity of IPSET-t score in predicting individual hemorrhagic risk among ET patients, suggesting a possible role of IPSET-t scoring system as a global evaluator for vascular events in ET patients.

Abdominal aortic calcification in patients newly diagnosed with essential thrombocythemia

Background

Although atherosclerosis is likely to be involved in the development of arterial thrombotic events in patients with essential thrombocythemia (ET), abdominal aortic calcification (AAC) has rarely been investigated. We evaluated the prevalence and clinical relevance of AAC at the time of ET diagnosis.

Methods

This retrospective study included patients newly diagnosed with ET who underwent abdominal computed tomography (CT) at the time of diagnosis between January 2002 and December 2021 at Chungnam National University Hospital, Daejeon, Korea. CT images were reviewed and an aortic calcification score was assigned.

Results

Of the 94 patients (median age, 62 yr; range, 18‒90 yr), AAC was detected in 62 (66.0%). AAC was most commonly mild (33.0%), followed by moderate (22.7%) and severe (5.3%). Old age [odds ratio (OR), 34.37; 95% confidence interval (CI), 12.32‒95.91; P＜0.001] was an independent risk factor for AAC. The patients with AAC had a higher WBC count (11.8±4.7 vs. 9.7±2.9×109/L, P=0.017), higher neutrophil-to-lymphocyte ratio (4.3±2.7 vs. 3.1±1.5, P=0.039), and higher JAK2V617F positivity (81.5% vs. 58.8%, P=0.020) compared to those without AAC. AAC was an independent risk factor for arterial thrombotic vascular events that occurred before or at diagnosis of ET (OR, 4.12; 95% CI, 1.11‒15.85; P=0.034).

Conclusion

AAC is common in patients with ET and is associated with arterial thrombotic events.

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.

Splenic Infarction in Patients with Philadelphia-negative Myeloproliferative Neoplasms

Objective We retrospectively analyzed the prevalence and clinical features of splenic infarctions in patients with Philadelphia chromosome-negative myeloproliferative neoplasms (Ph^- MPNs). Patients Patients diagnosed with essential thrombocythemia (ET), polycythemia vera (PV), prefibrotic/early primary myelofibrosis (pre-PMF), or PMF from January 1996 to October 2020 in Chungnam National University Hospital, Daejeon, Korea, were reviewed. Results A total of 347 patients (143 ET, 129 PV, 44 pre-PMF, and 31 PMF patients; 201 men and 146 women) with a median age of 64 (range 15-91) years old were followed up for a median of 4.7 (range 0.1-26.5) years. Fifteen (4.3%) patients exhibited splenic infarctions at the diagnosis. These were most common in PMF patients (12.9%), followed by pre-PMF (9.1%) and PV (5.4%) patients. Multifocal infarcts (60.0%) were most common, followed by solitary (33.3%) and extensive infarcts (6.7%). The cumulative incidence of thrombosis in patients with splenic infarctions tended to be higher than in those lacking infarctions (10-year incidence 46.7% vs. 21.0% in PV; p=0.215; 33.3% vs. 17.9% in pre-PMF; p=0.473) patients, but statistical significance was lacking. Palpable splenomegaly (hazard ratio 14.89; 95% confidence interval 4.00-55.35; p<0.001) was the only independent risk factor for splenic infarction. During follow-up, 5 (1.4%) patients developed splenic infarctions. Conservative treatment adequately controlled the symptoms; no serious complications were noted in any patient. Conclusion Splenic infarctions occurred most frequently in patients with PMF; it was rare in patients with ET. The clinical courses were generally mild.

Hemorrhages in polycythemia vera and essential thrombocythemia: epidemiology, description, and risk factors, learnings from a large cohort

BACKGROUND

The management of myeloproliferative neoplasms (MPN) is based on the reduction of thrombosis risk. The incidence, impact, and risk factors of bleedings have been less studied.

METHOD

All patients with polycythemia vera (n=339) or essential thrombocythemia (n=528) treated in our center are included in OBENE cohort (NCT02897297). Major bleeding (MB) and clinically relevant non-major bleeding (CRNMB) occurring after diagnosis were included, except after leukemic transformation.

