DNMT3A, TET2, and ASXL1 (DTA) Mutations Are Associated with Thrombosis and Bleeding in Patients with Myeloproliferative Neoplasms

Background: Patients with myeloproliferative neoplasms (MPNs) including polycythemia vera (PV), essential thrombocytosis (ET), and primary or secondary myelofibrosis (MF), have a remarkably increased risk of thrombotic events (TEs). Scores to assess the risk of thrombosis are limited, while some patients paradoxically suffer from bleeding complications that are even less predictable. Next-generation sequencing (NGS) enables detection of somatic mutations in myeloid-related genes, in addition to the common driver mutations in JAK2, CALR, and MPL. Mutations in DNMT3A, TET2 and ASXL1 (collectively, DTA) are associated with an increased risk of arterial TEs in individuals with clonal hematopoiesis [Jaiswal, NEJM 2017]. Several recent studies addressed the relationship between DTA mutations and thrombohemorrhagic complications in MPN, however, results have been inconsistent and mostly focused on PV.

Methods: We evaluated the association between NGS mutational panel data and thrombohemorrhagic complications in patients with MPN admitted for evaluation in our institution between 2020-2023. NGS was performed on DNA extracted from bone marrow samples, using the Archer VariantPlex Myeloid panel. Clinical and demographic data were collected retrospectively from electronic medical records. The study was approved by the local IRB [HMO-0533-19].

Results: 154 patients were included in the study. Median age was 65 years and 52% were female. 50% had a diagnosis of PV, 33% essential thrombocytosis ET, and 17% primary or secondary MF. 75% of the patients harbored a JAK2 V617F mutation, 14% and 3% harbored CALR and MPL mutations, respectively, and 8% were negative for all three MPN driver mutations. In NGS analyses, over 60% of the patients harbored at least one additional mutation; 45% harbored one or more DTA mutations. 67% of the patients had at least one cardiovascular risk factor, 73% had high-risk disease defined by age>60 years or history of thrombosis, and over 70% received at least one line of cytoreductive therapy. Of 154 patients, 35% had a history of TEs (20% arterial, 15% venous) and 25% had experienced major or minor bleeding events. The high prevalence of bleeding manifestations in our study population may suggest an underestimation of the bleeding burden in MPN.

In the entire patient population, the presence of hypertension (OR 3.5, 95% CI 1.6-7.9, p = 0.002), diabetes mellitus (OR 3.3, 95% CI 1.2-8.2, p = 0.01), and JAK2 V617F (OR 2.4, 95% CI 1.1-5.6, p = 0.04) were significantly associated with the occurrence of TEs, while DTA mutations were not. However, in the PV subgroup, DTA as well as TET2 mutations specifically were significantly associated with venous TEs (OR 3.750, 95% CI 1.0-11.8, p = 0.04). Age was not found to be associated with the occurrence of TEs in this cohort, perhaps owing to a large proportion of high-risk disease in younger patients.

Hypertension was also a significant predictor of major bleeding events (OR 4.5, 95% CI 1.2-15.8, p = 0.02). We observed a significant association between DTA mutations and major bleeding (OR 2.8, 95% CI 1.04-7.9, p = 0.04), previously reported only in patients with ET and DNMT3A mutations [Furuya, BJH, 2024]. A significant association was also observed between JAK2 V617F allelic burden and total bleeding events (OR 1.17 for each 10% increase, p = 0.003), not previously reported in MPN. In multivariate analysis, DTA mutations retained significance as a predictor of hemorrhagic complications.

Conclusions: DTA mutations detected with a clinically used NGS panel in patients with MPN are associated with increased risk of bleeding complications, as well as increased thrombotic risk in a subgroup of patients. These findings support the incorporation of molecular panel analyses in thrombosis and bleeding risk assessment in MPN, and merit further investigation.