Thrombosis is a common complication of myeloproliferative neoplasm (MPN), and it is a major cause of disability and death. With the development of next-generation gene-sequencing technology, the relationship between non-driver mutations and thrombotic risk factors has also attracted considerable attention. To analyze the risk factors of thrombosis in patients with essential thrombocythemia (ET) and polycythemia vera (PV), we retrospectively analyzed the clinical data of 125 MPN patients (75 ET and 50 PV) and performed a multivariate analysis of the risk factors of thrombosis using a Cox proportional risk model. Among the 125 patients, 35 (28.0%) had thrombotic events, and the incidence of thrombotic events was 21.3% and 38.0% in ET and PV patients, respectively. In ET patients, the multivariate analysis showed that a TET2 mutation and history of remote thrombosis were independent risk factors for thrombosis in ET patients, with an HR of 4.1 (95% CI: 1.40–12.01; p = 0.01) for TET2 mutation and 6.89 (95% CI: 1.45–32.68; p = 0.015) for a history of remote thrombosis. In PV patients, the multivariate analysis presented the neutrophil-to-lymphocyte ratio (NLR) (HR: 4.77, 95% CI: 1.33–17.16; p = 0.017) and a history of remote thrombosis (HR: 1.67, 95% CI: 1.03–1.32; p = 0.014) as independent risk factors for thrombosis, with no significant change in the risk of thrombosis in patients with TET2 mutations. A further analysis of the clinical characteristics and coagulation occurring in ET patients with a TET2 mutation revealed that the values of age and D-dimer were significantly higher and antithrombin III was significantly lower in TET2-mutated ET patients compared to TET2-unmutated patients. In summary, TET2 mutation may be more valuable in predicting thrombosis in ET patients than in PV patients. ET patients with a TET2 mutation are older and present differences in coagulation compared to TET2-unmutated patients.

Thrombotic events are the most frequent manifestations of essential thrombocythemia (ET). The objective of this study is to determine the incidence of thrombosis at different sites on follow-up in patients with ET. We searched PubMed, Web of Science, and The Cochrane Library databases and calculated the incidence of thrombosis by pooling and analyzing the extracted data using a random-effects model. A total of 70 studies (N = 25,805) were included in the analysis. The total and annual incidences of arterial thrombosis on follow-up were 13.4% and 2.0%, respectively. The total and annual incidences of the different manifestations of arterial thrombosis were as follows: stroke (5.3% and 0.8%), transient ischemic attack (5.1% and 1.2%), myocardial infarction (2.4% and 0.5%), unstable angina (0.9% and 0.2%), and peripheral arterial thrombosis (2.0% and 0.2%), respectively. In contrast, the total and annual incidences of arterial thrombosis in JAK2-positive patients were 18.4% and 2.7%, respectively. The total and annual incidences of arterial thrombosis in JAK2-negative patients were 5.9% and 0.8%, respectively. The total and annual incidences of venous thrombosis were 5.5% and 0.7%, respectively, and the incidences of the different manifestations of venous thrombosis at different sites were as follows: peripheral venous thrombosis (2.9% and 0.5%), superficial venous thrombosis (1.8% and 0.7%), deep venous thrombosis (1.6% and 0.3%), abdominal venous thrombosis (0.8% and 0.1%), pulmonary embolism (0.3% and 0.1%), and cerebral venous thrombosis (0.2% and 0%), respectively. The total and annual incidences of venous thrombosis in JAK2-positive patients were 7.4% and 1.2%, respectively. The total and annual incidences of venous thrombosis in JAK2-negative patients were 1.6% and 0.4%, respectively. The incidence of arterial thrombosis was higher than that of venous thrombosis in patients with ET. Arterial thrombosis manifested with cerebral arterial thrombosis, followed by cardiac thrombosis. Venous thrombosis events were mainly peripheral and superficial venous thrombosis. JAK2-positive patients have a higher incidence of arterial and venous thromboses than JAK2-negative patients, the sequence of thrombsis sites was similar to that of the overall patients.

Abnormal platelet activation can lead to thrombosis in essential thrombocythemia (ET) and thus impact patient prognosis. Platelet activation-associated proteins are key molecules for platelet activation. However, it is unclear which proteins are most closely associated with the disease’s prognosis. To determine which platelet activation-related proteins can be employed as ET patient prognosis predictors, we used label-free quantification (LFQ) and parallel reaction monitoring (PRM) technology and first determined the serum proteomic expression levels and the differential proteins of ET patients. Then, based on the IPSET (International Prognostic Score for ET), the differential protein associated with the prognostic score was found. To investigate potential processes affecting prognosis, the connection of this protein with prognostic markers, such as thrombotic history, age, white blood cell count, coagulation factors, and inflammatory factors, were further examined. The levels of platelet activation-related proteins GPIbα, SELP, PF4, MMP1, and FLNA were significantly higher in ET patients, according to LFQ and PRM analyses (p < 0.01). Based on regression analysis of the IPSET prognostic score, it is suggested that the SELP level was positively correlated with the prognostic score and prognostic risk factor analysis (p < 0.05). Further regression analysis of SELP with coagulation factors showed that antithrombin (AT-III) was negatively correlated with SELP levels (p < 0.05). Further regression analysis of the inflammatory factors with AT-III and SELP revealed that IL-10, IL-12P70, and IL-31 were negatively correlated with AT-III and SELP (p < 0.01). Platelet activation pathway-related proteins are expressed more frequently in ET patients, and serum SELP may be a prognostic marker for these individuals by encouraging leukocyte increase and inflammatory factor expression and causing aberrant coagulation.

Polycythemia vera (PV) is a malignant clonal hematological disease of hematopoietic stem cells characterized by the proliferation of peripheral blood cells, and JAK2 mutation is one of the main causes of PV peripheral blood cell proliferation. Abnormal cell metabolism is a new feature of malignant proliferation of tumor cells, but the role of metabolism in the pathogenesis and prognosis of PV remains unclear. We analyzed metabolic differences of peripheral blood sera between 32 PV patients and 20 healthy controls (HCs) by liquid chromatography–mass spectrometry (LC–MS) to investigate their relationship with cell proliferation and to screen for prognosis-related metabolic biomarkers. Compared to HC, 33 endogenous metabolites were significantly changed in PV and were involved in fatty acid metabolism, glucose metabolism, sphingolipid metabolism, and amino acid metabolism pathways. Among them, seven metabolites were closely associated with JAK2 mutations, 2 of which may contribute to the proliferation of peripheral blood cells in PV patients. A set of potential prognostic metabolic biomarkers containing four metabolites was identified by a receiver operating characteristic (ROC) curve according to the risk stratification of the PV patients and their combined AUC value of 0.952, with a sensitivity of 90.905% and specificity of 90.909% at the optimal cutoff point. Metabonomics is an important tool for the study of the pathogenesis of PV and the relationship between JAK2 gene mutation. Furthermore, the potential biomarkers of this study may provide a reference for the prognosis of PV.