RESULTS

With a median follow-up of 8.3 years, incidence of hemorrhages was 1.85% patient/year, with an incidence of MB of 0.95% patient/year. The 10-year bleeding-free survival was 89%. The most frequent locations were digestive tractus, "mouth, nose and throat" and muscular hematoma. The case fatality rate of MB was 25%. The proportion of potentially avoidable iatrogenic bleeding was remarkable (17.6%). In multivariable analysis, eight risk factors of bleeding were identified: leukocytes >20 giga/l at diagnosis (HR=5.13 95%CI [1.77;14.86]), secondary hemopathies (HR=2.99 95%CI [1.27;7.04]), aspirin use at diagnosis (HR=2.11 95%CI [1.24;3.6]), platelet count >1000 giga/l at diagnosis (HR=1.93, 95%CI [1.11;3.36]), history of hemorrhage (HR=1.82 95%CI [1.03;3.24]), secondary cancers (HR=1.71 95%CI [1.01;2.89]), atrial fibrillation (HR=1.66, 95%CI [1.01;2.72]) and male gender (HR=1.54, 95%CI [1.02-2.33]). The majority of patients taking hydroxyurea displayed a non-macrocytic median corpuscular value in the months preceding bleeding (51.4%).

DISCUSSION

The morbidity and mortality of bleedings in MPN should not be underestimated, and some patients could beneficiate from cytoreduction in order to reducing bleeding risk. Iatrogenic bleedings represent a substantial proportion of bleeding and could be better prevented.

HemosIL VWF:GPIbR assay has a greater sensitivity than VWF:RCo technique to detect acquired von Willebrand syndrome in myeloproliferative neoplasms

BACKGROUND

Acquired von Willebrand syndrome (AVWS) is frequent in patients with myeloproliferative neoplasms (MPNs). For VWF functional evaluation, ristocetin cofactor activity by aggregometry (VWF: RCo) is considered the gold standard but have limitations, and automated activities measurement has been developed such as the HemosIl VWF:RCo Werfen® with particle agglutination (VWF:GPIbR).

OBJECTIVES

To evaluate the performance of VWF:GPIbR with HemosIL VWF:RCo Werfen® (VWF:GPIbR) versus VWF:RCo in patients with thrombocytosis in the context of MPNs (T-MPNs) and in patients with secondary thrombocytosis (ST).

PATIENTS/METHODS

MPNs patients with thrombocytosis >450 G/L (T-MPNs) were compared to patients with secondary thrombocytosis (ST) due to inflammation or iron deficiency. VWF activity (VWF:Act) was analyzed using VWF:RCo or VWF:GPIbR. VWF analysis was completed by analysis of VWF multimers and VWF collagen binding (CB) assay (VWF:CB).

RESULTS

33 T-MPNs and 18 ST patients were included. Compared to aggregometry, evaluation of VWF:Act by VWF:GPIbR leaded to lower values in T-MPNs patients, but also in ST patients. Interestingly, whereas VWF:RCo/VWF:Ag ratio did not reveal differences between T-MPNs and ST patients, VWF:GPIbR/VWF:Ag ratio analysis allowed to suspect AVWS only in T-MPNs patients. Using the distribution of VWF multimers analysis and VWF:CB, we here demonstrated that VWF:GPIbR allows AVWS diagnosis in 9 T-MPNs as opposed to aggregometry.

CONCLUSIONS

Evaluation of VWF:Act using VWF:GPIbR has a greater sensitivity compared to aggregometry to detect AVWS in T-MPNs patients.

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.

Circulating Protein Disulfide Isomerase Is Associated with Increased Risk of Thrombosis in JAK2-Mutated Myeloproliferative Neoplasms

PURPOSE

Thromboembolic events (TE) are the most common complications of myeloproliferative neoplasms (MPN). Clinical parameters, including patient age and mutation status, are used to risk-stratify patients with MPN, but a true biomarker of TE risk is lacking. Protein disulfide isomerase (PDI), an endoplasmic reticulum protein vital for protein folding, also possesses essential extracellular functions, including regulation of thrombus formation. Pharmacologic PDI inhibition prevents thrombus formation, but whether pathologic increases in PDI increase TE risk remains unknown.

