It is time to change thrombosis risk assessment for PV and ET?

Vascular target organ damage in patients with Philadelphia negative myeloproliferative syndrome: A propensity score analysis

PURPOSE

To assess whether subjects with Philadelphia negative myeloproliferative neoplasms (Ph-MPNs) show differences in the presence of vascular, cardiac or renal target organ damage (TOD) and other vascular function parameters as compared to individuals without this condition.

METHODS

An observational study was conducted. Fifty-seven subjects diagnosed with Ph-MPNs used as cases and 114 subjects without Ph-MPNs as controls. We matched the subjects with and without Ph-MPNs using the propensity scores in a 1:2 ratio using the variables gender, type 2 diabetes mellitus, high blood pressure, hyperlipidaemia and smoking. Vascular, cardiac and renal TOD were established according to the criteria of the European Society of Hypertension and Cardiology guidelines. Arterial stiffness was also assessed using the cardio-ankle vascular index (CAVI).

RESULTS

Mean age was 63.50±11.70 and 62.90±8.32 years in subjects with and without Ph-MPNs, 32 females (56%) in the first group and 62 (54%) in the second. Subjects with Ph-MPNs have a higher percentage of carotid injury than subjects without Ph-MPNs (35.1% vs. 21.1%) and higher albumin/creatinine ratio. In the logistic regression analysis, subjects with Ph-MPNs had an OR=2.382 (IC95% 1.066-5.323) for carotid injury versus those without haematological disease.

CONCLUSIONS

Subjects with Ph-MPNs have twice the risk of by carotid injury than those without haematological disease.

Clinico-hematological profile and thrombotic/hemorrhagic events in 150 chinese patients with essential thrombocythemia

Essential thrombocythemia (ET) is an uncommon chronic myeloproliferative disorder with no cure. Patients with ET are at risk of different complications, and currently there are no optimal prognostic standards to predict severe post-diagnosis complications such as thrombosis and hemorrhage. In this study, we retrospectively analyzed the full set of clinical data from 150 Chinese patients with ET enrolled from 2013 to 2016. We discovered that neutrophil-to-lymphocyte ratio (NLR), along with other known clinical parameters such as age, leukocyte count, incidence of thrombotic events is higher in patients with JAK2 V617F mutation. NLR is also higher in patients at high-risk stratification of thrombosis. Multivariate analysis showed that age (P = 0.001, 95% CI 1.023-1.089) and JAK2 V617F mutation (P = 0.003, 95% CI 1.837-21.035) were independent factors for thrombotic events, while age (P = 0.005, 95% CI 1.019-1.111) was the only predictive factor for hemorrhagic events at diagnosis. For future thrombotic events, multivariate analysis revealed NLR as the best predictive parameter (P < 0.001, 95% CI 1.173-1.486) when compared with other clinical parameters such as age (P = 0.037, 95% CI 1.004-1.126), thrombosis at diagnosis (P = 0.036, 95% CI 1.077-9.099) and WBC count (P = 0.047, 95% CI 1.001-1.109). Further ROC curve and Kaplan Meier analysis validated NLR as better prognostic marker for future thrombotic events and thrombosis-free survival. In summary, our data suggest that NLR parameter may possess great prognostic significance for future thrombosis in ET patients.

Phosphatidylserine-exposing blood and endothelial cells contribute to the hypercoagulable state in essential thrombocythemia patients

