Thrombocytosis and bleeding in myeloproliferative neoplasms: exploring clinical diversity and risk of acquired Von Willebrand Syndrome – insights from a UK centre
File(s)
Published version (pre-proof)
Author(s)
Type
Journal Article
Abstract
Background
Myeloproliferative neoplasms (MPNs) represent a group of blood disorders characterized by myeloid cell proliferation and an associated increased risk of thrombosis and bleeding. Platelet count may have a direct link with these complications.
Aims
To share our MPN clinic’s experience on haemostatic testing and bleeding outcomes in patients with platelets ≥800 x109/L.
Methods
Single centre retrospective study from May 2022 to September 2024.
Clinical characteristics, treatments, and bleeding events of patients with MPN or chronic myeloid leukaemia (CML) were recorded. Laboratory assessments included full blood count, renal function, coagulation profiles, platelet function test (PFA-100) and von Willebrand factor (VWF) assays.
Results
A total of 39 patients were included, majority of whom received aspirin for thrombosis prevention (76%). The study found that bleeding complications occurred in 33% of patients, with mucocutaneous bleeding being the most common. There was a trend towards bleeding in patients on aspirin (P=0.07). However, platelet count alone did not predict bleeding risk. While some patients showed abnormal VWF function, low VWF levels were not consistently associated with increased bleeding. Interestingly, we found moderate negative correlation between baseline VWF:RCo/Ag and activated partial thromboplastin time (P=0.02, r=-0.373), and prothrombin time (P=0.009, r=-0.447), suggesting other potential coagulation imbalances associated with bleeding diathesis in MPNs. Post cyto-reduction, there was a significant increase in mean VWF:RCo/Ag ratio (P=0.0009).
Conclusions
The study illustrates the limitations of relying solely on platelet counts to estimate bleeding risk in MPN patients. Assessment of VWF activity, and careful selection of antithrombotic therapy were highlighted as important considerations.
Myeloproliferative neoplasms (MPNs) represent a group of blood disorders characterized by myeloid cell proliferation and an associated increased risk of thrombosis and bleeding. Platelet count may have a direct link with these complications.
Aims
To share our MPN clinic’s experience on haemostatic testing and bleeding outcomes in patients with platelets ≥800 x109/L.
Methods
Single centre retrospective study from May 2022 to September 2024.
Clinical characteristics, treatments, and bleeding events of patients with MPN or chronic myeloid leukaemia (CML) were recorded. Laboratory assessments included full blood count, renal function, coagulation profiles, platelet function test (PFA-100) and von Willebrand factor (VWF) assays.
Results
A total of 39 patients were included, majority of whom received aspirin for thrombosis prevention (76%). The study found that bleeding complications occurred in 33% of patients, with mucocutaneous bleeding being the most common. There was a trend towards bleeding in patients on aspirin (P=0.07). However, platelet count alone did not predict bleeding risk. While some patients showed abnormal VWF function, low VWF levels were not consistently associated with increased bleeding. Interestingly, we found moderate negative correlation between baseline VWF:RCo/Ag and activated partial thromboplastin time (P=0.02, r=-0.373), and prothrombin time (P=0.009, r=-0.447), suggesting other potential coagulation imbalances associated with bleeding diathesis in MPNs. Post cyto-reduction, there was a significant increase in mean VWF:RCo/Ag ratio (P=0.0009).
Conclusions
The study illustrates the limitations of relying solely on platelet counts to estimate bleeding risk in MPN patients. Assessment of VWF activity, and careful selection of antithrombotic therapy were highlighted as important considerations.
Date Issued
2025-06-24
Date Acceptance
2025-06-18
Citation
Research and Practice in Thrombosis and Haemostasis, 2025
ISSN
2475-0379
Publisher
Elsevier
Journal / Book Title
Research and Practice in Thrombosis and Haemostasis
Copyright Statement
© 2025 Published by Elsevier Inc. on behalf of International Society on Thrombosis and Haemostasis.
License URL
Identifier
10.1016/j.rpth.2025.102954
Publication Status
Published online
Article Number
102954
Date Publish Online
2025-06-24