EXPERIMENTAL DESIGN

We evaluated the association of plasma PDI levels and risk of TE in a cohort of patients with MPN with established diagnosis of polycythemia vera (PV) or essential thrombocythemia (ET), compared with healthy controls. Plasma PDI was measured at enrollment and subjects followed prospectively for development of TE.

RESULTS

A subset of patients, primarily those with JAK2-mutated MPN, had significantly elevated plasma PDI levels as compared with controls. Plasma PDI was functionally active. There was no association between PDI levels and clinical parameters typically used to risk-stratify patients with MPN. The risk of TE was 8-fold greater in those with PDI levels above 2.5 ng/mL. Circulating endothelial cells from JAK2-mutated MPN patients, but not platelets, demonstrated augmented PDI release, suggesting endothelial activation as a source of increased plasma PDI in MPN.

CONCLUSIONS

The observed association between plasma PDI levels and increased risk of TE in patients with JAK2-mutated MPN has both prognostic and therapeutic implications.

New Developments in Diagnosis and Management of Acquired Hemophilia and Acquired von Willebrand Syndrome

Acquired hemophilia A and acquired von Willebrand syndrome are rare, but life-threatening bleeding disorders that require prompt diagnosis and treatment by hematologists. Acquired hemophilia A is defined as an acquired severe bleeding tendency caused by autoantibody formation against coagulation factor VIII. Acquired von Willebrand syndrome is characterized by a new onset bleeding tendency caused by a reduced concentration and/or function of von Willebrand factor. These disorders are associated with a variety of underlying disorders, including various hematological malignancies, for example, plasma cell disorders, lymphoproliferative disorders, monoclonal gammopathy of undetermined significance, and myeloproliferative neoplasms. It is of utmost important to recognize these acquired bleeding disorders in these patients who are at risk for severe bleeding, and to perform additional diagnostic hemostasis laboratory evaluation. This will enable immediate diagnosis of the acquired bleeding disorder and management of both the bleeding episodes and the causative underlying disorder. In recent years, several new etiological factors for acquired hemophilia A, such as treatment with immune checkpoint inhibitors or DPP-4 inhibitors and SARS-CoV2 infection, and for acquired von Willebrand syndrome, for example, left ventricular assist devices, have been identified and also new treatment options have become available. In this concise review, the most recent data on etiology, diagnosis, and treatment of acquired bleeding disorders are presented and discussed.

Clinical, laboratory, and genetic risk factors for thrombosis in sickle cell disease

Sickle cell disease (SCD) patients are at a four- to 100-fold increased risk for thrombosis compared with the general population, although the mechanisms and risk factors are not clear. We investigated the incidence and predictors for thrombosis in a retrospective, longitudinal cohort of 1193 pediatric and adult SCD patients treated at our institution between January 2008 and December 2017. SCD diagnosis and thrombotic complications were identified using International Classification of Diseases coding and verified through medical chart review. Clinical and laboratory data were extracted from the medical records. With a median follow-up of 6.4 years, 208 (17.4%) SCD patients experienced 352 thrombotic events (64 strokes, 288 venous thromboembolisms [VTE]). Risk factors for stroke included older age and HbSS/Sβ0-genotype and a lower hemoglobin (Hb) F% in the subset of HbSS/Sβ0-genotype patients (P < .05). VTE risk was independently associated with lower estimated glomerular filtration rate, hydroxyurea (HU) use, HbSS/Sβ0 genotype, and higher white blood cell (WBC) counts and Hb (P ≤ .03). Two thrombomodulin gene variants previously associated with thrombosis in the general African American population, THBD rs2567617 (minor allele frequency [MAF] 0.25; odds ratio [OR], 1.5; P = .049) and THBD rs1998081 (MAF, 0.24; OR, 1.5; P = .059), were associated with thrombosis in this cohort. In summary, thrombotic complications are common, and several traditional and SCD-specific risk factors are associated with thrombotic risk. Future studies integrating clinical, laboratory, and genetic risk factors may improve our understanding of thrombosis and guide intervention practices in SCD.