The mechanisms of thrombogenicity in essential thrombocythemia (ET) are complex and not well defined. Our objective was to explore whether phosphatidylserine (PS) exposure on blood cells and endothelial cells (ECs) can account for the increased thrombosis and distinct thrombotic risks among mutational subtypes in ET. Using flow cytometry and confocal microscopy, we found that the levels of PS-exposing erythrocytes, platelets, leukocytes, and serum-cultured ECs were significantly higher in each ET group [JAK2, CALR, and triple-negative (TN) (all P < 0.001)] than those in controls. Among ET patients, those with JAK2 mutations showed higher levels of PS-positive erythrocytes, platelets, neutrophils, and serum-cultured ECs than TN patients or those with CALR mutations, which show similar levels. Coagulation function assays showed that higher levels of PS-positive blood cells and serum-cultured ECs led to markedly shortened coagulation time and dramatically increased levels of FXa, thrombin, and fibrin production. This procoagulant activity could be largely blocked by addition of lactadherin (approx. 70% inhibition). Confocal microscopy showed that the FVa/FXa complex and fibrin fibrils colocalized with PS on ET serum-cultured ECs. Additionally, we found a relationship between D-dimer, prothrombin fragment F1 + 2, and PS exposure. Our study reveals a previously unrecognized link between hypercoagulability and exposed PS on cells, which might also be associated with distinct thrombotic risks among mutational subtypes in ET. Thus, blocking PS-binding sites may represent a new therapeutic target for preventing thrombosis in ET.

High platelet count at diagnosis is a protective factor for thrombosis in patients with essential thrombocythemia

To assess the role of platelet (PLT) count for thrombotic complications in Essential Thrombocythemia (ET), 1201 patients followed in 11 Hematological centers in the Latium region were retrospectively evaluated. At multivariate analysis, the following factors at diagnosis were predictive for a worse Thrombosis-free Survival (TFS): the occurrence of previous thrombotic events (p=0.0004), age>60years (p=0.0044), spleen enlargement (p=0.042) and a lower PLT count (p=0.03). Receiver Operating Characteristic (ROC) analyses based on thrombotic events during follow-up identified a baseline platelet count of 944×10⁹/l as the best predictive threshold: thrombotic events were 40/384 (10.4%) in patients with PLT count >944×10⁹/l and 109/817 (13.3%) in patients with PLT count <944×10⁹/l, respectively (p=0.04). Patients with PLT count <944×10⁹/l were older (median age 60.4years. vs 57.1years., p=0.016), had a lower median WBC count (8.8×10⁹/l vs 10.6×10⁹/l, p<0.0001), a higher median Hb level (14.1g/dl vs 13.6g/dl, p<0.0001) and a higher rate of JAK-2-V617F positivity (67.2% vs 41.6%, p<0.0001); no difference was observed as to thrombotic events before diagnosis, spleen enlargement and concomitant Cardiovascular Risk Factors. In conclusion, our results confirm the protective role for thrombosis of an high PLT count at diagnosis. The older age and the higher rate of JAK-2 V617F positivity in the group of patients with a baseline lower PLT count could in part be responsible of this counterintuitive finding.

Persistent neutrophilia is a marker for an increased risk of venous thrombosis

In patients with cancer and myeloproliferative disorders, leukocytosis has been associated with an increased venous thromboembolic (VTE) risk. Our goal was to determine whether persistent neutrophilia (PN), not associated with known causes such as malignancies, infections or steroids, is independently associated with VTE. All adult patients with >3 outpatient complete blood counts (CBCs) within 3 years were included. PN was defined as having an absolute neutrophil count >95 % (>2SD) of the population (≥7.8 × 10(9)/L) on at least three CBCs, at least 2 months apart. Separate analyses for neutrophil counts ≥9 × 10(9)/L and ≥10 × 10(9)/L were also performed. Blood counts from inpatients were excluded. Primary outcome was diagnosis of VTE, as determined by ICD-9 codes. Odds ratios were adjusted for diabetes, smoking, obesity, gender, and age. Charlson score was utilized as a morbidity measure. Data on 43,538 outpatients were collected. Although there was no association of VTE with neutrophil counts ≥7.8 × 10(9)/L, patients with ≥9.0 × 10(9)/L neutrophils were twice as likely to be diagnosed with VTE compared to those with normal neutrophil counts (OR 2.0, 95 % CI 1.3, 3.1; p = 0.003). Patients with neutrophil counts ≥10.0 × 10(9)/L were at an even higher risk (OR 2.3, 95 % CI 1.2, 4.8; p = 0.019). Charlson scores significantly modified this risk when incorporated into analysis. Elevated neutrophil counts are associated with an increased risk of venous thrombosis even when they are not due to cancer, infection or steroids. In patients with significant comorbidities, neutrophilia may be a marker of VTE risk.