A systematic review of antithrombotic treatment of venous thromboembolism in patients with myeloproliferative neoplasms

Patients with myeloproliferative neoplasms (MPNs), polycythemia vera, essential thrombocythemia, and primary myelofibrosis, have an increased risk of thrombosis. Risk of recurrent thrombosis can be reduced with antithrombotic therapy and/or cytoreduction, but the optimal long-term management in patients with MPN with a history of venous thromboembolism (VTE) is unknown, and clinical practice is heterogeneous. We performed a systematic review and meta-analysis of randomized trials and observational studies evaluating anticoagulant and/or antiplatelet therapy, with or without cytoreduction, in MPN patients with a history of VTE. A total of 5675 unique citations were screened for eligibility. No randomized trials were identified. Ten observational studies involving 1295 patients with MPN were included in the analysis. Overall, 23% had an arterial or recurrent venous thrombotic event on follow-up. The recurrence risk was lowest for patients on oral anticoagulation plus cytoreduction (16%); 55 of 313 (18%) with vitamin K antagonists (VKA) and 5 of 63 (8%) with direct oral anticoagulants (DOACs). In 746 analyzed patients, the risk of recurrent VTE ranged up to 33% (median 13%) and was low in 63 DOAC plus cytoreduction-treated patients (3.2%). All types of antithrombotic treatments were associated with a lower risk of recurrent VTE when combined with cytoreduction. Most studies had a high risk of bias, whereas clinical and statistical heterogeneity led to inconsistent and imprecise findings. In summary, evidence on the optimal antithrombotic treatment of VTE in patients with MPN is based on observational studies only with low certainty for all strategies. Our data suggest that a combination of anticoagulation and cytoreduction may provide the lowest recurrence risk.

Novel Pathophysiological Mechanisms of Thrombosis in Myeloproliferative Neoplasms

PURPOSE OF REVIEW

Thrombosis remains a leading cause of morbidity and mortality in BCR/ABL negative myeloproliferative neoplasms (MPN). Circulating blood cells are both increased in quantity and qualitatively abnormal in MPN, resulting in an increased thrombotic risk. Herein, we review recently elucidated mechanisms of MPN thrombosis and discuss implications of drugs currently under investigation for MPN.

RECENT FINDINGS

Recent studies highlight that in JAK2^V617F granulocytes and platelets, thrombo-inflammatory genes are upregulated. Furthermore, in JAK2^V617F granulocytes, protein expression of integrin CD11b, tissue factor, and leukocyte alkaline phosphatase are all increased. Overall, myeloid cells, namely neutrophils, may contribute in several ways, such as through increased adhesion via β1 integrin binding to VCAM1, increased infiltration, and enhanced inducibility to extrude neutrophil extracellular traps. Non-myeloid inflammatory cells may also contribute via secretion of cytokines. With regard to red blood cells, number, rigidity, adhesion, and generation of microvesicles may lead to increased vascular resistance as well as increased cell-cell interactions that promote rolling and adhesion. Platelets may also contribute in a similar fashion. Lastly, the vasculature is also increasingly appreciated, as several studies have demonstrated increased endothelial expression of pro-coagulant and pro-adhesive proteins, such as von Willebrand factor or P-selectin in JAK2^V617F endothelial cells. With the advent of molecular diagnostics, MPN therapeutics are advancing beyond cytoreduction. Our increased understanding of pro-inflammatory and thrombotic pathophysiology in MPN provides a rational basis for evaluation of in-development MPN therapeutics to reduce thrombosis.

Hemorrhage in Essential Thrombocythemia or Polycythemia Vera: Epidemiology, Location, Risk Factors, and Lessons Learned from the Literature

Hemorrhage is a well-known complication of essential thrombocythemia (ET) and polycythemia vera (PV), but evidence-based data on its management and prevention are lacking to help inform clinicians. In this review, appropriate published data from the past 15 years regarding bleeding epidemiology, classification, location, and risk factors are presented and discussed. Research was conducted using the Medline database. The bleeding classifications were heterogeneous among the collected studies. The median incidences of bleeding and major bleeding were 4.6 and 0.79% patients/year, in ET patients and 6.5 and 1.05% patients/year in PV patients, respectively. The most frequent location was the gastrointestinal tract. Bleeding accounted for up to 13.7% of deaths, and cerebral bleeding was the main cause of lethal hemorrhage. Thirty-nine potential risk factors were analyzed at least once, but the results were discrepant. Among them, age >60 years, bleeding history, splenomegaly, myeloproliferative neoplasm subtype, and platelet count should deserve more attention in future studies. Among the treatments, aspirin seemed to be problematic for young patients with ET (especially CALR-mutated ET patients) and anagrelide was also identified as a bleeding inducer, especially when associated with aspirin. Future studies should analyze bleeding risk factors in more homogeneous populations and with common bleeding classifications. More tools are needed to help clinicians manage the increased risk of potentially lethal bleeding events in these diseases.

Impact of platelets on major thrombosis in patients with a normal white blood cell count in essential thrombocythemia

Objectives

Cell counts have a significant impact on the complex mechanism of thrombosis in patients with essential thrombocythemia (ET). We recently demonstrated a considerable impact of white blood cell (WBC) counts on thrombotic risk in patients with optimized platelet counts by analysing a large anagrelide registry. In contrast, the current analysis of the registry aimed to estimate the influence of platelet counts on thrombotic risk in patients with optimized WBC counts.

Methods

Cox regression analysis and Kaplan‐Meier plot were applied on all patients in the registry with optimized WBC counts.

Results

By using the calculated cut‐off of 593 G/L for platelets, Cox regression analysis revealed a clear influence of elevated platelet counts on the occurrence of a major thrombotic event (P < .001). A Kaplan‐Meier plot revealed a markedly shorter time to a major thrombotic event for patients with platelet counts above the cut‐off (P < .001).

Conclusions

The data show clear impact of platelet lowering on the thrombotic risk in ET patients with normal WBC counts. Therefore, selective platelet lowering with anagrelide appears sufficient for thrombotic risk reduction in WHO‐diagnosed ET patients lacking leukocytosis.

Correlation Between PAI-1 Gene 4G/5G Polymorphism and the Risk of Thrombosis in Ph Chromosome-Negative Myeloproliferative Neoplasms

Thrombosis has been recognized as one of the most significant risk factors of high mortality and disability in patients with Philadelphia (Ph) chromosome negative myeloproliferative neoplasms (MPNs). However, the risk factors of thrombotic events in these patients have not been completely understood. In this study, the clinical data of 58 patients with Ph-MPNs were obtained and analyzed, including 34 cases of essential thrombocytopenia (ET), 23 thrombotic events happened in 21 (36%) patients, among which 60% (14 of 23) with cerebral infarction, 17% (4 of 23) with coronary heart disease and 23% (5 of 23) with venous thrombosis. There were no significant differences in age, sex, and blood cell count between polycythemia vera (PV) and ET patients who have experienced thrombotic events and those who have not. In ET patients, the incidence of thrombotic events in plasminogen activator inhibitor-1 (PAI-1) genotype 4G4G was significantly higher than that in genotype 4G5G and genotype 5G5G (P < .05). The incidence of thrombotic events in PV and ET patients with infection was higher than those without infection (P < .05). Using logistic regression analysis, we found that PAI-1 genotype 4G4G and infection were associated with thrombotic events (odds ratio 6.744, 95% CI: 1.195-38.056 and 15.641 95% CI: 3.327-73.522). The 4G/4G polymorphism of PAI-1 gene and infection are independent risk factors of thrombotic events in patients with Ph-MPNs. PAI-1 gene 4G4G and infection in ET and PV patients with Janus kinase 2 (JAK2) V617F mutation were shown to be high risk of thrombotic events. Therefore, clinical doctors should put more attention on PAI-1 genotype 4G4G and infection in JAK2 V617F mutated patients with Ph-MPNs to prevent the thrombosis.