An Overview of Thrombophilia and Associated Laboratory Testing

Venous thromboembolism, usually entailing deep vein thrombosis, pulmonary embolism, or both, is a complex and multifactorial disorder, in which a number of putative conditions interplay and finally contribute to propel the individual risk over a certain degree, so ultimately culminating in the development of venous occlusive disorders. Thrombophilia is commonly defined as a propensity to develop venous thromboembolism on the basis of an underlying hypercoagulable state attributable to inherited or acquired disorders of blood coagulation or fibrinolysis. The thrombophilic conditions are conventionally classified as inherited (or genetically determined) and acquired. The former include deficiencies of natural anticoagulants such as antithrombin, protein C, protein S, increased values of clotting factors (especially factor VIII), as well as prothrombotic polymorphisms in genes encoding for factor V (i.e., factor V Leiden) and prothrombin. The latter conditions mainly entail antiphospholipid antibody syndrome, malignancy, acquired elevations of coagulation factors or acquired reduction of natural inhibitors, or hyperhomocysteinemia. Deepened knowledge of all potential risk factors, as well as the clear understanding of their role in the pathophysiology of venous thrombosis, are both essential to help achieve a faster and more efficient diagnosis of this condition as well as a more effective prophylaxis of patients at higher risk and treatment of those with manifest disease.

Thrombotic risk correlates with mutational status in true essential thrombocythemia

BACKGROUND

True essential thrombocythemia (ET) may carry one of the known driver mutations (JAK2, MPL and CALR) or none of them [in triple-negative (3NEG) cases]. The patients' mutational status seems to delineate the clinical manifestations of ET.

MATERIALS AND METHODS

We report the data of 183 patients diagnosed with ET strictly according to the WHO 2008 criteria and with a full molecular diagnosis, including the following: 114 patients (62·3%) with JAK2V617F; 25 (13·7%) with CALR type 1 and 19 (10·4%) with CALR type 2; 3 (1·6%) with MPL; 22 (12%) who were 3NEG. Thrombotic risk was assessed by means of the IPSET-thrombosis score (IPSET-T).

RESULTS

CALR and 3NEG patients had lower haemoglobin levels and leucocyte count than JAK2 patients. CALR patients, and those with type 2 in particular, had higher mean platelet counts and had extreme thrombocytosis more often than any of the other groups. Based on their IPSET-T stratification, 3NEG- and CALR-mutated patients belonged more frequently to the low-risk group and had a significant more favourable thrombosis-free survival rate than those with JAK2 mutation.

CONCLUSION

These findings indicate that the three different molecular markers have a significant impact on the clinical course of true ET, giving rise to different phenotypes of the same disease.

[Thrombotic events and significance of the IPSET thrombosis risk evaluation score in essential thrombocythaemia]

INTRODUCTION

Thrombo-haemorrhagic complications contribute to both morbidity and mortality in patients with essential thrombocythaemia.

AIM

The aim of the authors was to estimate the incidence of thrombotic events and to examine the clinical utility of IPSET thrombosis risk evaluation score against conventional two-categorical (low and high) risk assessment.

METHOD

A retrospective analysis was carried out on 155 patients with essential thrombocythaemia (106 females; median age, 61 years) in a period between 1999 and 2014.

RESULTS

The analysis revealed 55 (35.5%) major thrombotic events before and 25 (16.1%) major thrombotic complications after establishment of the haematologic diagnosis. Significant differences were observed in thrombosis-free survival between the different IPSET groups (p = 0.002).

CONCLUSIONS

The IPSET model was first examined in this cohort of patients with essential thrombocythaemia diagnosed in a single Hungarian haematologic centre. The results suggest that this score may provide more information than the conventional thrombosis risk assessment.